<!--page 3 -->
</pre>
-<a name="Contents" href="#Contents"><h2>Contents</h2></a>
+<h2><a name="Contents" href="#Contents">Contents</a></h2>
<ul>
<li><a href="#Foreword">Foreword</a>
<li><a href="#Introduction">Introduction</a>
<!--page 13 -->
</ul>
-<a name="Foreword" href="#Foreword"><h2>Foreword</h2></a>
+<h2><a name="Foreword" href="#Foreword">Foreword</a></h2>
<p><!--para 1 -->
ISO (the International Organization for Standardization) and IEC (the International
Electrotechnical Commission) form the specialized system for worldwide
are also for information only.
<!--page 17 -->
-<a name="Introduction" href="#Introduction"><h2>Introduction</h2></a>
+<h2><a name="Introduction" href="#Introduction">Introduction</a></h2>
<p><!--para 1 -->
With the introduction of new devices and extended character sets, new features may be
added to this International Standard. Subclauses in the language and library clauses warn
-<a name="1" href="#1"><h2>1. Scope</h2></a>
+<h2><a name="1" href="#1">1. Scope</a></h2>
<p><!--para 1 -->
This International Standard specifies the form and establishes the interpretation of
programs written in the C programming language.<sup><a href="#note1"><b>1)</b></a></sup> It specifies
data-processing systems. It is intended for use by implementors and programmers.
</small>
-<a name="2" href="#2"><h2>2. Normative references</h2></a>
+<h2><a name="2" href="#2">2. Normative references</a></h2>
<p><!--para 1 -->
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
designated IEC 559:1989).
<!--page 21 -->
-<a name="3" href="#3"><h2>3. Terms, definitions, and symbols</h2></a>
+<h2><a name="3" href="#3">3. Terms, definitions, and symbols</a></h2>
<p><!--para 1 -->
For the purposes of this International Standard, the following definitions apply. Other
terms are defined where they appear in italic type or on the left side of a syntax rule.
Standard are to be interpreted according to ISO/IEC 2382-1. Mathematical symbols not
defined in this International Standard are to be interpreted according to ISO 31-11.
-<a name="3.1" href="#3.1"><h3>3.1</h3></a>
+<h3><a name="3.1" href="#3.1">3.1</a></h3>
<p><!--para 1 -->
- access
+<b> access</b><br>
<execution-time action> to read or modify the value of an object
<p><!--para 2 -->
NOTE 1 Where only one of these two actions is meant, ''read'' or ''modify'' is used.
NOTE 3 Expressions that are not evaluated do not access objects.
-<a name="3.2" href="#3.2"><h3>3.2</h3></a>
+<h3><a name="3.2" href="#3.2">3.2</a></h3>
<p><!--para 1 -->
- alignment
+<b> alignment</b><br>
requirement that objects of a particular type be located on storage boundaries with
addresses that are particular multiples of a byte address
-<a name="3.3" href="#3.3"><h3>3.3</h3></a>
+<h3><a name="3.3" href="#3.3">3.3</a></h3>
<p><!--para 1 -->
- argument
+<b> argument</b><br>
actual argument
actual parameter (deprecated)
expression in the comma-separated list bounded by the parentheses in a function call
expression, or a sequence of preprocessing tokens in the comma-separated list bounded
by the parentheses in a function-like macro invocation
-<a name="3.4" href="#3.4"><h3>3.4</h3></a>
+<h3><a name="3.4" href="#3.4">3.4</a></h3>
<p><!--para 1 -->
- behavior
+<b> behavior</b><br>
external appearance or action
-<a name="3.4.1" href="#3.4.1"><h4>3.4.1</h4></a>
+<h4><a name="3.4.1" href="#3.4.1">3.4.1</a></h4>
<p><!--para 1 -->
- implementation-defined behavior
+<b> implementation-defined behavior</b><br>
unspecified behavior where each implementation documents how the choice is made
<p><!--para 2 -->
EXAMPLE An example of implementation-defined behavior is the propagation of the high-order bit
when a signed integer is shifted right.
-<a name="3.4.2" href="#3.4.2"><h4>3.4.2</h4></a>
+<h4><a name="3.4.2" href="#3.4.2">3.4.2</a></h4>
<p><!--para 1 -->
- locale-specific behavior
+<b> locale-specific behavior</b><br>
behavior that depends on local conventions of nationality, culture, and language that each
implementation documents
<!--page 22 -->
characters other than the 26 lowercase Latin letters.
-<a name="3.4.3" href="#3.4.3"><h4>3.4.3</h4></a>
+<h4><a name="3.4.3" href="#3.4.3">3.4.3</a></h4>
<p><!--para 1 -->
- undefined behavior
+<b> undefined behavior</b><br>
behavior, upon use of a nonportable or erroneous program construct or of erroneous data,
for which this International Standard imposes no requirements
<p><!--para 2 -->
EXAMPLE An example of undefined behavior is the behavior on integer overflow.
-<a name="3.4.4" href="#3.4.4"><h4>3.4.4</h4></a>
+<h4><a name="3.4.4" href="#3.4.4">3.4.4</a></h4>
<p><!--para 1 -->
- unspecified behavior
+<b> unspecified behavior</b><br>
use of an unspecified value, or other behavior where this International Standard provides
two or more possibilities and imposes no further requirements on which is chosen in any
instance
evaluated.
-<a name="3.5" href="#3.5"><h3>3.5</h3></a>
+<h3><a name="3.5" href="#3.5">3.5</a></h3>
<p><!--para 1 -->
- bit
+<b> bit</b><br>
unit of data storage in the execution environment large enough to hold an object that may
have one of two values
<p><!--para 2 -->
NOTE It need not be possible to express the address of each individual bit of an object.
-<a name="3.6" href="#3.6"><h3>3.6</h3></a>
+<h3><a name="3.6" href="#3.6">3.6</a></h3>
<p><!--para 1 -->
- byte
+<b> byte</b><br>
addressable unit of data storage large enough to hold any member of the basic character
set of the execution environment
<p><!--para 2 -->
bit.
-<a name="3.7" href="#3.7"><h3>3.7</h3></a>
+<h3><a name="3.7" href="#3.7">3.7</a></h3>
<p><!--para 1 -->
- character
+<b> character</b><br>
<abstract> member of a set of elements used for the organization, control, or
representation of data
-<a name="3.7.1" href="#3.7.1"><h4>3.7.1</h4></a>
+<h4><a name="3.7.1" href="#3.7.1">3.7.1</a></h4>
<p><!--para 1 -->
- character
+<b> character</b><br>
single-byte character
<C> bit representation that fits in a byte
<!--page 23 -->
-<a name="3.7.2" href="#3.7.2"><h4>3.7.2</h4></a>
+<h4><a name="3.7.2" href="#3.7.2">3.7.2</a></h4>
<p><!--para 1 -->
- multibyte character
+<b> multibyte character</b><br>
sequence of one or more bytes representing a member of the extended character set of
either the source or the execution environment
<p><!--para 2 -->
NOTE The extended character set is a superset of the basic character set.
-<a name="3.7.3" href="#3.7.3"><h4>3.7.3</h4></a>
+<h4><a name="3.7.3" href="#3.7.3">3.7.3</a></h4>
<p><!--para 1 -->
- wide character
+<b> wide character</b><br>
bit representation that fits in an object of type wchar_t, capable of representing any
character in the current locale
-<a name="3.8" href="#3.8"><h3>3.8</h3></a>
+<h3><a name="3.8" href="#3.8">3.8</a></h3>
<p><!--para 1 -->
- constraint
+<b> constraint</b><br>
restriction, either syntactic or semantic, by which the exposition of language elements is
to be interpreted
-<a name="3.9" href="#3.9"><h3>3.9</h3></a>
+<h3><a name="3.9" href="#3.9">3.9</a></h3>
<p><!--para 1 -->
- correctly rounded result
+<b> correctly rounded result</b><br>
representation in the result format that is nearest in value, subject to the current rounding
mode, to what the result would be given unlimited range and precision
-<a name="3.10" href="#3.10"><h3>3.10</h3></a>
+<h3><a name="3.10" href="#3.10">3.10</a></h3>
<p><!--para 1 -->
- diagnostic message
+<b> diagnostic message</b><br>
message belonging to an implementation-defined subset of the implementation's message
output
-<a name="3.11" href="#3.11"><h3>3.11</h3></a>
+<h3><a name="3.11" href="#3.11">3.11</a></h3>
<p><!--para 1 -->
- forward reference
+<b> forward reference</b><br>
reference to a later subclause of this International Standard that contains additional
information relevant to this subclause
-<a name="3.12" href="#3.12"><h3>3.12</h3></a>
+<h3><a name="3.12" href="#3.12">3.12</a></h3>
<p><!--para 1 -->
- implementation
+<b> implementation</b><br>
particular set of software, running in a particular translation environment under particular
control options, that performs translation of programs for, and supports execution of
functions in, a particular execution environment
-<a name="3.13" href="#3.13"><h3>3.13</h3></a>
+<h3><a name="3.13" href="#3.13">3.13</a></h3>
<p><!--para 1 -->
- implementation limit
+<b> implementation limit</b><br>
restriction imposed upon programs by the implementation
-<a name="3.14" href="#3.14"><h3>3.14</h3></a>
+<h3><a name="3.14" href="#3.14">3.14</a></h3>
<p><!--para 1 -->
- memory location
+<b> memory location</b><br>
either an object of scalar type, or a maximal sequence of adjacent bit-fields all having
nonzero width
<!--page 24 -->
char a;
int b:5, c:11, :0, d:8;
struct { int ee:8; } e;
- }</pre>
+ }
+</pre>
contains four separate memory locations: The member a, and bit-fields d and e.ee are each separate
memory locations, and can be modified concurrently without interfering with each other. The bit-fields b
and c together constitute the fourth memory location. The bit-fields b and c cannot be concurrently
modified, but b and a, for example, can be.
-<a name="3.15" href="#3.15"><h3>3.15</h3></a>
+<h3><a name="3.15" href="#3.15">3.15</a></h3>
<p><!--para 1 -->
- object
+<b> object</b><br>
region of data storage in the execution environment, the contents of which can represent
values
<p><!--para 2 -->
NOTE When referenced, an object may be interpreted as having a particular type; see <a href="#6.3.2.1">6.3.2.1</a>.
-<a name="3.16" href="#3.16"><h3>3.16</h3></a>
+<h3><a name="3.16" href="#3.16">3.16</a></h3>
<p><!--para 1 -->
- parameter
+<b> parameter</b><br>
formal parameter
formal argument (deprecated)
object declared as part of a function declaration or definition that acquires a value on
entry to the function, or an identifier from the comma-separated list bounded by the
parentheses immediately following the macro name in a function-like macro definition
-<a name="3.17" href="#3.17"><h3>3.17</h3></a>
+<h3><a name="3.17" href="#3.17">3.17</a></h3>
<p><!--para 1 -->
- recommended practice
+<b> recommended practice</b><br>
specification that is strongly recommended as being in keeping with the intent of the
standard, but that may be impractical for some implementations
-<a name="3.18" href="#3.18"><h3>3.18</h3></a>
+<h3><a name="3.18" href="#3.18">3.18</a></h3>
<p><!--para 1 -->
- runtime-constraint
+<b> runtime-constraint</b><br>
requirement on a program when calling a library function
<p><!--para 2 -->
NOTE 1 Despite the similar terms, a runtime-constraint is not a kind of constraint as defined by <a href="#3.8">3.8</a>, and
constraints for a library function are not violated by the program; see <a href="#K.3.1.4">K.3.1.4</a>.
<!--page 25 -->
-<a name="3.19" href="#3.19"><h3>3.19</h3></a>
+<h3><a name="3.19" href="#3.19">3.19</a></h3>
<p><!--para 1 -->
- value
+<b> value</b><br>
precise meaning of the contents of an object when interpreted as having a specific type
-<a name="3.19.1" href="#3.19.1"><h4>3.19.1</h4></a>
+<h4><a name="3.19.1" href="#3.19.1">3.19.1</a></h4>
<p><!--para 1 -->
- implementation-defined value
+<b> implementation-defined value</b><br>
unspecified value where each implementation documents how the choice is made
-<a name="3.19.2" href="#3.19.2"><h4>3.19.2</h4></a>
+<h4><a name="3.19.2" href="#3.19.2">3.19.2</a></h4>
<p><!--para 1 -->
- indeterminate value
+<b> indeterminate value</b><br>
either an unspecified value or a trap representation
-<a name="3.19.3" href="#3.19.3"><h4>3.19.3</h4></a>
+<h4><a name="3.19.3" href="#3.19.3">3.19.3</a></h4>
<p><!--para 1 -->
- unspecified value
+<b> unspecified value</b><br>
valid value of the relevant type where this International Standard imposes no
requirements on which value is chosen in any instance
<p><!--para 2 -->
NOTE An unspecified value cannot be a trap representation.
-<a name="3.19.4" href="#3.19.4"><h4>3.19.4</h4></a>
+<h4><a name="3.19.4" href="#3.19.4">3.19.4</a></h4>
<p><!--para 1 -->
- trap representation
+<b> trap representation</b><br>
an object representation that need not represent a value of the object type
-<a name="3.19.5" href="#3.19.5"><h4>3.19.5</h4></a>
+<h4><a name="3.19.5" href="#3.19.5">3.19.5</a></h4>
<p><!--para 1 -->
- perform a trap
+<b> perform a trap</b><br>
interrupt execution of the program such that no further operations are performed
<p><!--para 2 -->
NOTE In this International Standard, when the word ''trap'' is not immediately followed by
representation might perform a trap but is not required to (see <a href="#6.2.6.1">6.2.6.1</a>).
</small>
-<a name="3.20" href="#3.20"><h3>3.20</h3></a>
+<h3><a name="3.20" href="#3.20">3.20</a></h3>
<p><!--para 1 -->
- [^ x^]
+<b> [^ x^]</b><br>
ceiling of x: the least integer greater than or equal to x
<p><!--para 2 -->
EXAMPLE [^2.4^] is 3, [^-2.4^] is -2.
-<a name="3.21" href="#3.21"><h3>3.21</h3></a>
+<h3><a name="3.21" href="#3.21">3.21</a></h3>
<p><!--para 1 -->
- [_ x_]
+<b> [_ x_]</b><br>
floor of x: the greatest integer less than or equal to x
<p><!--para 2 -->
EXAMPLE [_2.4_] is 2, [_-2.4_] is -3.
<!--page 26 -->
-<a name="4" href="#4"><h2>4. Conformance</h2></a>
+<h2><a name="4" href="#4">4. Conformance</a></h2>
<p><!--para 1 -->
In this International Standard, ''shall'' is to be interpreted as a requirement on an
implementation or on a program; conversely, ''shall not'' is to be interpreted as a
/* ... */
fesetround(FE_UPWARD);
/* ... */
- #endif</pre>
+ #endif
+</pre>
</small>
<p><small><a name="note4" href="#note4">4)</a> This implies that a conforming implementation reserves no identifiers other than those explicitly
implementation.
</small>
-<a name="5" href="#5"><h2>5. Environment</h2></a>
+<h2><a name="5" href="#5">5. Environment</a></h2>
<p><!--para 1 -->
An implementation translates C source files and executes C programs in two data-
processing-system environments, which will be called the translation environment and
<p><b> Forward references</b>: In this clause, only a few of many possible forward references
have been noted.
-<a name="5.1" href="#5.1"><h3>5.1 Conceptual models</h3></a>
+<h3><a name="5.1" href="#5.1">5.1 Conceptual models</a></h3>
-<a name="5.1.1" href="#5.1.1"><h4>5.1.1 Translation environment</h4></a>
+<h4><a name="5.1.1" href="#5.1.1">5.1.1 Translation environment</a></h4>
-<a name="5.1.1.1" href="#5.1.1.1"><h5>5.1.1.1 Program structure</h5></a>
+<h5><a name="5.1.1.1" href="#5.1.1.1">5.1.1.1 Program structure</a></h5>
<p><!--para 1 -->
A C program need not all be translated at the same time. The text of the program is kept
in units called source files, (or preprocessing files) in this International Standard. A
<p><b> Forward references</b>: linkages of identifiers (<a href="#6.2.2">6.2.2</a>), external definitions (<a href="#6.9">6.9</a>),
preprocessing directives (<a href="#6.10">6.10</a>).
-<a name="5.1.1.2" href="#5.1.1.2"><h5>5.1.1.2 Translation phases</h5></a>
+<h5><a name="5.1.1.2" href="#5.1.1.2">5.1.1.2 Translation phases</a></h5>
<p><!--para 1 -->
The precedence among the syntax rules of translation is specified by the following
phases.<sup><a href="#note6"><b>6)</b></a></sup>
character.
</small>
-<a name="5.1.1.3" href="#5.1.1.3"><h5>5.1.1.3 Diagnostics</h5></a>
+<h5><a name="5.1.1.3" href="#5.1.1.3">5.1.1.3 Diagnostics</a></h5>
<p><!--para 1 -->
A conforming implementation shall produce at least one diagnostic message (identified in
an implementation-defined manner) if a preprocessing translation unit or translation unit
EXAMPLE An implementation shall issue a diagnostic for the translation unit:
<pre>
char i;
- int i;</pre>
+ int i;
+</pre>
because in those cases where wording in this International Standard describes the behavior for a construct
as being both a constraint error and resulting in undefined behavior, the constraint error shall be diagnosed.
valid program is still correctly translated. It may also successfully translate an invalid program.
</small>
-<a name="5.1.2" href="#5.1.2"><h4>5.1.2 Execution environments</h4></a>
+<h4><a name="5.1.2" href="#5.1.2">5.1.2 Execution environments</a></h4>
<p><!--para 1 -->
Two execution environments are defined: freestanding and hosted. In both cases,
program startup occurs when a designated C function is called by the execution
environment.
<p><b> Forward references</b>: storage durations of objects (<a href="#6.2.4">6.2.4</a>), initialization (<a href="#6.7.9">6.7.9</a>).
-<a name="5.1.2.1" href="#5.1.2.1"><h5>5.1.2.1 Freestanding environment</h5></a>
+<h5><a name="5.1.2.1" href="#5.1.2.1">5.1.2.1 Freestanding environment</a></h5>
<p><!--para 1 -->
In a freestanding environment (in which C program execution may take place without any
benefit of an operating system), the name and type of the function called at program
The effect of program termination in a freestanding environment is implementation-
defined.
-<a name="5.1.2.2" href="#5.1.2.2"><h5>5.1.2.2 Hosted environment</h5></a>
+<h5><a name="5.1.2.2" href="#5.1.2.2">5.1.2.2 Hosted environment</a></h5>
<p><!--para 1 -->
A hosted environment need not be provided, but shall conform to the following
specifications if present.
<!--page 31 -->
-<a name="5.1.2.2.1" href="#5.1.2.2.1"><h5>5.1.2.2.1 Program startup</h5></a>
+<h5><a name="5.1.2.2.1" href="#5.1.2.2.1">5.1.2.2.1 Program startup</a></h5>
<p><!--para 1 -->
The function called at program startup is named main. The implementation declares no
prototype for this function. It shall be defined with a return type of int and with no
parameters:
<pre>
- int main(void) { /* ... */ }</pre>
+ int main(void) { /* ... */ }
+</pre>
or with two parameters (referred to here as argc and argv, though any names may be
used, as they are local to the function in which they are declared):
<pre>
- int main(int argc, char *argv[]) { /* ... */ }</pre>
+ int main(int argc, char *argv[]) { /* ... */ }
+</pre>
or equivalent;<sup><a href="#note10"><b>10)</b></a></sup> or in some other implementation-defined manner.
<p><!--para 2 -->
If they are declared, the parameters to the main function shall obey the following
char ** argv, and so on.
</small>
-<a name="5.1.2.2.2" href="#5.1.2.2.2"><h5>5.1.2.2.2 Program execution</h5></a>
+<h5><a name="5.1.2.2.2" href="#5.1.2.2.2">5.1.2.2.2 Program execution</a></h5>
<p><!--para 1 -->
In a hosted environment, a program may use all the functions, macros, type definitions,
and objects described in the library clause (clause 7).
<!--page 32 -->
-<a name="5.1.2.2.3" href="#5.1.2.2.3"><h5>5.1.2.2.3 Program termination</h5></a>
+<h5><a name="5.1.2.2.3" href="#5.1.2.2.3">5.1.2.2.3 Program termination</a></h5>
<p><!--para 1 -->
If the return type of the main function is a type compatible with int, a return from the
initial call to the main function is equivalent to calling the exit function with the value
will have ended in the former case, even where they would not have in the latter.
</small>
-<a name="5.1.2.3" href="#5.1.2.3"><h5>5.1.2.3 Program execution</h5></a>
+<h5><a name="5.1.2.3" href="#5.1.2.3">5.1.2.3 Program execution</a></h5>
<p><!--para 1 -->
The semantic descriptions in this International Standard describe the behavior of an
abstract machine in which issues of optimization are irrelevant.
<pre>
char c1, c2;
/* ... */
- c1 = c1 + c2;</pre>
+ c1 = c1 + c2;
+</pre>
the ''integer promotions'' require that the abstract machine promote the value of each variable to int size
and then add the two ints and truncate the sum. Provided the addition of two chars can be done without
overflow, or with overflow wrapping silently to produce the correct result, the actual execution need only
float f1, f2;
double d;
/* ... */
- f1 = f2 * d;</pre>
+ f1 = f2 * d;
+</pre>
the multiplication may be executed using single-precision arithmetic if the implementation can ascertain
that the result would be the same as if it were executed using double-precision arithmetic (for example, if d
were replaced by the constant 2.0, which has type double).
double d1, d2;
float f;
d1 = f = expression;
- d2 = (float) expression;</pre>
+ d2 = (float) expression;
+</pre>
the values assigned to d1 and d2 are required to have been converted to float.
<p><!--para 14 -->
x = (x * y) * z; // not equivalent to x *= y * z;
z = (x - y) + y ; // not equivalent to z = x;
z = x + x * y; // not equivalent to z = x * (1.0 + y);
- y = x / 5.0; // not equivalent to y = x * 0.2;</pre>
+ y = x / 5.0; // not equivalent to y = x * 0.2;
+</pre>
<p><!--para 15 -->
EXAMPLE 6 To illustrate the grouping behavior of expressions, in the following fragment
<pre>
int a, b;
/* ... */
- a = a + 32760 + b + 5;</pre>
+ a = a + 32760 + b + 5;
+</pre>
the expression statement behaves exactly the same as
<pre>
- a = (((a + 32760) + b) + 5);</pre>
+ a = (((a + 32760) + b) + 5);
+</pre>
due to the associativity and precedence of these operators. Thus, the result of the sum (a + 32760) is
next added to b, and that result is then added to 5 which results in the value assigned to a. On a machine in
which overflows produce an explicit trap and in which the range of values representable by an int is
[-32768, +32767], the implementation cannot rewrite this expression as
<pre>
- a = ((a + b) + 32765);</pre>
+ a = ((a + b) + 32765);
+</pre>
since if the values for a and b were, respectively, -32754 and -15, the sum a + b would produce a trap
while the original expression would not; nor can the expression be rewritten either as
<!--page 35 -->
<pre>
- a = ((a + 32765) + b);</pre>
+ a = ((a + 32765) + b);
+</pre>
or
<pre>
- a = (a + (b + 32765));</pre>
+ a = (a + (b + 32765));
+</pre>
since the values for a and b might have been, respectively, 4 and -8 or -17 and 12. However, on a machine
in which overflow silently generates some value and where positive and negative overflows cancel, the
above expression statement can be rewritten by the implementation in any of the above ways because the
int sum;
char *p;
/* ... */
- sum = sum * 10 - '0' + (*p++ = getchar());</pre>
+ sum = sum * 10 - '0' + (*p++ = getchar());
+</pre>
the expression statement is grouped as if it were written as
<pre>
- sum = (((sum * 10) - '0') + ((*(p++)) = (getchar())));</pre>
+ sum = (((sum * 10) - '0') + ((*(p++)) = (getchar())));
+</pre>
but the actual increment of p can occur at any time between the previous sequence point and the next
sequence point (the ;), and the call to getchar can occur at any point prior to the need of its returned
value.
cannot interleave, but can be executed in any order.
</small>
-<a name="5.1.2.4" href="#5.1.2.4"><h5>5.1.2.4 Multi-threaded executions and data races</h5></a>
+<h5><a name="5.1.2.4" href="#5.1.2.4">5.1.2.4 Multi-threaded executions and data races</a></h5>
<p><!--para 1 -->
Under a hosted implementation, a program can have more than one thread of execution
(or thread) running concurrently. The execution of each thread proceeds as defined by
release/consume in place of release/acquire.
</small>
-<a name="5.2" href="#5.2"><h3>5.2 Environmental considerations</h3></a>
+<h3><a name="5.2" href="#5.2">5.2 Environmental considerations</a></h3>
-<a name="5.2.1" href="#5.2.1"><h4>5.2.1 Character sets</h4></a>
+<h4><a name="5.2.1" href="#5.2.1">5.2.1 Character sets</a></h4>
<p><!--para 1 -->
Two sets of characters and their associated collating sequences shall be defined: the set in
which source files are written (the source character set), and the set interpreted in the
members: the 26 uppercase letters of the Latin alphabet
<pre>
A B C D E F G H I J K L M
- N O P Q R S T U V W X Y Z</pre>
+ N O P Q R S T U V W X Y Z
+</pre>
the 26 lowercase letters of the Latin alphabet
<pre>
a b c d e f g h i j k l m
- n o p q r s t u v w x y z</pre>
+ n o p q r s t u v w x y z
+</pre>
the 10 decimal digits
<pre>
- 0 1 2 3 4 5 6 7 8 9</pre>
+ 0 1 2 3 4 5 6 7 8 9
+</pre>
the following 29 graphic characters
<pre>
! " # % & ' ( ) * + , - . / :
- ; < = > ? [ \ ] ^ _ { | } ~</pre>
+ ; < = > ? [ \ ] ^ _ { | } ~
+</pre>
the space character, and control characters representing horizontal tab, vertical tab, and
form feed. The representation of each member of the source and execution basic
character sets shall fit in a byte. In both the source and execution basic character sets, the
<p><b> Forward references</b>: universal character names (<a href="#6.4.3">6.4.3</a>), character constants (<a href="#6.4.4.4">6.4.4.4</a>),
preprocessing directives (<a href="#6.10">6.10</a>), string literals (<a href="#6.4.5">6.4.5</a>), comments (<a href="#6.4.9">6.4.9</a>), string (<a href="#7.1.1">7.1.1</a>).
-<a name="5.2.1.1" href="#5.2.1.1"><h5>5.2.1.1 Trigraph sequences</h5></a>
+<h5><a name="5.2.1.1" href="#5.2.1.1">5.2.1.1 Trigraph sequences</a></h5>
<p><!--para 1 -->
Before any other processing takes place, each occurrence of one of the following
sequences of three characters (called trigraph sequences<sup><a href="#note17"><b>17)</b></a></sup>) is replaced with the
<pre>
??= # ??) ] ??! |
??( [ ??' ^ ??> }
- ??/ \ ??< { ??- ~</pre>
+ ??/ \ ??< { ??- ~
+</pre>
No other trigraph sequences exist. Each ? that does not begin one of the trigraphs listed
above is not changed.
<p><!--para 2 -->
EXAMPLE 1
<pre>
- ??=define arraycheck(a, b) a??(b??) ??!??! b??(a??)</pre>
+ ??=define arraycheck(a, b) a??(b??) ??!??! b??(a??)
+</pre>
becomes
<pre>
- #define arraycheck(a, b) a[b] || b[a]</pre>
+ #define arraycheck(a, b) a[b] || b[a]
+</pre>
<p><!--para 3 -->
EXAMPLE 2 The following source line
<pre>
- printf("Eh???/n");</pre>
+ printf("Eh???/n");
+</pre>
becomes (after replacement of the trigraph sequence ??/)
<pre>
- printf("Eh?\n");</pre>
+ printf("Eh?\n");
+</pre>
<h6>footnotes</h6>
described in ISO/IEC 646, which is a subset of the seven-bit US ASCII code set.
</small>
-<a name="5.2.1.2" href="#5.2.1.2"><h5>5.2.1.2 Multibyte characters</h5></a>
+<h5><a name="5.2.1.2" href="#5.2.1.2">5.2.1.2 Multibyte characters</a></h5>
<p><!--para 1 -->
The source character set may contain multibyte characters, used to represent members of
the extended character set. The execution character set may also contain multibyte
of a sequence of valid multibyte characters.
</ul>
-<a name="5.2.2" href="#5.2.2"><h4>5.2.2 Character display semantics</h4></a>
+<h4><a name="5.2.2" href="#5.2.2">5.2.2 Character display semantics</a></h4>
<p><!--para 1 -->
The active position is that location on a display device where the next character output by
the fputc function would appear. The intent of writing a printing character (as defined
\b (backspace) Moves the active position to the previous position on the current line. If
<pre>
the active position is at the initial position of a line, the behavior of the display
- device is unspecified.</pre>
+ device is unspecified.
+</pre>
\f ( form feed) Moves the active position to the initial position at the start of the next
<pre>
- logical page.</pre>
+ logical page.
+</pre>
\n (new line) Moves the active position to the initial position of the next line.
\r (carriage return) Moves the active position to the initial position of the current line.
\t (horizontal tab) Moves the active position to the next horizontal tabulation position
<pre>
on the current line. If the active position is at or past the last defined horizontal
- tabulation position, the behavior of the display device is unspecified.</pre>
+ tabulation position, the behavior of the display device is unspecified.
+</pre>
\v (vertical tab) Moves the active position to the initial position of the next vertical
<!--page 43 -->
-<p><!--para 3 -->
<pre>
tabulation position. If the active position is at or past the last defined vertical
- tabulation position, the behavior of the display device is unspecified.</pre>
+ tabulation position, the behavior of the display device is unspecified.
+</pre>
+<p><!--para 3 -->
Each of these escape sequences shall produce a unique implementation-defined value
which can be stored in a single char object. The external representations in a text file
need not be identical to the internal representations, and are outside the scope of this
International Standard.
<p><b> Forward references</b>: the isprint function (<a href="#7.4.1.8">7.4.1.8</a>), the fputc function (<a href="#7.21.7.3">7.21.7.3</a>).
-<a name="5.2.3" href="#5.2.3"><h4>5.2.3 Signals and interrupts</h4></a>
+<h4><a name="5.2.3" href="#5.2.3">5.2.3 Signals and interrupts</a></h4>
<p><!--para 1 -->
Functions shall be implemented such that they may be interrupted at any time by a signal,
or may be called by a signal handler, or both, with no alteration to earlier, but still active,
image (the instructions that compose the executable representation of a function) on a
per-invocation basis.
-<a name="5.2.4" href="#5.2.4"><h4>5.2.4 Environmental limits</h4></a>
+<h4><a name="5.2.4" href="#5.2.4">5.2.4 Environmental limits</a></h4>
<p><!--para 1 -->
Both the translation and execution environments constrain the implementation of
language translators and libraries. The following summarizes the language-related
environmental limits on a conforming implementation; the library-related limits are
discussed in clause 7.
-<a name="5.2.4.1" href="#5.2.4.1"><h5>5.2.4.1 Translation limits</h5></a>
+<h5><a name="5.2.4.1" href="#5.2.4.1">5.2.4.1 Translation limits</a></h5>
<p><!--para 1 -->
The implementation shall be able to translate and execute at least one program that
contains at least one instance of every one of the following limits:<sup><a href="#note18"><b>18)</b></a></sup>
<pre>
universal character name specifying a short identifier of 00010000 or more is
considered 10 characters, and each extended source character is considered the same
- number of characters as the corresponding universal character name, if any)<sup><a href="#note19"><b>19)</b></a></sup></pre>
+ number of characters as the corresponding universal character name, if any)<sup><a href="#note19"><b>19)</b></a></sup>
+</pre>
<li> 4095 external identifiers in one translation unit
<li> 511 identifiers with block scope declared in one block
<li> 4095 macro identifiers simultaneously defined in one preprocessing translation unit
<p><small><a name="note19" href="#note19">19)</a> See ''future language directions'' (<a href="#6.11.3">6.11.3</a>).
</small>
-<a name="5.2.4.2" href="#5.2.4.2"><h5>5.2.4.2 Numerical limits</h5></a>
+<h5><a name="5.2.4.2" href="#5.2.4.2">5.2.4.2 Numerical limits</a></h5>
<p><!--para 1 -->
An implementation is required to document all the limits specified in this subclause,
which are specified in the headers <a href="#7.10"><limits.h></a> and <a href="#7.7"><float.h></a>. Additional limits are
specified in <a href="#7.20"><stdint.h></a>.
<p><b> Forward references</b>: integer types <a href="#7.20"><stdint.h></a> (<a href="#7.20">7.20</a>).
-<a name="5.2.4.2.1" href="#5.2.4.2.1"><h5>5.2.4.2.1 Sizes of integer types <limits.h></h5></a>
+<h5><a name="5.2.4.2.1" href="#5.2.4.2.1">5.2.4.2.1 Sizes of integer types <limits.h></a></h5>
<p><!--para 1 -->
The values given below shall be replaced by constant expressions suitable for use in #if
preprocessing directives. Moreover, except for CHAR_BIT and MB_LEN_MAX, the
<p><small><a name="note20" href="#note20">20)</a> See <a href="#6.2.5">6.2.5</a>.
</small>
-<a name="5.2.4.2.2" href="#5.2.4.2.2"><h5>5.2.4.2.2 Characteristics of floating types <float.h></h5></a>
+<h5><a name="5.2.4.2.2" href="#5.2.4.2.2">5.2.4.2.2 Characteristics of floating types <float.h></a></h5>
<p><!--para 1 -->
The characteristics of floating types are defined in terms of a model that describes a
representation of floating-point numbers and values that provide information about an
implementation's floating-point arithmetic.<sup><a href="#note21"><b>21)</b></a></sup> The following parameters are used to
define the model for each floating-point type:
-<p><!--para 2 -->
<pre>
s sign ((+-)1)
b base or radix of exponent representation (an integer > 1)
e exponent (an integer between a minimum emin and a maximum emax )
p precision (the number of base-b digits in the significand)
- fk nonnegative integers less than b (the significand digits)</pre>
+ fk nonnegative integers less than b (the significand digits)
+</pre>
+<p><!--para 2 -->
A floating-point number (x) is defined by the following model:
<pre>
p
x = sb e (Sum) f k b-k ,
k=1
- emin <= e <= emax</pre>
+ emin <= e <= emax
+</pre>
<p><!--para 3 -->
In addition to normalized floating-point numbers ( f 1 > 0 if x != 0), floating types may be
0 toward zero
1 to nearest
2 toward positive infinity
- 3 toward negative infinity</pre>
+ 3 toward negative infinity
+</pre>
All other values for FLT_ROUNDS characterize implementation-defined rounding
behavior.
operations and constants to the range and precision of the long double
type;
2 evaluate all operations and constants to the range and precision of the
- long double type.</pre>
+ long double type.
+</pre>
All other negative values for FLT_EVAL_METHOD characterize implementation-defined
behavior.
<p><!--para 10 -->
The presence or absence of subnormal numbers is characterized by the implementation-
defined values of FLT_HAS_SUBNORM, DBL_HAS_SUBNORM, and
LDBL_HAS_SUBNORM:
-<p><!--para 11 -->
<pre>
-1 indeterminable<sup><a href="#note25"><b>25)</b></a></sup>
0 absent<sup><a href="#note26"><b>26)</b></a></sup> (type does not support subnormal numbers)
- 1 present (type does support subnormal numbers)</pre>
+ 1 present (type does support subnormal numbers)
+</pre>
+<p><!--para 11 -->
The values given in the following list shall be replaced by constant expressions with
implementation-defined values that are greater or equal in magnitude (absolute value) to
those shown, with the same sign:
<pre>
{ p log10 b if b is a power of 10
{
- { [^1 + p log10 b^] otherwise</pre>
+ { [^1 + p log10 b^] otherwise
+</pre>
FLT_DECIMAL_DIG 6
DBL_DECIMAL_DIG 10
LDBL_DECIMAL_DIG 10
<pre>
{ pmax log10 b if b is a power of 10
{
- { [^1 + pmax log10 b^] otherwise</pre>
+ { [^1 + pmax log10 b^] otherwise
+</pre>
DECIMAL_DIG 10
<li> number of decimal digits, q, such that any floating-point number with q decimal digits
can be rounded into a floating-point number with p radix b digits and back again
<pre>
{ p log10 b if b is a power of 10
{
- { [_( p - 1) log10 b_] otherwise</pre>
+ { [_( p - 1) log10 b_] otherwise
+</pre>
FLT_DIG 6
DBL_DIG 10
LDBL_DIG 10
<li> minimum negative integer such that 10 raised to that power is in the range of
normalized floating-point numbers, [^log10 b emin -1 ^]
<pre>
- [ ]</pre>
+ [ ]
+</pre>
FLT_MIN_10_EXP -37
DBL_MIN_10_EXP -37
LDBL_MIN_10_EXP -37
<pre>
FLT_MAX_EXP
DBL_MAX_EXP
- LDBL_MAX_EXP</pre>
+ LDBL_MAX_EXP
+</pre>
<li> maximum integer such that 10 raised to that power is in the range of representable
finite floating-point numbers, [_log10 ((1 - b- p )b emax )_]
-</ul>
-<p><!--para 12 -->
<pre>
FLT_MAX_10_EXP +37
DBL_MAX_10_EXP +37
- LDBL_MAX_10_EXP +37</pre>
+ LDBL_MAX_10_EXP +37
+</pre>
+</ul>
+<p><!--para 12 -->
The values given in the following list shall be replaced by constant expressions with
implementation-defined values that are greater than or equal to those shown:
<ul>
<li> maximum representable finite floating-point number, (1 - b- p )b emax
-</ul>
-<p><!--para 13 -->
<pre>
FLT_MAX 1E+37
DBL_MAX 1E+37
- LDBL_MAX 1E+37</pre>
+ LDBL_MAX 1E+37
+</pre>
+</ul>
+<p><!--para 13 -->
The values given in the following list shall be replaced by constant expressions with
implementation-defined (positive) values that are less than or equal to those shown:
<ul>
<pre>
FLT_EPSILON 1E-5
DBL_EPSILON 1E-9
- LDBL_EPSILON 1E-9</pre>
+ LDBL_EPSILON 1E-9
+</pre>
<li> minimum normalized positive floating-point number, b emin -1
<!--page 51 -->
<pre>
FLT_MIN 1E-37
DBL_MIN 1E-37
- LDBL_MIN 1E-37</pre>
+ LDBL_MIN 1E-37
+</pre>
<li> minimum positive floating-point number<sup><a href="#note27"><b>27)</b></a></sup>
FLT_TRUE_MIN 1E-37
DBL_TRUE_MIN 1E-37
LDBL_TRUE_MIN 1E-37
</ul>
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 14 -->
Conversion from (at least) double to decimal with DECIMAL_DIG digits and back
should be the identity function.
6
x = s16e (Sum) f k 16-k ,
k=1
- -31 <= e <= +32</pre>
+ -31 <= e <= +32
+</pre>
<pre>
FLT_RADIX 16
FLT_MIN_10_EXP -38
FLT_MAX_EXP +32
FLT_MAX 3.40282347E+38F
- FLT_MAX_10_EXP +38</pre>
+ FLT_MAX_10_EXP +38
+</pre>
<p><!--para 16 -->
EXAMPLE 2 The following describes floating-point representations that also meet the requirements for
24
x f = s2e (Sum) f k 2-k ,
k=1
- -125 <= e <= +128</pre>
+ -125 <= e <= +128
+</pre>
<pre>
53
x d = s2e (Sum) f k 2-k ,
k=1
- -1021 <= e <= +1024</pre>
+ -1021 <= e <= +1024
+</pre>
<pre>
FLT_RADIX 2
FLT_MANT_DIG 24
FLT_EPSILON 1.19209290E-07F // decimal constant
FLT_EPSILON 0X1P-23F // hex constant
- FLT_DECIMAL_DIG 9</pre>
+ FLT_DECIMAL_DIG 9
+</pre>
<!--page 52 -->
DBL_MAX_EXP +1024
DBL_MAX 1.7976931348623157E+308 // decimal constant
DBL_MAX 0X1.fffffffffffffP1023 // hex constant
- DBL_MAX_10_EXP +308</pre>
+ DBL_MAX_10_EXP +308
+</pre>
If a type wider than double were supported, then DECIMAL_DIG would be greater than 17. For
example, if the widest type were to use the minimal-width IEC 60559 double-extended format (64 bits of
precision), then DECIMAL_DIG would be 21.
limits are one less than shown here.
</small>
-<a name="6" href="#6"><h2>6. Language</h2></a>
+<h2><a name="6" href="#6">6. Language</a></h2>
-<a name="6.1" href="#6.1"><h3>6.1 Notation</h3></a>
+<h3><a name="6.1" href="#6.1">6.1 Notation</a></h3>
<p><!--para 1 -->
In the syntax notation used in this clause, syntactic categories (nonterminals) are
indicated by italic type, and literal words and character set members (terminals) by bold
definitions are listed on separate lines, except when prefaced by the words ''one of''. An
optional symbol is indicated by the subscript ''opt'', so that
<pre>
- { expressionopt }</pre>
+ { expression<sub>opt</sub> }
+</pre>
indicates an optional expression enclosed in braces.
<p><!--para 2 -->
When syntactic categories are referred to in the main text, they are not italicized and
<p><!--para 3 -->
A summary of the language syntax is given in <a href="#A">annex A</a>.
-<a name="6.2" href="#6.2"><h3>6.2 Concepts</h3></a>
+<h3><a name="6.2" href="#6.2">6.2 Concepts</a></h3>
-<a name="6.2.1" href="#6.2.1"><h4>6.2.1 Scopes of identifiers</h4></a>
+<h4><a name="6.2.1" href="#6.2.1">6.2.1 Scopes of identifiers</a></h4>
<p><!--para 1 -->
An identifier can denote an object; a function; a tag or a member of a structure, union, or
enumeration; a typedef name; a label name; a macro name; or a macro parameter. The
(<a href="#6.9.1">6.9.1</a>), identifiers (<a href="#6.4.2">6.4.2</a>), macro replacement (<a href="#6.10.3">6.10.3</a>), name spaces of identifiers (<a href="#6.2.3">6.2.3</a>),
source file inclusion (<a href="#6.10.2">6.10.2</a>), statements (<a href="#6.8">6.8</a>).
-<a name="6.2.2" href="#6.2.2"><h4>6.2.2 Linkages of identifiers</h4></a>
+<h4><a name="6.2.2" href="#6.2.2">6.2.2 Linkages of identifiers</a></h4>
<p><!--para 1 -->
An identifier declared in different scopes or in the same scope more than once can be
made to refer to the same object or function by a process called linkage.<sup><a href="#note29"><b>29)</b></a></sup> There are
<p><small><a name="note31" href="#note31">31)</a> As specified in <a href="#6.2.1">6.2.1</a>, the later declaration might hide the prior declaration.
</small>
-<a name="6.2.3" href="#6.2.3"><h4>6.2.3 Name spaces of identifiers</h4></a>
+<h4><a name="6.2.3" href="#6.2.3">6.2.3 Name spaces of identifiers</a></h4>
<p><!--para 1 -->
If more than one declaration of a particular identifier is visible at any point in a
translation unit, the syntactic context disambiguates uses that refer to different entities.
<p><small><a name="note32" href="#note32">32)</a> There is only one name space for tags even though three are possible.
</small>
-<a name="6.2.4" href="#6.2.4"><h4>6.2.4 Storage durations of objects</h4></a>
+<h4><a name="6.2.4" href="#6.2.4">6.2.4 Storage durations of objects</a></h4>
<p><!--para 1 -->
An object has a storage duration that determines its lifetime. There are four storage
durations: static, thread, automatic, and allocated. Allocated storage is described in
<p><small><a name="note36" href="#note36">36)</a> The address of such an object is taken implicitly when an array member is accessed.
</small>
-<a name="6.2.5" href="#6.2.5"><h4>6.2.5 Types</h4></a>
+<h4><a name="6.2.5" href="#6.2.5">6.2.5 Types</a></h4>
<p><!--para 1 -->
The meaning of a value stored in an object or returned by a function is determined by the
type of the expression used to access it. (An identifier declared to be an object is the
include the atomic types.
<p><!--para 28 -->
A pointer to void shall have the same representation and alignment requirements as a
- pointer to a character type.48) Similarly, pointers to qualified or unqualified versions of
+ pointer to a character type.<sup><a href="#note48"><b>48)</b></a></sup> Similarly, pointers to qualified or unqualified versions of
compatible types shall have the same representation and alignment requirements. All
pointers to structure types shall have the same representation and alignment requirements
as each other. All pointers to union types shall have the same representation and
arguments to functions, return values from functions, and members of unions.
</small>
-<a name="6.2.6" href="#6.2.6"><h4>6.2.6 Representations of types</h4></a>
+<h4><a name="6.2.6" href="#6.2.6">6.2.6 Representations of types</a></h4>
-<a name="6.2.6.1" href="#6.2.6.1"><h5>6.2.6.1 General</h5></a>
+<h5><a name="6.2.6.1" href="#6.2.6.1">6.2.6.1 General</a></h5>
<p><!--para 1 -->
The representations of all types are unspecified except as stated in this subclause.
<p><!--para 2 -->
<pre>
CHAR_BIT
- - 1.</pre>
+ - 1.
+</pre>
</small>
<p><small><a name="note50" href="#note50">50)</a> Thus, an automatic variable can be initialized to a trap representation without causing undefined
behavior, but the value of the variable cannot be used until a proper value is stored in it.
on values of type T may distinguish between them.
</small>
-<a name="6.2.6.2" href="#6.2.6.2"><h5>6.2.6.2 Integer types</h5></a>
+<h5><a name="6.2.6.2" href="#6.2.6.2">6.2.6.2 Integer types</a></h5>
<p><!--para 1 -->
For unsigned integer types other than unsigned char, the bits of the object
representation shall be divided into two groups: value bits and padding bits (there need
bits.
</small>
-<a name="6.2.7" href="#6.2.7"><h4>6.2.7 Compatible type and composite type</h4></a>
+<h4><a name="6.2.7" href="#6.2.7">6.2.7 Compatible type and composite type</a></h4>
<p><!--para 1 -->
Two types have compatible type if their types are the same. Additional rules for
determining whether two types are compatible are described in <a href="#6.7.2">6.7.2</a> for type specifiers,
EXAMPLE Given the following two file scope declarations:
<pre>
int f(int (*)(), double (*)[3]);
- int f(int (*)(char *), double (*)[]);</pre>
+ int f(int (*)(char *), double (*)[]);
+</pre>
The resulting composite type for the function is:
<pre>
- int f(int (*)(char *), double (*)[3]);</pre>
+ int f(int (*)(char *), double (*)[3]);
+</pre>
<h6>footnotes</h6>
<p><small><a name="note56" href="#note56">56)</a> As specified in <a href="#6.2.1">6.2.1</a>, the later declaration might hide the prior declaration.
</small>
-<a name="6.2.8" href="#6.2.8"><h4>6.2.8 Alignment of objects</h4></a>
+<h4><a name="6.2.8" href="#6.2.8">6.2.8 Alignment of objects</a></h4>
<p><!--para 1 -->
Complete object types have alignment requirements which place restrictions on the
addresses at which objects of that type may be allocated. An alignment is an
alignment has been applied.
</small>
-<a name="6.3" href="#6.3"><h3>6.3 Conversions</h3></a>
+<h3><a name="6.3" href="#6.3">6.3 Conversions</a></h3>
<p><!--para 1 -->
Several operators convert operand values from one type to another automatically. This
subclause specifies the result required from such an implicit conversion, as well as those
representation.
<p><b> Forward references</b>: cast operators (<a href="#6.5.4">6.5.4</a>).
-<a name="6.3.1" href="#6.3.1"><h4>6.3.1 Arithmetic operands</h4></a>
+<h4><a name="6.3.1" href="#6.3.1">6.3.1 Arithmetic operands</a></h4>
-<a name="6.3.1.1" href="#6.3.1.1"><h5>6.3.1.1 Boolean, characters, and integers</h5></a>
+<h5><a name="6.3.1.1" href="#6.3.1.1">6.3.1.1 Boolean, characters, and integers</a></h5>
<p><!--para 1 -->
Every integer type has an integer conversion rank defined as follows:
<ul>
shift operators, as specified by their respective subclauses.
</small>
-<a name="6.3.1.2" href="#6.3.1.2"><h5>6.3.1.2 Boolean type</h5></a>
+<h5><a name="6.3.1.2" href="#6.3.1.2">6.3.1.2 Boolean type</a></h5>
<p><!--para 1 -->
When any scalar value is converted to _Bool, the result is 0 if the value compares equal
to 0; otherwise, the result is 1.<sup><a href="#note59"><b>59)</b></a></sup>
<p><small><a name="note59" href="#note59">59)</a> NaNs do not compare equal to 0 and thus convert to 1.
</small>
-<a name="6.3.1.3" href="#6.3.1.3"><h5>6.3.1.3 Signed and unsigned integers</h5></a>
+<h5><a name="6.3.1.3" href="#6.3.1.3">6.3.1.3 Signed and unsigned integers</a></h5>
<p><!--para 1 -->
When a value with integer type is converted to another integer type other than _Bool, if
the value can be represented by the new type, it is unchanged.
<p><small><a name="note60" href="#note60">60)</a> The rules describe arithmetic on the mathematical value, not the value of a given type of expression.
</small>
-<a name="6.3.1.4" href="#6.3.1.4"><h5>6.3.1.4 Real floating and integer</h5></a>
+<h5><a name="6.3.1.4" href="#6.3.1.4">6.3.1.4 Real floating and integer</a></h5>
<p><!--para 1 -->
When a finite value of real floating type is converted to an integer type other than _Bool,
the fractional part is discarded (i.e., the value is truncated toward zero). If the value of
range of portable real floating values is (-1, Utype_MAX+1).
</small>
-<a name="6.3.1.5" href="#6.3.1.5"><h5>6.3.1.5 Real floating types</h5></a>
+<h5><a name="6.3.1.5" href="#6.3.1.5">6.3.1.5 Real floating types</a></h5>
<p><!--para 1 -->
When a value of real floating type is converted to a real floating type, if the value being
converted can be represented exactly in the new type, it is unchanged. If the value being
conversions (<a href="#6.3.1.8">6.3.1.8</a>, <a href="#6.8.6.4">6.8.6.4</a>) may be represented in greater precision and range than that
required by the new type.
-<a name="6.3.1.6" href="#6.3.1.6"><h5>6.3.1.6 Complex types</h5></a>
+<h5><a name="6.3.1.6" href="#6.3.1.6">6.3.1.6 Complex types</a></h5>
<p><!--para 1 -->
When a value of complex type is converted to another complex type, both the real and
imaginary parts follow the conversion rules for the corresponding real types.
-<a name="6.3.1.7" href="#6.3.1.7"><h5>6.3.1.7 Real and complex</h5></a>
+<h5><a name="6.3.1.7" href="#6.3.1.7">6.3.1.7 Real and complex</a></h5>
<p><!--para 1 -->
When a value of real type is converted to a complex type, the real part of the complex
result value is determined by the rules of conversion to the corresponding real type and
complex value is discarded and the value of the real part is converted according to the
conversion rules for the corresponding real type.
-<a name="6.3.1.8" href="#6.3.1.8"><h5>6.3.1.8 Usual arithmetic conversions</h5></a>
+<h5><a name="6.3.1.8" href="#6.3.1.8">6.3.1.8 Usual arithmetic conversions</a></h5>
<p><!--para 1 -->
Many operators that expect operands of arithmetic type cause conversions and yield result
types in a similar way. The purpose is to determine a common real type for the operands
the result, whose type domain is the type domain of the operands if they are the same,
and complex otherwise. This pattern is called the usual arithmetic conversions:
<!--page 71 -->
-<p><!--para 2 -->
<pre>
First, if the corresponding real type of either operand is long double, the other
operand is converted, without change of type domain, to a type whose
the operand with unsigned integer type is converted to the type of the
operand with signed integer type.
Otherwise, both operands are converted to the unsigned integer type
- corresponding to the type of the operand with signed integer type.</pre>
+ corresponding to the type of the operand with signed integer type.
+</pre>
+<p><!--para 2 -->
The values of floating operands and of the results of floating expressions may be
represented in greater precision and range than that required by the type; the types are not
changed thereby.<sup><a href="#note63"><b>63)</b></a></sup>
<p><small><a name="note63" href="#note63">63)</a> The cast and assignment operators are still required to remove extra range and precision.
</small>
-<a name="6.3.2" href="#6.3.2"><h4>6.3.2 Other operands</h4></a>
+<h4><a name="6.3.2" href="#6.3.2">6.3.2 Other operands</a></h4>
-<a name="6.3.2.1" href="#6.3.2.1"><h5>6.3.2.1 Lvalues, arrays, and function designators</h5></a>
+<h5><a name="6.3.2.1" href="#6.3.2.1">6.3.2.1 Lvalues, arrays, and function designators</a></h5>
<p><!--para 1 -->
An lvalue is an expression (with an object type other than void) that potentially
designates an object;<sup><a href="#note64"><b>64)</b></a></sup> if an lvalue does not designate an object when it is evaluated, the
designator and violates the constraint in <a href="#6.5.3.4">6.5.3.4</a>.
</small>
-<a name="6.3.2.2" href="#6.3.2.2"><h5>6.3.2.2 void</h5></a>
+<h5><a name="6.3.2.2" href="#6.3.2.2">6.3.2.2 void</a></h5>
<p><!--para 1 -->
The (nonexistent) value of a void expression (an expression that has type void) shall not
be used in any way, and implicit or explicit conversions (except to void) shall not be
expression, its value or designator is discarded. (A void expression is evaluated for its
side effects.)
-<a name="6.3.2.3" href="#6.3.2.3"><h5>6.3.2.3 Pointers</h5></a>
+<h5><a name="6.3.2.3" href="#6.3.2.3">6.3.2.3 Pointers</a></h5>
<p><!--para 1 -->
A pointer to void may be converted to or from a pointer to any object type. A pointer to
any object type may be converted to a pointer to void and back again; the result shall
correctly aligned for a pointer to type C.
</small>
-<a name="6.4" href="#6.4"><h3>6.4 Lexical elements</h3></a>
+<h3><a name="6.4" href="#6.4">6.4 Lexical elements</a></h3>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
character-constant
string-literal
punctuator
- each non-white-space character that cannot be one of the above</pre>
+ each non-white-space character that cannot be one of the above
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each preprocessing token that is converted to a token shall have the lexical form of a
occur in source files.
</small>
-<a name="6.4.1" href="#6.4.1"><h4>6.4.1 Keywords</h4></a>
+<h4><a name="6.4.1" href="#6.4.1">6.4.1 Keywords</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
enum static _Noreturn
extern struct _Static_assert
float switch _Thread_local
- for typedef</pre>
+ for typedef
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
The above tokens (case sensitive) are reserved (in translation phases 7 and 8) for use as
<p><small><a name="note70" href="#note70">70)</a> One possible specification for imaginary types appears in <a href="#G">annex G</a>.
</small>
-<a name="6.4.2" href="#6.4.2"><h4>6.4.2 Identifiers</h4></a>
+<h4><a name="6.4.2" href="#6.4.2">6.4.2 Identifiers</a></h4>
-<a name="6.4.2.1" href="#6.4.2.1"><h5>6.4.2.1 General</h5></a>
+<h5><a name="6.4.2.1" href="#6.4.2.1">6.4.2.1 General</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
digit: one of
- 0 1 2 3 4 5 6 7 8 9</pre>
+ 0 1 2 3 4 5 6 7 8 9
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
An identifier is a sequence of nondigit characters (including the underscore _, the
When preprocessing tokens are converted to tokens during translation phase 7, if a
preprocessing token could be converted to either a keyword or an identifier, it is converted
to a keyword.
- Implementation limits
+<h6>Implementation limits</h6>
<p><!--para 5 -->
As discussed in <a href="#5.2.4.1">5.2.4.1</a>, an implementation may limit the number of significant initial
characters in an identifier; the limit for an external name (an identifier that has external
Extended characters may produce a long external identifier.
</small>
-<a name="6.4.2.2" href="#6.4.2.2"><h5>6.4.2.2 Predefined identifiers</h5></a>
+<h5><a name="6.4.2.2" href="#6.4.2.2">6.4.2.2 Predefined identifiers</a></h5>
<h6>Semantics</h6>
<p><!--para 1 -->
The identifier __func__ shall be implicitly declared by the translator as if,
immediately following the opening brace of each function definition, the declaration
<pre>
- static const char __func__[] = "function-name";</pre>
+ static const char __func__[] = "function-name";
+</pre>
appeared, where function-name is the name of the lexically-enclosing function.<sup><a href="#note72"><b>72)</b></a></sup>
<p><!--para 2 -->
This name is encoded as if the implicit declaration had been written in the source
{
printf("%s\n", __func__);
/* ... */
- }</pre>
+ }
+</pre>
Each time the function is called, it will print to the standard output stream:
<pre>
- myfunc</pre>
+ myfunc
+</pre>
<p><b> Forward references</b>: function definitions (<a href="#6.9.1">6.9.1</a>).
identifier is explicitly declared using the name __func__, the behavior is undefined.
</small>
-<a name="6.4.3" href="#6.4.3"><h4>6.4.3 Universal character names</h4></a>
+<h4><a name="6.4.3" href="#6.4.3">6.4.3 Universal character names</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
\U hex-quad hex-quad
hex-quad:
hexadecimal-digit hexadecimal-digit
- hexadecimal-digit hexadecimal-digit</pre>
+ hexadecimal-digit hexadecimal-digit
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
A universal character name shall not specify a character whose short identifier is less than
<p><small><a name="note74" href="#note74">74)</a> Short identifiers for characters were first specified in ISO/IEC 10646-1/AMD9:1997.
</small>
-<a name="6.4.4" href="#6.4.4"><h4>6.4.4 Constants</h4></a>
+<h4><a name="6.4.4" href="#6.4.4">6.4.4 Constants</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
integer-constant
floating-constant
enumeration-constant
- character-constant</pre>
+ character-constant
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each constant shall have a type and the value of a constant shall be in the range of
<p><!--para 3 -->
Each constant has a type, determined by its form and value, as detailed later.
-<a name="6.4.4.1" href="#6.4.4.1"><h5>6.4.4.1 Integer constants</h5></a>
+<h5><a name="6.4.4.1" href="#6.4.4.1">6.4.4.1 Integer constants</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<!--page 81 -->
<pre>
integer-constant:
- decimal-constant integer-suffixopt
- octal-constant integer-suffixopt
- hexadecimal-constant integer-suffixopt
+ decimal-constant integer-suffix<sub>opt</sub>
+ octal-constant integer-suffix<sub>opt</sub>
+ hexadecimal-constant integer-suffix<sub>opt</sub>
decimal-constant:
nonzero-digit
decimal-constant digit
a b c d e f
A B C D E F
integer-suffix:
- unsigned-suffix long-suffixopt
+ unsigned-suffix long-suffix<sub>opt</sub>
unsigned-suffix long-long-suffix
- long-suffix unsigned-suffixopt
- long-long-suffix unsigned-suffixopt
+ long-suffix unsigned-suffix<sub>opt</sub>
+ long-long-suffix unsigned-suffix<sub>opt</sub>
unsigned-suffix: one of
u U
long-suffix: one of
l L
long-long-suffix: one of
- ll LL</pre>
+ ll LL
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
An integer constant begins with a digit, but has no period or exponent part. It may have a
be represented.
<!--page 82 -->
<pre>
- Octal or Hexadecimal</pre>
+ Octal or Hexadecimal
+</pre>
Suffix Decimal Constant Constant
none int int
long long int long int
unsigned long int
long long int
- unsigned long long int</pre>
+ unsigned long long int
+</pre>
u or U unsigned int unsigned int
<pre>
unsigned long int unsigned long int
- unsigned long long int unsigned long long int</pre>
+ unsigned long long int unsigned long long int
+</pre>
l or L long int long int
<pre>
long long int unsigned long int
long long int
- unsigned long long int</pre>
+ unsigned long long int
+</pre>
Both u or U unsigned long int unsigned long int
and l or L unsigned long long int unsigned long long int
ll or LL long long int long long int
<pre>
- unsigned long long int</pre>
+ unsigned long long int
+</pre>
Both u or U unsigned long long int unsigned long long int
and ll or LL
its list and has no extended integer type, then the integer constant has no type.
<!--page 83 -->
-<a name="6.4.4.2" href="#6.4.4.2"><h5>6.4.4.2 Floating constants</h5></a>
+<h5><a name="6.4.4.2" href="#6.4.4.2">6.4.4.2 Floating constants</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<!--page 84 -->
decimal-floating-constant
hexadecimal-floating-constant
decimal-floating-constant:
- fractional-constant exponent-partopt floating-suffixopt
- digit-sequence exponent-part floating-suffixopt
+ fractional-constant exponent-part<sub>opt</sub> floating-suffix<sub>opt</sub>
+ digit-sequence exponent-part floating-suffix<sub>opt</sub>
hexadecimal-floating-constant:
hexadecimal-prefix hexadecimal-fractional-constant
- binary-exponent-part floating-suffixopt
+ binary-exponent-part floating-suffix<sub>opt</sub>
hexadecimal-prefix hexadecimal-digit-sequence
- binary-exponent-part floating-suffixopt
+ binary-exponent-part floating-suffix<sub>opt</sub>
fractional-constant:
- digit-sequenceopt . digit-sequence
+ digit-sequence<sub>opt</sub> . digit-sequence
digit-sequence .
exponent-part:
- e signopt digit-sequence
- E signopt digit-sequence
+ e sign<sub>opt</sub> digit-sequence
+ E sign<sub>opt</sub> digit-sequence
sign: one of
+ -
digit-sequence:
digit
digit-sequence digit
hexadecimal-fractional-constant:
- hexadecimal-digit-sequenceopt .
+ hexadecimal-digit-sequence<sub>opt</sub> .
hexadecimal-digit-sequence
hexadecimal-digit-sequence .
binary-exponent-part:
- p signopt digit-sequence
- P signopt digit-sequence
+ p sign<sub>opt</sub> digit-sequence
+ P sign<sub>opt</sub> digit-sequence
hexadecimal-digit-sequence:
hexadecimal-digit
hexadecimal-digit-sequence hexadecimal-digit
floating-suffix: one of
- f l F L</pre>
+ f l F L
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A floating constant has a significand part that may be followed by an exponent part and a
conversion of a floating constant shall not raise an exceptional condition or a floating-
point exception at execution time. All floating constants of the same source form<sup><a href="#note75"><b>75)</b></a></sup> shall
convert to the same internal format with the same value.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 6 -->
The implementation should produce a diagnostic message if a hexadecimal constant
cannot be represented exactly in its evaluation format; the implementation should then
floating constants (see <a href="#7.22.1.3">7.22.1.3</a>).
</small>
-<a name="6.4.4.3" href="#6.4.4.3"><h5>6.4.4.3 Enumeration constants</h5></a>
+<h5><a name="6.4.4.3" href="#6.4.4.3">6.4.4.3 Enumeration constants</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
enumeration-constant:
- identifier</pre>
+ identifier
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
An identifier declared as an enumeration constant has type int.
<p><b> Forward references</b>: enumeration specifiers (<a href="#6.7.2.2">6.7.2.2</a>).
-<a name="6.4.4.4" href="#6.4.4.4"><h5>6.4.4.4 Character constants</h5></a>
+<h5><a name="6.4.4.4" href="#6.4.4.4">6.4.4.4 Character constants</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<!--page 86 -->
\ octal-digit octal-digit octal-digit
hexadecimal-escape-sequence:
\x hexadecimal-digit
- hexadecimal-escape-sequence hexadecimal-digit</pre>
+ hexadecimal-escape-sequence hexadecimal-digit
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
An integer character constant is a sequence of one or more multibyte characters enclosed
The single-quote ', the double-quote ", the question-mark ?, the backslash \, and
arbitrary integer values are representable according to the following table of escape
sequences:
-<p><!--para 4 -->
<pre>
single quote ' \'
double quote " \"
question mark ? \?
backslash \ \\
octal character \octal digits
- hexadecimal character \x hexadecimal digits</pre>
+ hexadecimal character \x hexadecimal digits
+</pre>
+<p><!--para 4 -->
The double-quote " and question-mark ? are representable either by themselves or by the
escape sequences \" and \?, respectively, but the single-quote ' and the backslash \
shall be represented, respectively, by the escape sequences \' and \\.
none unsigned char
L the unsigned type corresponding to wchar_t
u char16_t
- U char32_t</pre>
+ U char32_t
+</pre>
<h6>Semantics</h6>
<p><!--para 10 -->
An integer character constant has type int. The value of an integer character constant
the result is not a token and a diagnostic is required. See ''future language directions'' (<a href="#6.11.4">6.11.4</a>).
</small>
-<a name="6.4.5" href="#6.4.5"><h4>6.4.5 String literals</h4></a>
+<h4><a name="6.4.5" href="#6.4.5">6.4.5 String literals</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
string-literal:
- encoding-prefixopt " s-char-sequenceopt "
+ encoding-prefix<sub>opt</sub> " s-char-sequence<sub>opt</sub> "
encoding-prefix:
u8
u
s-char:
any member of the source character set except
the double-quote ", backslash \, or new-line character
- escape-sequence</pre>
+ escape-sequence
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
A sequence of adjacent string literal tokens shall not include both a wide string literal and
<p><!--para 8 -->
EXAMPLE 1 This pair of adjacent character string literals
<pre>
- "\x12" "3"</pre>
+ "\x12" "3"
+</pre>
produces a single character string literal containing the two characters whose values are '\x12' and '3',
because escape sequences are converted into single members of the execution character set just prior to
adjacent string literal concatenation.
"a" "b" L"c"
"a" L"b" "c"
L"a" "b" L"c"
- L"a" L"b" L"c"</pre>
+ L"a" L"b" L"c"
+</pre>
is equivalent to the string literal
<pre>
- L"abc"</pre>
+ L"abc"
+</pre>
Likewise, each of the sequences
<pre>
"a" "b" u"c"
"a" u"b" "c"
u"a" "b" u"c"
- u"a" u"b" u"c"</pre>
+ u"a" u"b" u"c"
+</pre>
is equivalent to
<pre>
- u"abc"</pre>
+ u"abc"
+</pre>
<p><b> Forward references</b>: common definitions <a href="#7.19"><stddef.h></a> (<a href="#7.19">7.19</a>), the mbstowcs
function (<a href="#7.22.8.1">7.22.8.1</a>), Unicode utilities <a href="#7.27"><uchar.h></a> (<a href="#7.27">7.27</a>).
\0 escape sequence.
</small>
-<a name="6.4.6" href="#6.4.6"><h4>6.4.6 Punctuators</h4></a>
+<h4><a name="6.4.6" href="#6.4.6">6.4.6 Punctuators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
? : ; ...
= *= /= %= += -= <<= >>= &= ^= |=
, # ##
- <: :> <% %> %: %:%:</pre>
+ <: :> <% %> %: %:%:
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
A punctuator is a symbol that has independent syntactic and semantic significance.
<p><!--para 3 -->
In all aspects of the language, the six tokens<sup><a href="#note79"><b>79)</b></a></sup>
<pre>
- <: :> <% %> %: %:%:</pre>
+ <: :> <% %> %: %:%:
+</pre>
behave, respectively, the same as the six tokens
<pre>
- [ ] { } # ##</pre>
+ [ ] { } # ##
+</pre>
except for their spelling.<sup><a href="#note80"><b>80)</b></a></sup>
<p><b> Forward references</b>: expressions (<a href="#6.5">6.5</a>), declarations (<a href="#6.7">6.7</a>), preprocessing directives
(<a href="#6.10">6.10</a>), statements (<a href="#6.8">6.8</a>).
interchanged.
</small>
-<a name="6.4.7" href="#6.4.7"><h4>6.4.7 Header names</h4></a>
+<h4><a name="6.4.7" href="#6.4.7">6.4.7 Header names</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
q-char-sequence q-char
q-char:
any member of the source character set except
- the new-line character and "</pre>
+ the new-line character and "
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
The sequences in both forms of header names are mapped in an implementation-defined
<pre>
0x3<1/a.h>1e2
#include <1/a.h>
- #define const.member@$</pre>
+ #define const.member@$
+</pre>
forms the following sequence of preprocessing tokens (with each individual preprocessing token delimited
by a { on the left and a } on the right).
<pre>
{0x3}{<}{1}{/}{a}{.}{h}{>}{1e2}
{#}{include} {<1/a.h>}
- {#}{define} {const}{.}{member}{@}{$}</pre>
+ {#}{define} {const}{.}{member}{@}{$}
+</pre>
<p><b> Forward references</b>: source file inclusion (<a href="#6.10.2">6.10.2</a>).
<p><small><a name="note82" href="#note82">82)</a> For an example of a header name preprocessing token used in a #pragma directive, see <a href="#6.10.9">6.10.9</a>.
</small>
-<a name="6.4.8" href="#6.4.8"><h4>6.4.8 Preprocessing numbers</h4></a>
+<h4><a name="6.4.8" href="#6.4.8">6.4.8 Preprocessing numbers</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
pp-number E sign
pp-number p sign
pp-number P sign
- pp-number .</pre>
+ pp-number .
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A preprocessing number begins with a digit optionally preceded by a period (.) and may
<!--page 93 -->
-<a name="6.4.9" href="#6.4.9"><h4>6.4.9 Comments</h4></a>
+<h4><a name="6.4.9" href="#6.4.9">6.4.9 Comments</a></h4>
<p><!--para 1 -->
Except within a character constant, a string literal, or a comment, the characters /*
introduce a comment. The contents of such a comment are examined only to identify
glue(/,/) k(); // syntax error, not comment
/*//*/ l(); // equivalent to l();
m = n//**/o
- + p; // equivalent to m = n + p;</pre>
+ + p; // equivalent to m = n + p;
+</pre>
<p><small><a name="note83" href="#note83">83)</a> Thus, /* ... */ comments do not nest.
</small>
-<a name="6.5" href="#6.5"><h3>6.5 Expressions</h3></a>
+<h3><a name="6.5" href="#6.5">6.5 Expressions</a></h3>
<p><!--para 1 -->
An expression is a sequence of operators and operands that specifies computation of a
value, or that designates an object or a function, or that generates side effects, or that
<pre>
i = ++i + 1;
- a[i++] = i;</pre>
+ a[i++] = i;
+</pre>
while allowing
<pre>
i = i + 1;
- a[i] = i;</pre>
+ a[i] = i;
+</pre>
</small>
<p><small><a name="note85" href="#note85">85)</a> The syntax specifies the precedence of operators in the evaluation of an expression, which is the same
documented.
</small>
-<a name="6.5.1" href="#6.5.1"><h4>6.5.1 Primary expressions</h4></a>
+<h4><a name="6.5.1" href="#6.5.1">6.5.1 Primary expressions</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
constant
string-literal
( expression )
- generic-selection</pre>
+ generic-selection
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
An identifier is a primary expression, provided it has been declared as designating an
<p><small><a name="note91" href="#note91">91)</a> Thus, an undeclared identifier is a violation of the syntax.
</small>
-<a name="6.5.1.1" href="#6.5.1.1"><h5>6.5.1.1 Generic selection</h5></a>
+<h5><a name="6.5.1.1" href="#6.5.1.1">6.5.1.1 Generic selection</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
generic-assoc-list , generic-association
generic-association:
type-name : assignment-expression
- default : assignment-expression</pre>
+ default : assignment-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
A generic selection shall have no more than one default generic association. The type
long double: cbrtl, \
default: cbrt, \
float: cbrtf \
- )(X)</pre>
+ )(X)
+</pre>
-<a name="6.5.2" href="#6.5.2"><h4>6.5.2 Postfix operators</h4></a>
+<h4><a name="6.5.2" href="#6.5.2">6.5.2 Postfix operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<!--page 98 -->
postfix-expression:
primary-expression
postfix-expression [ expression ]
- postfix-expression ( argument-expression-listopt )
+ postfix-expression ( argument-expression-list<sub>opt</sub> )
postfix-expression . identifier
postfix-expression -> identifier
postfix-expression ++
( type-name ) { initializer-list , }
argument-expression-list:
assignment-expression
- argument-expression-list , assignment-expression</pre>
+ argument-expression-list , assignment-expression
+</pre>
-<a name="6.5.2.1" href="#6.5.2.1"><h5>6.5.2.1 Array subscripting</h5></a>
+<h5><a name="6.5.2.1" href="#6.5.2.1">6.5.2.1 Array subscripting</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
One of the expressions shall have type ''pointer to complete object type'', the other
<p><!--para 4 -->
EXAMPLE Consider the array object defined by the declaration
<pre>
- int x[3][5];</pre>
+ int x[3][5];
+</pre>
Here x is a 3 x 5 array of ints; more precisely, x is an array of three element objects, each of which is an
array of five ints. In the expression x[i], which is equivalent to (*((x)+(i))), x is first converted to
a pointer to the initial array of five ints. Then i is adjusted according to the type of x, which conceptually
<p><b> Forward references</b>: additive operators (<a href="#6.5.6">6.5.6</a>), address and indirection operators
(<a href="#6.5.3.2">6.5.3.2</a>), array declarators (<a href="#6.7.6.2">6.7.6.2</a>).
-<a name="6.5.2.2" href="#6.5.2.2"><h5>6.5.2.2 Function calls</h5></a>
+<h5><a name="6.5.2.2" href="#6.5.2.2">6.5.2.2 Function calls</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The expression that denotes the called function<sup><a href="#note92"><b>92)</b></a></sup> shall have type pointer to function
<p><!--para 12 -->
EXAMPLE In the function call
<pre>
- (*pf[f1()]) (f2(), f3() + f4())</pre>
+ (*pf[f1()]) (f2(), f3() + f4())
+</pre>
the functions f1, f2, f3, and f4 may be called in any order. All side effects have to be completed before
the function pointed to by pf[f1()] is called.
<p><small><a name="note94" href="#note94">94)</a> In other words, function executions do not ''interleave'' with each other.
</small>
-<a name="6.5.2.3" href="#6.5.2.3"><h5>6.5.2.3 Structure and union members</h5></a>
+<h5><a name="6.5.2.3" href="#6.5.2.3">6.5.2.3 Structure and union members</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The first operand of the . operator shall have an atomic, qualified, or unqualified
struct s { int i; const int ci; };
struct s s;
const struct s cs;
- volatile struct s vs;</pre>
+ volatile struct s vs;
+</pre>
the various members have the types:
<pre>
s.i int
cs.i const int
cs.ci const int
vs.i volatile int
- vs.ci volatile const int</pre>
+ vs.ci volatile const int
+</pre>
/* ... */
if (u.n.alltypes == 1)
if (sin(u.nf.doublenode) == 0.0)
- /* ... */</pre>
+ /* ... */
+</pre>
The following is not a valid fragment (because the union type is not visible within function f):
<pre>
struct t1 { int m; };
} u;
/* ... */
return f(&u.s1, &u.s2);
- }</pre>
+ }
+</pre>
<p><b> Forward references</b>: address and indirection operators (<a href="#6.5.3.2">6.5.3.2</a>), structure and union
specifiers (<a href="#6.7.2.1">6.7.2.1</a>).
can be safely accessed using a non-atomic object which is assigned to or from the atomic object.
</small>
-<a name="6.5.2.4" href="#6.5.2.4"><h5>6.5.2.4 Postfix increment and decrement operators</h5></a>
+<h5><a name="6.5.2.4" href="#6.5.2.4">6.5.2.4 Postfix increment and decrement operators</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The operand of the postfix increment or decrement operator shall have atomic, qualified,
T result = E;
do {
tmp = result + 1;
- } while (!atomic_compare_exchange_strong(&E, &result, tmp));</pre>
+ } while (!atomic_compare_exchange_strong(&E, &result, tmp));
+</pre>
with result being the result of the operation.
</small>
-<a name="6.5.2.5" href="#6.5.2.5"><h5>6.5.2.5 Compound literals</h5></a>
+<h5><a name="6.5.2.5" href="#6.5.2.5">6.5.2.5 Compound literals</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The type name shall specify a complete object type or an array of unknown size, but not a
<p><!--para 8 -->
EXAMPLE 1 The file scope definition
<pre>
- int *p = (int []){2, 4};</pre>
+ int *p = (int []){2, 4};
+</pre>
initializes p to point to the first element of an array of two ints, the first having the value two and the
second, four. The expressions in this compound literal are required to be constant. The unnamed object
has static storage duration.
/*...*/
p = (int [2]){*p};
/*...*/
- }</pre>
+ }
+</pre>
p is assigned the address of the first element of an array of two ints, the first having the value previously
pointed to by p and the second, zero. The expressions in this compound literal need not be constant. The
unnamed object has automatic storage duration.
created using compound literals can be passed to functions without depending on member order:
<pre>
drawline((struct point){.x=1, .y=1},
- (struct point){.x=3, .y=4});</pre>
+ (struct point){.x=3, .y=4});
+</pre>
Or, if drawline instead expected pointers to struct point:
<!--page 105 -->
<pre>
drawline(&(struct point){.x=1, .y=1},
- &(struct point){.x=3, .y=4});</pre>
+ &(struct point){.x=3, .y=4});
+</pre>
<p><!--para 11 -->
EXAMPLE 4 A read-only compound literal can be specified through constructions like:
<pre>
- (const float []){1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6}</pre>
+ (const float []){1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6}
+</pre>
<p><!--para 12 -->
EXAMPLE 5 The following three expressions have different meanings:
<pre>
"/tmp/fileXXXXXX"
(char []){"/tmp/fileXXXXXX"}
- (const char []){"/tmp/fileXXXXXX"}</pre>
+ (const char []){"/tmp/fileXXXXXX"}
+</pre>
The first always has static storage duration and has type array of char, but need not be modifiable; the last
two have automatic storage duration when they occur within the body of a function, and the first of these
two is modifiable.
EXAMPLE 6 Like string literals, const-qualified compound literals can be placed into read-only memory
and can even be shared. For example,
<pre>
- (const char []){"abc"} == "abc"</pre>
+ (const char []){"abc"} == "abc"
+</pre>
might yield 1 if the literals' storage is shared.
<p><!--para 14 -->
<pre>
struct int_list { int car; struct int_list *cdr; };
struct int_list endless_zeros = {0, &endless_zeros};
- eval(endless_zeros);</pre>
+ eval(endless_zeros);
+</pre>
<p><!--para 15 -->
EXAMPLE 8 Each compound literal creates only a single object in a given scope:
q = p, p = &((struct s){ j++ });
if (j < 2) goto again;
return p == q && q->i == 1;
- }</pre>
+ }
+</pre>
The function f() always returns the value 1.
<p><!--para 16 -->
Note that if an iteration statement were used instead of an explicit goto and a labeled statement, the
the same or overlapping representations.
</small>
-<a name="6.5.3" href="#6.5.3"><h4>6.5.3 Unary operators</h4></a>
+<h4><a name="6.5.3" href="#6.5.3">6.5.3 Unary operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
sizeof ( type-name )
alignof ( type-name )
unary-operator: one of
- & * + - ~ !</pre>
+ & * + - ~ !
+</pre>
-<a name="6.5.3.1" href="#6.5.3.1"><h5>6.5.3.1 Prefix increment and decrement operators</h5></a>
+<h5><a name="6.5.3.1" href="#6.5.3.1">6.5.3.1 Prefix increment and decrement operators</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The operand of the prefix increment or decrement operator shall have atomic, qualified,
operand is decremented.
<p><b> Forward references</b>: additive operators (<a href="#6.5.6">6.5.6</a>), compound assignment (<a href="#6.5.16.2">6.5.16.2</a>).
-<a name="6.5.3.2" href="#6.5.3.2"><h5>6.5.3.2 Address and indirection operators</h5></a>
+<h5><a name="6.5.3.2" href="#6.5.3.2">6.5.3.2 Address and indirection operators</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The operand of the unary & operator shall be either a function designator, the result of a
end of its lifetime.
</small>
-<a name="6.5.3.3" href="#6.5.3.3"><h5>6.5.3.3 Unary arithmetic operators</h5></a>
+<h5><a name="6.5.3.3" href="#6.5.3.3">6.5.3.3 Unary arithmetic operators</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The operand of the unary + or - operator shall have arithmetic type; of the ~ operator,
<!--page 108 -->
-<a name="6.5.3.4" href="#6.5.3.4"><h5>6.5.3.4 The sizeof and alignof operators</h5></a>
+<h5><a name="6.5.3.4" href="#6.5.3.4">6.5.3.4 The sizeof and alignof operators</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The sizeof operator shall not be applied to an expression that has function type or an
allocate and return a pointer to void. For example:
<pre>
extern void *alloc(size_t);
- double *dp = alloc(sizeof *dp);</pre>
+ double *dp = alloc(sizeof *dp);
+</pre>
The implementation of the alloc function should ensure that its return value is aligned suitably for
conversion to a pointer to double.
<p><!--para 7 -->
EXAMPLE 2 Another use of the sizeof operator is to compute the number of elements in an array:
<pre>
- sizeof array / sizeof array[0]</pre>
+ sizeof array / sizeof array[0]
+</pre>
<p><!--para 8 -->
EXAMPLE 3 In this example, the size of a variable length array is computed and returned from a
function:
<pre>
- #include <a href="#7.19"><stddef.h></a></pre>
+ #include <a href="#7.19"><stddef.h></a>
+</pre>
size_t size;
size = fsize3(10); // fsize3 returns 13
return 0;
- }</pre>
+ }
+</pre>
<p><b> Forward references</b>: common definitions <a href="#7.19"><stddef.h></a> (<a href="#7.19">7.19</a>), declarations (<a href="#6.7">6.7</a>),
structure and union specifiers (<a href="#6.7.2.1">6.7.2.1</a>), type names (<a href="#6.7.7">6.7.7</a>), array declarators (<a href="#6.7.6.2">6.7.6.2</a>).
size of the adjusted (pointer) type (see <a href="#6.9.1">6.9.1</a>).
</small>
-<a name="6.5.4" href="#6.5.4"><h4>6.5.4 Cast operators</h4></a>
+<h4><a name="6.5.4" href="#6.5.4">6.5.4 Cast operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
cast-expression:
unary-expression
- ( type-name ) cast-expression</pre>
+ ( type-name ) cast-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Unless the type name specifies a void type, the type name shall specify atomic, qualified,
unqualified version of the type.
</small>
-<a name="6.5.5" href="#6.5.5"><h4>6.5.5 Multiplicative operators</h4></a>
+<h4><a name="6.5.5" href="#6.5.5">6.5.5 Multiplicative operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
cast-expression
multiplicative-expression * cast-expression
multiplicative-expression / cast-expression
- multiplicative-expression % cast-expression</pre>
+ multiplicative-expression % cast-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each of the operands shall have arithmetic type. The operands of the % operator shall
<p><small><a name="note105" href="#note105">105)</a> This is often called ''truncation toward zero''.
</small>
-<a name="6.5.6" href="#6.5.6"><h4>6.5.6 Additive operators</h4></a>
+<h4><a name="6.5.6" href="#6.5.6">6.5.6 Additive operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
additive-expression:
multiplicative-expression
additive-expression + multiplicative-expression
- additive-expression - multiplicative-expression</pre>
+ additive-expression - multiplicative-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
For addition, either both operands shall have arithmetic type, or one operand shall be a
expression (Q)+1 does not point to an element of the array object.<sup><a href="#note106"><b>106)</b></a></sup>
<p><!--para 10 -->
EXAMPLE Pointer arithmetic is well defined with pointers to variable length array types.
-<p><!--para 11 -->
<pre>
{
int n = 4, m = 3;
p += 1; // p == &a[1]
(*p)[2] = 99; // a[1][2] == 99
n = p - a; // n == 1
- }</pre>
+ }
+</pre>
+<p><!--para 11 -->
If array a in the above example were declared to be an array of known constant size, and pointer p were
declared to be a pointer to an array of the same known constant size (pointing to a), the results would be
the same.
element'' requirements.
</small>
-<a name="6.5.7" href="#6.5.7"><h4>6.5.7 Bitwise shift operators</h4></a>
+<h4><a name="6.5.7" href="#6.5.7">6.5.7 Bitwise shift operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
shift-expression:
additive-expression
shift-expression << additive-expression
- shift-expression >> additive-expression</pre>
+ shift-expression >> additive-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each of the operands shall have integer type.
part of the quotient of E1 / 2E2 . If E1 has a signed type and a negative value, the
resulting value is implementation-defined.
-<a name="6.5.8" href="#6.5.8"><h4>6.5.8 Relational operators</h4></a>
+<h4><a name="6.5.8" href="#6.5.8">6.5.8 Relational operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
relational-expression < shift-expression
relational-expression > shift-expression
relational-expression <= shift-expression
- relational-expression >= shift-expression</pre>
+ relational-expression >= shift-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
One of the following shall hold:
means (a<b)<c; in other words, ''if a is less than b, compare 1 to c; otherwise, compare 0 to c''.
</small>
-<a name="6.5.9" href="#6.5.9"><h4>6.5.9 Equality operators</h4></a>
+<h4><a name="6.5.9" href="#6.5.9">6.5.9 Equality operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
equality-expression:
relational-expression
equality-expression == relational-expression
- equality-expression != relational-expression</pre>
+ equality-expression != relational-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
One of the following shall hold:
behavior.
</small>
-<a name="6.5.10" href="#6.5.10"><h4>6.5.10 Bitwise AND operator</h4></a>
+<h4><a name="6.5.10" href="#6.5.10">6.5.10 Bitwise AND operator</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
AND-expression:
equality-expression
- AND-expression & equality-expression</pre>
+ AND-expression & equality-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each of the operands shall have integer type.
<!--page 116 -->
-<a name="6.5.11" href="#6.5.11"><h4>6.5.11 Bitwise exclusive OR operator</h4></a>
+<h4><a name="6.5.11" href="#6.5.11">6.5.11 Bitwise exclusive OR operator</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
exclusive-OR-expression:
AND-expression
- exclusive-OR-expression ^ AND-expression</pre>
+ exclusive-OR-expression ^ AND-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each of the operands shall have integer type.
in the result is set if and only if exactly one of the corresponding bits in the converted
operands is set).
-<a name="6.5.12" href="#6.5.12"><h4>6.5.12 Bitwise inclusive OR operator</h4></a>
+<h4><a name="6.5.12" href="#6.5.12">6.5.12 Bitwise inclusive OR operator</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
inclusive-OR-expression:
exclusive-OR-expression
- inclusive-OR-expression | exclusive-OR-expression</pre>
+ inclusive-OR-expression | exclusive-OR-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each of the operands shall have integer type.
operands is set).
<!--page 117 -->
-<a name="6.5.13" href="#6.5.13"><h4>6.5.13 Logical AND operator</h4></a>
+<h4><a name="6.5.13" href="#6.5.13">6.5.13 Logical AND operator</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
logical-AND-expression:
inclusive-OR-expression
- logical-AND-expression && inclusive-OR-expression</pre>
+ logical-AND-expression && inclusive-OR-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each of the operands shall have scalar type.
the first and second operands. If the first operand compares equal to 0, the second
operand is not evaluated.
-<a name="6.5.14" href="#6.5.14"><h4>6.5.14 Logical OR operator</h4></a>
+<h4><a name="6.5.14" href="#6.5.14">6.5.14 Logical OR operator</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
logical-OR-expression:
logical-AND-expression
- logical-OR-expression || logical-AND-expression</pre>
+ logical-OR-expression || logical-AND-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Each of the operands shall have scalar type.
not evaluated.
<!--page 118 -->
-<a name="6.5.15" href="#6.5.15"><h4>6.5.15 Conditional operator</h4></a>
+<h4><a name="6.5.15" href="#6.5.15">6.5.15 Conditional operator</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
conditional-expression:
logical-OR-expression
- logical-OR-expression ? expression : conditional-expression</pre>
+ logical-OR-expression ? expression : conditional-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
The first operand shall have scalar type.
const int *c_ip;
volatile int *v_ip;
int *ip;
- const char *c_cp;</pre>
+ const char *c_cp;
+</pre>
the third column in the following table is the common type that is the result of a conditional expression in
which the first two columns are the second and third operands (in either order):
<pre>
c_ip v_ip const volatile int *
vp c_cp const void *
ip c_ip const int *
- vp ip void *</pre>
+ vp ip void *
+</pre>
<h6>footnotes</h6>
<p><small><a name="note110" href="#note110">110)</a> A conditional expression does not yield an lvalue.
</small>
-<a name="6.5.16" href="#6.5.16"><h4>6.5.16 Assignment operators</h4></a>
+<h4><a name="6.5.16" href="#6.5.16">6.5.16 Assignment operators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
conditional-expression
unary-expression assignment-operator assignment-expression
assignment-operator: one of
- = *= /= %= += -= <<= >>= &= ^= |=</pre>
+ = *= /= %= += -= <<= >>= &= ^= |=
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
An assignment operator shall have a modifiable lvalue as its left operand.
when the object has volatile-qualified type.
</small>
-<a name="6.5.16.1" href="#6.5.16.1"><h5>6.5.16.1 Simple assignment</h5></a>
+<h5><a name="6.5.16.1" href="#6.5.16.1">6.5.16.1 Simple assignment</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
One of the following shall hold:<sup><a href="#note112"><b>112)</b></a></sup>
char c;
/* ... */
if ((c = f()) == -1)
- /* ... */</pre>
+ /* ... */
+</pre>
the int value returned by the function may be truncated when stored in the char, and then converted back
to int width prior to the comparison. In an implementation in which ''plain'' char has the same range of
values as unsigned char (and char is narrower than int), the result of the conversion cannot be
char c;
int i;
long l;
- l = (c = i);</pre>
+ l = (c = i);
+</pre>
the value of i is converted to the type of the assignment expression c = i, that is, char type. The value
of the expression enclosed in parentheses is then converted to the type of the outer assignment expression,
that is, long int type.
const char c = 'A';
cpp = &p; // constraint violation
*cpp = &c; // valid
- *p = 0; // valid</pre>
+ *p = 0; // valid
+</pre>
The first assignment is unsafe because it would allow the following valid code to attempt to change the
value of the const object c.
not volatile from the type int volatile * const).
</small>
-<a name="6.5.16.2" href="#6.5.16.2"><h5>6.5.16.2 Compound assignment</h5></a>
+<h5><a name="6.5.16.2" href="#6.5.16.2">6.5.16.2 Compound assignment</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
For the operators += and -= only, either the left operand shall be an atomic, qualified, or
T result;
do {
result = tmp op (E2);
- } while (!atomic_compare_exchange_strong(&E1, &tmp, result));</pre>
+ } while (!atomic_compare_exchange_strong(&E1, &tmp, result));
+</pre>
with result being the result of the operation.
</small>
-<a name="6.5.17" href="#6.5.17"><h4>6.5.17 Comma operator</h4></a>
+<h4><a name="6.5.17" href="#6.5.17">6.5.17 Comma operator</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
expression:
assignment-expression
- expression , assignment-expression</pre>
+ expression , assignment-expression
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
The left operand of a comma operator is evaluated as a void expression; there is a
of initializers). On the other hand, it can be used within a parenthesized expression or within the second
expression of a conditional operator in such contexts. In the function call
<pre>
- f(a, (t=3, t+2), c)</pre>
+ f(a, (t=3, t+2), c)
+</pre>
the function has three arguments, the second of which has the value 5.
<p><b> Forward references</b>: initialization (<a href="#6.7.9">6.7.9</a>).
<p><small><a name="note114" href="#note114">114)</a> A comma operator does not yield an lvalue.
</small>
-<a name="6.6" href="#6.6"><h3>6.6 Constant expressions</h3></a>
+<h3><a name="6.6" href="#6.6">6.6 Constant expressions</a></h3>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
constant-expression:
- conditional-expression</pre>
+ conditional-expression
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A constant expression can be evaluated during translation rather than runtime, and
<p><small><a name="note118" href="#note118">118)</a> Thus, in the following initialization,
<pre>
- static int i = 2 || 1 / 0;</pre>
+ static int i = 2 || 1 / 0;
+</pre>
the expression is a valid integer constant expression with value one.
</small>
-<a name="6.7" href="#6.7"><h3>6.7 Declarations</h3></a>
+<h3><a name="6.7" href="#6.7">6.7 Declarations</a></h3>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
declaration:
- declaration-specifiers init-declarator-listopt ;
+ declaration-specifiers init-declarator-list<sub>opt</sub> ;
static_assert-declaration
declaration-specifiers:
- storage-class-specifier declaration-specifiersopt
- type-specifier declaration-specifiersopt
- type-qualifier declaration-specifiersopt
- function-specifier declaration-specifiersopt
- alignment-specifier declaration-specifiersopt
+ storage-class-specifier declaration-specifiers<sub>opt</sub>
+ type-specifier declaration-specifiers<sub>opt</sub>
+ type-qualifier declaration-specifiers<sub>opt</sub>
+ function-specifier declaration-specifiers<sub>opt</sub>
+ alignment-specifier declaration-specifiers<sub>opt</sub>
init-declarator-list:
init-declarator
init-declarator-list , init-declarator
init-declarator:
declarator
- declarator = initializer</pre>
+ declarator = initializer
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
A declaration other than a static_assert declaration shall declare at least a declarator
<p><small><a name="note119" href="#note119">119)</a> Function definitions have a different syntax, described in <a href="#6.9.1">6.9.1</a>.
</small>
-<a name="6.7.1" href="#6.7.1"><h4>6.7.1 Storage-class specifiers</h4></a>
+<h4><a name="6.7.1" href="#6.7.1">6.7.1 Storage-class specifiers</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
static
_Thread_local
auto
- register</pre>
+ register
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
At most, one storage-class specifier may be given in the declaration specifiers in a
register is sizeof.
</small>
-<a name="6.7.2" href="#6.7.2"><h4>6.7.2 Type specifiers</h4></a>
+<h4><a name="6.7.2" href="#6.7.2">6.7.2 Type specifiers</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
atomic-type-specifier
struct-or-union-specifier
enum-specifier
- typedef-name</pre>
+ typedef-name
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
At least one type specifier shall be given in the declaration specifiers in each declaration,
<p><b> Forward references</b>: atomic type specifiers (<a href="#6.7.2.4">6.7.2.4</a>), enumeration specifiers (<a href="#6.7.2.2">6.7.2.2</a>),
structure and union specifiers (<a href="#6.7.2.1">6.7.2.1</a>), tags (<a href="#6.7.2.3">6.7.2.3</a>), type definitions (<a href="#6.7.8">6.7.8</a>).
-<a name="6.7.2.1" href="#6.7.2.1"><h5>6.7.2.1 Structure and union specifiers</h5></a>
+<h5><a name="6.7.2.1" href="#6.7.2.1">6.7.2.1 Structure and union specifiers</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
struct-or-union-specifier:
- struct-or-union identifieropt { struct-declaration-list }
+ struct-or-union identifier<sub>opt</sub> { struct-declaration-list }
struct-or-union identifier
struct-or-union:
struct
struct-declaration
struct-declaration-list struct-declaration
struct-declaration:
- specifier-qualifier-list struct-declarator-listopt ;
+ specifier-qualifier-list struct-declarator-list<sub>opt</sub> ;
static_assert-declaration
specifier-qualifier-list:
- type-specifier specifier-qualifier-listopt
- type-qualifier specifier-qualifier-listopt
+ type-specifier specifier-qualifier-list<sub>opt</sub>
+ type-qualifier specifier-qualifier-list<sub>opt</sub>
struct-declarator-list:
struct-declarator
struct-declarator-list , struct-declarator
struct-declarator:
declarator
- declaratoropt : constant-expression</pre>
+ declarator<sub>opt</sub> : constant-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
A struct-declaration that does not declare an anonymous structure or anonymous union
} v1;
v1.i = 2; // valid
v1.k = 3; // invalid: inner structure is not anonymous
- v1.w.k = 5; // valid</pre>
+ v1.w.k = 5; // valid
+</pre>
<p><!--para 20 -->
EXAMPLE 2 After the declaration:
<pre>
- struct s { int n; double d[]; };</pre>
+ struct s { int n; double d[]; };
+</pre>
the structure struct s has a flexible array member d. A typical way to use this is:
<pre>
int m = /* some value */;
- struct s *p = malloc(sizeof (struct s) + sizeof (double [m]));</pre>
+ struct s *p = malloc(sizeof (struct s) + sizeof (double [m]));
+</pre>
and assuming that the call to malloc succeeds, the object pointed to by p behaves, for most purposes, as if
p had been declared as:
<pre>
- struct { int n; double d[m]; } *p;</pre>
+ struct { int n; double d[m]; } *p;
+</pre>
(there are circumstances in which this equivalence is broken; in particular, the offsets of member d might
not be the same).
<p><!--para 21 -->
struct s t1 = { 0 }; // valid
struct s t2 = { 1, { <a href="#4.2">4.2</a> }}; // invalid
t1.n = 4; // valid
- t1.d[0] = <a href="#4.2">4.2</a>; // might be undefined behavior</pre>
+ t1.d[0] = <a href="#4.2">4.2</a>; // might be undefined behavior
+</pre>
The initialization of t2 is invalid (and violates a constraint) because struct s is treated as if it did not
contain member d. The assignment to t1.d[0] is probably undefined behavior, but it is possible that
<pre>
- sizeof (struct s) >= offsetof(struct s, d) + sizeof (double)</pre>
+ sizeof (struct s) >= offsetof(struct s, d) + sizeof (double)
+</pre>
in which case the assignment would be legitimate. Nevertheless, it cannot appear in strictly conforming
code.
<!--page 133 -->
<p><!--para 22 -->
After the further declaration:
<pre>
- struct ss { int n; };</pre>
+ struct ss { int n; };
+</pre>
the expressions:
<pre>
sizeof (struct s) >= sizeof (struct ss)
- sizeof (struct s) >= offsetof(struct s, d)</pre>
+ sizeof (struct s) >= offsetof(struct s, d)
+</pre>
are always equal to 1.
<p><!--para 23 -->
If sizeof (double) is 8, then after the following code is executed:
struct s *s1;
struct s *s2;
s1 = malloc(sizeof (struct s) + 64);
- s2 = malloc(sizeof (struct s) + 46);</pre>
+ s2 = malloc(sizeof (struct s) + 46);
+</pre>
and assuming that the calls to malloc succeed, the objects pointed to by s1 and s2 behave, for most
purposes, as if the identifiers had been declared as:
-<p><!--para 24 -->
<pre>
struct { int n; double d[8]; } *s1;
- struct { int n; double d[5]; } *s2;</pre>
+ struct { int n; double d[5]; } *s2;
+</pre>
+<p><!--para 24 -->
Following the further successful assignments:
<pre>
s1 = malloc(sizeof (struct s) + 10);
- s2 = malloc(sizeof (struct s) + 6);</pre>
+ s2 = malloc(sizeof (struct s) + 6);
+</pre>
they then behave as if the declarations were:
<pre>
- struct { int n; double d[1]; } *s1, *s2;</pre>
+ struct { int n; double d[1]; } *s1, *s2;
+</pre>
and:
-<p><!--para 25 -->
<pre>
double *dp;
dp = &(s1->d[0]); // valid
*dp = 42; // valid
dp = &(s2->d[0]); // valid
- *dp = 42; // undefined behavior</pre>
+ *dp = 42; // undefined behavior
+</pre>
+<p><!--para 25 -->
The assignment:
<pre>
- *s1 = *s2;</pre>
+ *s1 = *s2;
+</pre>
only copies the member n; if any of the array elements are within the first sizeof (struct s) bytes
of the structure, they might be copied or simply overwritten with indeterminate values.
layouts.
</small>
-<a name="6.7.2.2" href="#6.7.2.2"><h5>6.7.2.2 Enumeration specifiers</h5></a>
+<h5><a name="6.7.2.2" href="#6.7.2.2">6.7.2.2 Enumeration specifiers</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
enum-specifier:
- enum identifieropt { enumerator-list }
- enum identifieropt { enumerator-list , }
+ enum identifier<sub>opt</sub> { enumerator-list }
+ enum identifier<sub>opt</sub> { enumerator-list , }
enum identifier
enumerator-list:
enumerator
enumerator-list , enumerator
enumerator:
enumeration-constant
- enumeration-constant = constant-expression</pre>
+ enumeration-constant = constant-expression
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
The expression that defines the value of an enumeration constant shall be an integer
col = claret;
cp = &col;
if (*cp != burgundy)
- /* ... */</pre>
+ /* ... */
+</pre>
makes hue the tag of an enumeration, and then declares col as an object that has that type and cp as a
pointer to an object that has that type. The enumerated values are in the set { 0, 1, 20, 21 }.
been seen.
</small>
-<a name="6.7.2.3" href="#6.7.2.3"><h5>6.7.2.3 Tags</h5></a>
+<h5><a name="6.7.2.3" href="#6.7.2.3">6.7.2.3 Tags</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
A specific type shall have its content defined at most once.
<p><!--para 3 -->
A type specifier of the form
<pre>
- enum identifier</pre>
+ enum identifier
+</pre>
without an enumerator list shall only appear after the type it specifies is complete.
<h6>Semantics</h6>
<p><!--para 4 -->
<!--page 136 -->
<pre>
- struct-or-union identifieropt { struct-declaration-list }</pre>
+ struct-or-union identifier<sub>opt</sub> { struct-declaration-list }
+</pre>
or
<pre>
- enum identifieropt { enumerator-list }</pre>
+ enum identifier<sub>opt</sub> { enumerator-list }
+</pre>
or
<pre>
- enum identifieropt { enumerator-list , }</pre>
+ enum identifier<sub>opt</sub> { enumerator-list , }
+</pre>
declares a structure, union, or enumerated type. The list defines the structure content,
union content, or enumeration content. If an identifier is provided,<sup><a href="#note130"><b>130)</b></a></sup> the type specifier
also declares the identifier to be the tag of that type.
<p><!--para 7 -->
A declaration of the form
<pre>
- struct-or-union identifier ;</pre>
+ struct-or-union identifier ;
+</pre>
specifies a structure or union type and declares the identifier as a tag of that type.<sup><a href="#note131"><b>131)</b></a></sup>
<p><!--para 8 -->
If a type specifier of the form
<pre>
- struct-or-union identifier</pre>
+ struct-or-union identifier
+</pre>
occurs other than as part of one of the above forms, and no other declaration of the
identifier as a tag is visible, then it declares an incomplete structure or union type, and
- declares the identifier as the tag of that type.131)
+ declares the identifier as the tag of that type.<sup><a href="#note131"><b>131)</b></a></sup>
<p><!--para 9 -->
If a type specifier of the form
<pre>
- struct-or-union identifier</pre>
+ struct-or-union identifier
+</pre>
or
<pre>
- enum identifier</pre>
+ enum identifier
+</pre>
occurs other than as part of one of the above forms, and a declaration of the identifier as a
tag is visible, then it specifies the same type as that other declaration, and does not
redeclare the tag.
struct tnode {
int count;
struct tnode *left, *right;
- };</pre>
+ };
+</pre>
specifies a structure that contains an integer and two pointers to objects of the same type. Once this
declaration has been given, the declaration
<!--page 137 -->
<pre>
- struct tnode s, *sp;</pre>
+ struct tnode s, *sp;
+</pre>
declares s to be an object of the given type and sp to be a pointer to an object of the given type. With
these declarations, the expression sp->left refers to the left struct tnode pointer of the object to
which sp points; the expression s.right->count designates the count member of the right struct
int count;
TNODE *left, *right;
};
- TNODE s, *sp;</pre>
+ TNODE s, *sp;
+</pre>
<p><!--para 12 -->
EXAMPLE 2 To illustrate the use of prior declaration of a tag to specify a pair of mutually referential
structures, the declarations
<pre>
struct s1 { struct s2 *s2p; /* ... */ }; // D1
- struct s2 { struct s1 *s1p; /* ... */ }; // D2</pre>
+ struct s2 { struct s1 *s1p; /* ... */ }; // D2
+</pre>
specify a pair of structures that contain pointers to each other. Note, however, that if s2 were already
declared as a tag in an enclosing scope, the declaration D1 would refer to it, not to the tag s2 declared in
D2. To eliminate this context sensitivity, the declaration
<pre>
- struct s2;</pre>
+ struct s2;
+</pre>
may be inserted ahead of D1. This declares a new tag s2 in the inner scope; the declaration D2 then
completes the specification of the new type.
<p><small><a name="note131" href="#note131">131)</a> A similar construction with enum does not exist.
</small>
-<a name="6.7.2.4" href="#6.7.2.4"><h5>6.7.2.4 Atomic type specifiers</h5></a>
+<h5><a name="6.7.2.4" href="#6.7.2.4">6.7.2.4 Atomic type specifiers</a></h5>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
atomic-type-specifier:
- _Atomic ( type-name )</pre>
+ _Atomic ( type-name )
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Atomic type specifiers shall not be used if the implementation does not support atomic
interpreted as a type specifier (with a type name), not as a type qualifier.
<!--page 138 -->
-<a name="6.7.3" href="#6.7.3"><h4>6.7.3 Type qualifiers</h4></a>
+<h4><a name="6.7.3" href="#6.7.3">6.7.3 Type qualifiers</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
const
restrict
volatile
- _Atomic</pre>
+ _Atomic
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Types other than pointer types whose referenced type is an object type shall not be
<p><!--para 11 -->
EXAMPLE 1 An object declared
<pre>
- extern const volatile int real_time_clock;</pre>
+ extern const volatile int real_time_clock;
+</pre>
may be modifiable by hardware, but cannot be assigned to, incremented, or decremented.
<p><!--para 12 -->
pi = &ncs.mem; // valid
pi = &cs.mem; // violates type constraints for =
pci = &cs.mem; // valid
- pi = a[0]; // invalid: a[0] has type ''const int *''</pre>
+ pi = a[0]; // invalid: a[0] has type ''const int *''
+</pre>
<p><!--para 13 -->
EXAMPLE 3 The declaration
<pre>
- _Atomic volatile int *p;</pre>
+ _Atomic volatile int *p;
+</pre>
specifies that p has the type ''pointer to volatile atomic int'', a pointer to a volatile-qualified atomic type.
<p><small><a name="note136" href="#note136">136)</a> Both of these can occur through the use of typedefs.
</small>
-<a name="6.7.3.1" href="#6.7.3.1"><h5>6.7.3.1 Formal definition of restrict</h5></a>
+<h5><a name="6.7.3.1" href="#6.7.3.1">6.7.3.1 Formal definition of restrict</a></h5>
<p><!--para 1 -->
Let D be a declaration of an ordinary identifier that provides a means of designating an
object P as a restrict-qualified pointer to type T.
<pre>
int * restrict a;
int * restrict b;
- extern int c[];</pre>
+ extern int c[];
+</pre>
assert that if an object is accessed using one of a, b, or c, and that object is modified anywhere in the
program, then it is never accessed using either of the other two.
{
while (n-- > 0)
*p++ = *q++;
- }</pre>
+ }
+</pre>
assert that, during each execution of the function, if an object is accessed through one of the pointer
parameters, then it is not also accessed through the other.
<p><!--para 9 -->
extern int d[100];
f(50, d + 50, d); // valid
f(50, d + 1, d); // undefined behavior
- }</pre>
+ }
+</pre>
<p><!--para 10 -->
EXAMPLE 3 The function parameter declarations
int i;
for (i = 0; i < n; i++)
p[i] = q[i] + r[i];
- }</pre>
+ }
+</pre>
illustrate how an unmodified object can be aliased through two restricted pointers. In particular, if a and b
are disjoint arrays, a call of the form h(100, a, b, b) has defined behavior, because array b is not
modified within function h.
function call and an equivalent nested block. With one exception, only ''outer-to-inner'' assignments
between restricted pointers declared in nested blocks have defined behavior.
<!--page 142 -->
-<p><!--para 12 -->
<pre>
{
int * restrict p1;
p1 = q2; // undefined behavior
p2 = q2; // undefined behavior
}
- }</pre>
+ }
+</pre>
+<p><!--para 12 -->
The one exception allows the value of a restricted pointer to be carried out of the block in which it (or, more
precisely, the ordinary identifier used to designate it) is declared when that block finishes execution. For
example, this permits new_vector to return a vector.
t.n = n;
t.v = malloc(n * sizeof (float));
return t;
- }</pre>
+ }
+</pre>
<h6>footnotes</h6>
expressions *p and p[1] are not.
</small>
-<a name="6.7.4" href="#6.7.4"><h4>6.7.4 Function specifiers</h4></a>
+<h4><a name="6.7.4" href="#6.7.4">6.7.4 Function specifiers</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
function-specifier:
inline
- _Noreturn</pre>
+ _Noreturn
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
Function specifiers shall be used only in the declaration of an identifier for a function.
function uses the inline definition or the external definition.<sup><a href="#note140"><b>140)</b></a></sup>
<p><!--para 8 -->
A function declared with a _Noreturn function specifier shall not return to its caller.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 9 -->
The implementation should produce a diagnostic message for a function declared with a
_Noreturn function specifier that appears to be capable of returning to its caller.
EXAMPLE 1 The declaration of an inline function with external linkage can result in either an external
definition, or a definition available for use only within the translation unit. A file scope declaration with
extern creates an external definition. The following example shows an entire translation unit.
-<p><!--para 11 -->
<pre>
inline double fahr(double t)
{
{
/* A translator may perform inline substitutions */
return is_fahr ? cels(temp) : fahr(temp);
- }</pre>
+ }
+</pre>
+<p><!--para 11 -->
Note that the definition of fahr is an external definition because fahr is also declared with extern, but
the definition of cels is an inline definition. Because cels has external linkage and is referenced, an
external definition has to appear in another translation unit (see <a href="#6.9">6.9</a>); the inline definition and the external
}
_Noreturn void g (int i) { // causes undefined behavior if i <= 0
if (i > 0) abort();
- }</pre>
+ }
+</pre>
<p><b> Forward references</b>: function definitions (<a href="#6.9.1">6.9.1</a>).
duration are also distinct in each of the definitions.
</small>
-<a name="6.7.5" href="#6.7.5"><h4>6.7.5 Alignment specifier</h4></a>
+<h4><a name="6.7.5" href="#6.7.5">6.7.5 Alignment specifier</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
alignment-specifier:
_Alignas ( type-name )
- _Alignas ( constant-expression )</pre>
+ _Alignas ( constant-expression )
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
An alignment attribute shall not be specified in a declaration of a typedef, or a bit-field, or
declaration.
</small>
-<a name="6.7.6" href="#6.7.6"><h4>6.7.6 Declarators</h4></a>
+<h4><a name="6.7.6" href="#6.7.6">6.7.6 Declarators</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
declarator:
- pointeropt direct-declarator
+ pointer<sub>opt</sub> direct-declarator
direct-declarator:
identifier
( declarator )
- direct-declarator [ type-qualifier-listopt assignment-expressionopt ]
- direct-declarator [ static type-qualifier-listopt assignment-expression ]
+ direct-declarator [ type-qualifier-list<sub>opt</sub> assignment-expression<sub>opt</sub> ]
+ direct-declarator [ static type-qualifier-list<sub>opt</sub> assignment-expression ]
direct-declarator [ type-qualifier-list static assignment-expression ]
- direct-declarator [ type-qualifier-listopt * ]
+ direct-declarator [ type-qualifier-list<sub>opt</sub> * ]
direct-declarator ( parameter-type-list )
- direct-declarator ( identifier-listopt )
+ direct-declarator ( identifier-list<sub>opt</sub> )
pointer:
- * type-qualifier-listopt
- * type-qualifier-listopt pointer
+ * type-qualifier-list<sub>opt</sub>
+ * type-qualifier-list<sub>opt</sub> pointer
type-qualifier-list:
type-qualifier
type-qualifier-list type-qualifier
parameter-list , parameter-declaration
parameter-declaration:
declaration-specifiers declarator
- declaration-specifiers abstract-declaratoropt
+ declaration-specifiers abstract-declarator<sub>opt</sub>
identifier-list:
identifier
- identifier-list , identifier</pre>
+ identifier-list , identifier
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
Each declarator declares one identifier, and asserts that when an operand of the same
<p><!--para 4 -->
In the following subclauses, consider a declaration
<pre>
- T D1</pre>
+ T D1
+</pre>
where T contains the declaration specifiers that specify a type T (such as int) and D1 is
a declarator that contains an identifier ident. The type specified for the identifier ident in
the various forms of declarator is described inductively using this notation.
<p><!--para 5 -->
If, in the declaration ''T D1'', D1 has the form
<pre>
- identifier</pre>
+ identifier
+</pre>
then the type specified for ident is T .
<p><!--para 6 -->
If, in the declaration ''T D1'', D1 has the form
<pre>
- ( D )</pre>
+ ( D )
+</pre>
then ident has the type specified by the declaration ''T D''. Thus, a declarator in
parentheses is identical to the unparenthesized declarator, but the binding of complicated
declarators may be altered by parentheses.
- Implementation limits
+<h6>Implementation limits</h6>
<p><!--para 7 -->
As discussed in <a href="#5.2.4.1">5.2.4.1</a>, an implementation may limit the number of pointer, array, and
function declarators that modify an arithmetic, structure, union, or void type, either
directly or via one or more typedefs.
<p><b> Forward references</b>: array declarators (<a href="#6.7.6.2">6.7.6.2</a>), type definitions (<a href="#6.7.8">6.7.8</a>).
-<a name="6.7.6.1" href="#6.7.6.1"><h5>6.7.6.1 Pointer declarators</h5></a>
+<h5><a name="6.7.6.1" href="#6.7.6.1">6.7.6.1 Pointer declarators</a></h5>
<h6>Semantics</h6>
<p><!--para 1 -->
If, in the declaration ''T D1'', D1 has the form
<pre>
- * type-qualifier-listopt D</pre>
+ * type-qualifier-list<sub>opt</sub> D
+</pre>
and the type specified for ident in the declaration ''T D'' is ''derived-declarator-type-list
T '', then the type specified for ident is ''derived-declarator-type-list type-qualifier-list
pointer to T ''. For each type qualifier in the list, ident is a so-qualified pointer.
<!--page 147 -->
<pre>
const int *ptr_to_constant;
- int *const constant_ptr;</pre>
+ int *const constant_ptr;
+</pre>
The contents of any object pointed to by ptr_to_constant shall not be modified through that pointer,
but ptr_to_constant itself may be changed to point to another object. Similarly, the contents of the
int pointed to by constant_ptr may be modified, but constant_ptr itself shall always point to the
type ''pointer to int''.
<pre>
typedef int *int_ptr;
- const int_ptr constant_ptr;</pre>
+ const int_ptr constant_ptr;
+</pre>
declares constant_ptr as an object that has type ''const-qualified pointer to int''.
-<a name="6.7.6.2" href="#6.7.6.2"><h5>6.7.6.2 Array declarators</h5></a>
+<h5><a name="6.7.6.2" href="#6.7.6.2">6.7.6.2 Array declarators</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
In addition to optional type qualifiers and the keyword static, the [ and ] may delimit
<p><!--para 3 -->
If, in the declaration ''T D1'', D1 has one of the forms:
<pre>
- D[ type-qualifier-listopt assignment-expressionopt ]
- D[ static type-qualifier-listopt assignment-expression ]
+ D[ type-qualifier-list<sub>opt</sub> assignment-expression<sub>opt</sub> ]
+ D[ static type-qualifier-list<sub>opt</sub> assignment-expression ]
D[ type-qualifier-list static assignment-expression ]
- D[ type-qualifier-listopt * ]</pre>
+ D[ type-qualifier-list<sub>opt</sub> * ]
+</pre>
and the type specified for ident in the declaration ''T D'' is ''derived-declarator-type-list
T '', then the type specified for ident is ''derived-declarator-type-list array of T ''.<sup><a href="#note142"><b>142)</b></a></sup>
(See <a href="#6.7.6.3">6.7.6.3</a> for the meaning of the optional type qualifiers and the keyword static.)
<p><!--para 7 -->
EXAMPLE 1
<pre>
- float fa[11], *afp[17];</pre>
+ float fa[11], *afp[17];
+</pre>
declares an array of float numbers and an array of pointers to float numbers.
<p><!--para 8 -->
EXAMPLE 2 Note the distinction between the declarations
<pre>
extern int *x;
- extern int y[];</pre>
+ extern int y[];
+</pre>
The first declares x to be a pointer to int; the second declares y to be an array of int of unspecified size
(an incomplete type), the storage for which is defined elsewhere.
p = a; // invalid: not compatible because 4 != 6
r = c; // compatible, but defined behavior only if
// n == 6 and m == n+1
- }</pre>
+ }
+</pre>
int (*s)[m]; // valid: auto pointer to VLA
extern int (*r)[m]; // invalid: r has linkage and points to VLA
static int (*q)[m] = &B; // valid: q is a static block pointer to VLA
- }</pre>
+ }
+</pre>
<p><b> Forward references</b>: function declarators (<a href="#6.7.6.3">6.7.6.3</a>), function definitions (<a href="#6.9.1">6.9.1</a>),
initialization (<a href="#6.7.9">6.7.9</a>).
<p><small><a name="note143" href="#note143">143)</a> Thus, * can be used only in function declarations that are not definitions (see <a href="#6.7.6.3">6.7.6.3</a>).
</small>
-<a name="6.7.6.3" href="#6.7.6.3"><h5>6.7.6.3 Function declarators (including prototypes)</h5></a>
+<h5><a name="6.7.6.3" href="#6.7.6.3">6.7.6.3 Function declarators (including prototypes)</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
A function declarator shall not specify a return type that is a function type or an array
If, in the declaration ''T D1'', D1 has the form
<!--page 150 -->
<pre>
- D( parameter-type-list )</pre>
+ D( parameter-type-list )
+</pre>
or
<pre>
- D( identifier-listopt )</pre>
+ D( identifier-list<sub>opt</sub> )
+</pre>
and the type specified for ident in the declaration ''T D'' is ''derived-declarator-type-list
T '', then the type specified for ident is ''derived-declarator-type-list function returning
T ''.
<p><!--para 16 -->
EXAMPLE 1 The declaration
<pre>
- int f(void), *fip(), (*pfi)();</pre>
+ int f(void), *fip(), (*pfi)();
+</pre>
declares a function f with no parameters returning an int, a function fip with no parameter specification
returning a pointer to an int, and a pointer pfi to a function with no parameter specification returning an
int. It is especially useful to compare the last two. The binding of *fip() is *(fip()), so that the
<p><!--para 18 -->
EXAMPLE 2 The declaration
<pre>
- int (*apfi[3])(int *x, int *y);</pre>
+ int (*apfi[3])(int *x, int *y);
+</pre>
declares an array apfi of three pointers to functions returning int. Each of these functions has two
parameters that are pointers to int. The identifiers x and y are declared for descriptive purposes only and
go out of scope at the end of the declaration of apfi.
<p><!--para 19 -->
EXAMPLE 3 The declaration
<pre>
- int (*fpfi(int (*)(long), int))(int, ...);</pre>
+ int (*fpfi(int (*)(long), int))(int, ...);
+</pre>
declares a function fpfi that returns a pointer to a function returning an int. The function fpfi has two
parameters: a pointer to a function returning an int (with one parameter of type long int), and an int.
The pointer returned by fpfi points to a function that has one int parameter and accepts zero or more
for (int j = 0, k = n*m+300; j < k; j++)
// a is a pointer to a VLA with n*m+300 elements
a[i][j] += x;
- }</pre>
+ }
+</pre>
<p><!--para 21 -->
EXAMPLE 5 The following are all compatible function prototype declarators.
double maximum(int n, int m, double a[n][m]);
double maximum(int n, int m, double a[*][*]);
double maximum(int n, int m, double a[ ][*]);
- double maximum(int n, int m, double a[ ][m]);</pre>
+ double maximum(int n, int m, double a[ ][m]);
+</pre>
as are:
<pre>
void f(double (* restrict a)[5]);
void f(double a[restrict][5]);
void f(double a[restrict 3][5]);
- void f(double a[restrict static 3][5]);</pre>
+ void f(double a[restrict static 3][5]);
+</pre>
(Note that the last declaration also specifies that the argument corresponding to a in any call to f must be a
non-null pointer to the first of at least three arrays of 5 doubles, which the others do not.)
<p><small><a name="note146" href="#note146">146)</a> If both function types are ''old style'', parameter types are not compared.
</small>
-<a name="6.7.7" href="#6.7.7"><h4>6.7.7 Type names</h4></a>
+<h4><a name="6.7.7" href="#6.7.7">6.7.7 Type names</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
type-name:
- specifier-qualifier-list abstract-declaratoropt
+ specifier-qualifier-list abstract-declarator<sub>opt</sub>
abstract-declarator:
pointer
- pointeropt direct-abstract-declarator
+ pointer<sub>opt</sub> direct-abstract-declarator
direct-abstract-declarator:
( abstract-declarator )
- direct-abstract-declaratoropt [ type-qualifier-listopt
- assignment-expressionopt ]
- direct-abstract-declaratoropt [ static type-qualifier-listopt
+ direct-abstract-declarator<sub>opt</sub> [ type-qualifier-list<sub>opt</sub>
+ assignment-expression<sub>opt</sub> ]
+ direct-abstract-declarator<sub>opt</sub> [ static type-qualifier-list<sub>opt</sub>
assignment-expression ]
- direct-abstract-declaratoropt [ type-qualifier-list static
+ direct-abstract-declarator<sub>opt</sub> [ type-qualifier-list static
assignment-expression ]
- direct-abstract-declaratoropt [ * ]
- direct-abstract-declaratoropt ( parameter-type-listopt )</pre>
+ direct-abstract-declarator<sub>opt</sub> [ * ]
+ direct-abstract-declarator<sub>opt</sub> ( parameter-type-list<sub>opt</sub> )
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
In several contexts, it is necessary to specify a type. This is accomplished using a type
(e) int (*)[*]
(f) int *()
(g) int (*)(void)
- (h) int (*const [])(unsigned int, ...)</pre>
+ (h) int (*const [])(unsigned int, ...)
+</pre>
name respectively the types (a) int, (b) pointer to int, (c) array of three pointers to int, (d) pointer to an
array of three ints, (e) pointer to a variable length array of an unspecified number of ints, (f) function
with no parameter specification returning a pointer to int, (g) pointer to function with no parameters
parameter specification'', rather than redundant parentheses around the omitted identifier.
</small>
-<a name="6.7.8" href="#6.7.8"><h4>6.7.8 Type definitions</h4></a>
+<h4><a name="6.7.8" href="#6.7.8">6.7.8 Type definitions</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
typedef-name:
- identifier</pre>
+ identifier
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
If a typedef name specifies a variably modified type then it shall have block scope.
synonym for the type so specified. That is, in the following declarations:
<pre>
typedef T type_ident;
- type_ident D;</pre>
+ type_ident D;
+</pre>
type_ident is defined as a typedef name with the type specified by the declaration
specifiers in T (known as T ), and the identifier in D has the type ''derived-declarator-
type-list T '' where the derived-declarator-type-list is specified by the declarators of D. A
EXAMPLE 1 After
<pre>
typedef int MILES, KLICKSP();
- typedef struct { double hi, lo; } range;</pre>
+ typedef struct { double hi, lo; } range;
+</pre>
the constructions
<pre>
MILES distance;
extern KLICKSP *metricp;
range x;
- range z, *zp;</pre>
+ range z, *zp;
+</pre>
are all valid declarations. The type of distance is int, that of metricp is ''pointer to function with no
parameter specification returning int'', and that of x and z is the specified structure; zp is a pointer to
such a structure. The object distance has a type compatible with any other int object.
EXAMPLE 2 After the declarations
<pre>
typedef struct s1 { int x; } t1, *tp1;
- typedef struct s2 { int x; } t2, *tp2;</pre>
+ typedef struct s2 { int x; } t2, *tp2;
+</pre>
type t1 and the type pointed to by tp1 are compatible. Type t1 is also compatible with type struct
s1, but not compatible with the types struct s2, t2, the type pointed to by tp2, or int.
<!--page 155 -->
unsigned t:4;
const t:5;
plain r:5;
- };</pre>
+ };
+</pre>
declare a typedef name t with type signed int, a typedef name plain with type int, and a structure
with three bit-field members, one named t that contains values in the range [0, 15], an unnamed const-
qualified bit-field which (if it could be accessed) would contain values in either the range [-15, +15] or
in an inner scope by
<pre>
t f(t (t));
- long t;</pre>
+ long t;
+</pre>
then a function f is declared with type ''function returning signed int with one unnamed parameter
with type pointer to function returning signed int with one unnamed parameter with type signed
int'', and an identifier t with type long int.
typedef void fv(int), (*pfv)(int);
void (*signal(int, void (*)(int)))(int);
fv *signal(int, fv *);
- pfv signal(int, pfv);</pre>
+ pfv signal(int, pfv);
+</pre>
<p><!--para 8 -->
EXAMPLE 5 If a typedef name denotes a variable length array type, the length of the array is fixed at the
int b[n]; // a and b are different sizes
for (int i = 1; i < n; i++)
a[i-1] = b[i];
- }</pre>
+ }
+</pre>
-<a name="6.7.9" href="#6.7.9"><h4>6.7.9 Initialization</h4></a>
+<h4><a name="6.7.9" href="#6.7.9">6.7.9 Initialization</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
{ initializer-list }
{ initializer-list , }
initializer-list:
- designationopt initializer
- initializer-list , designationopt initializer
+ designation<sub>opt</sub> initializer
+ initializer-list , designation<sub>opt</sub> initializer
designation:
designator-list =
designator-list:
designator-list designator
designator:
[ constant-expression ]
- . identifier</pre>
+ . identifier
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
No initializer shall attempt to provide a value for an object not contained within the entity
<p><!--para 6 -->
If a designator has the form
<pre>
- [ constant-expression ]</pre>
+ [ constant-expression ]
+</pre>
then the current object (defined below) shall have array type and the expression shall be
an integer constant expression. If the array is of unknown size, any nonnegative value is
valid.
<p><!--para 7 -->
If a designator has the form
<pre>
- . identifier</pre>
+ . identifier
+</pre>
then the current object (defined below) shall have structure or union type and the
identifier shall be the name of a member of that type.
<!--page 157 -->
EXAMPLE 1 Provided that <a href="#7.3"><complex.h></a> has been #included, the declarations
<pre>
int i = <a href="#3.5">3.5</a>;
- double complex c = 5 + 3 * I;</pre>
+ double complex c = 5 + 3 * I;
+</pre>
define and initialize i with the value 3 and c with the value 5.0 + i3.0.
<p><!--para 25 -->
EXAMPLE 2 The declaration
<pre>
- int x[] = { 1, 3, 5 };</pre>
+ int x[] = { 1, 3, 5 };
+</pre>
defines and initializes x as a one-dimensional array object that has three elements, as no size was specified
and there are three initializers.
{ 1, 3, 5 },
{ 2, 4, 6 },
{ 3, 5, 7 },
- };</pre>
+ };
+</pre>
is a definition with a fully bracketed initialization: 1, 3, and 5 initialize the first row of y (the array object
y[0]), namely y[0][0], y[0][1], and y[0][2]. Likewise the next two lines initialize y[1] and
y[2]. The initializer ends early, so y[3] is initialized with zeros. Precisely the same effect could have
<pre>
int y[4][3] = {
1, 3, 5, 2, 4, 6, 3, 5, 7
- };</pre>
+ };
+</pre>
The initializer for y[0] does not begin with a left brace, so three items from the list are used. Likewise the
next three are taken successively for y[1] and y[2].
<pre>
int z[4][3] = {
{ 1 }, { 2 }, { 3 }, { 4 }
- };</pre>
+ };
+</pre>
initializes the first column of z as specified and initializes the rest with zeros.
<p><!--para 28 -->
EXAMPLE 5 The declaration
<pre>
- struct { int a[3], b; } w[] = { { 1 }, 2 };</pre>
+ struct { int a[3], b; } w[] = { { 1 }, 2 };
+</pre>
is a definition with an inconsistently bracketed initialization. It defines an array with two element
{ 1 },
{ 2, 3 },
{ 4, 5, 6 }
- };</pre>
+ };
+</pre>
contains an incompletely but consistently bracketed initialization. It defines a three-dimensional array
object: q[0][0][0] is 1, q[1][0][0] is 2, q[1][0][1] is 3, and 4, 5, and 6 initialize
q[2][0][0], q[2][0][1], and q[2][1][0], respectively; all the rest are zero. The initializer for
1, 0, 0, 0, 0, 0,
2, 3, 0, 0, 0, 0,
4, 5, 6
- };</pre>
+ };
+</pre>
or by:
<pre>
short q[4][3][2] = {
{ 4, 5 },
{ 6 },
}
- };</pre>
+ };
+</pre>
in a fully bracketed form.
<p><!--para 30 -->
Note that the fully bracketed and minimally bracketed forms of initialization are, in general, less likely to
EXAMPLE 7 One form of initialization that completes array types involves typedef names. Given the
declaration
<pre>
- typedef int A[]; // OK - declared with block scope</pre>
+ typedef int A[]; // OK - declared with block scope
+</pre>
the declaration
<pre>
- A a = { 1, 2 }, b = { 3, 4, 5 };</pre>
+ A a = { 1, 2 }, b = { 3, 4, 5 };
+</pre>
is identical to
<pre>
- int a[] = { 1, 2 }, b[] = { 3, 4, 5 };</pre>
+ int a[] = { 1, 2 }, b[] = { 3, 4, 5 };
+</pre>
due to the rules for incomplete types.
<!--page 161 -->
<p><!--para 32 -->
EXAMPLE 8 The declaration
<pre>
- char s[] = "abc", t[3] = "abc";</pre>
+ char s[] = "abc", t[3] = "abc";
+</pre>
defines ''plain'' char array objects s and t whose elements are initialized with character string literals.
This declaration is identical to
<pre>
char s[] = { 'a', 'b', 'c', '\0' },
- t[] = { 'a', 'b', 'c' };</pre>
+ t[] = { 'a', 'b', 'c' };
+</pre>
The contents of the arrays are modifiable. On the other hand, the declaration
<pre>
- char *p = "abc";</pre>
+ char *p = "abc";
+</pre>
defines p with type ''pointer to char'' and initializes it to point to an object with type ''array of char''
with length 4 whose elements are initialized with a character string literal. If an attempt is made to use p to
modify the contents of the array, the behavior is undefined.
const char *nm[] = {
[member_two] = "member two",
[member_one] = "member one",
- };</pre>
+ };
+</pre>
<p><!--para 34 -->
EXAMPLE 10 Structure members can be initialized to nonzero values without depending on their order:
<pre>
- div_t answer = { .quot = 2, .rem = -1 };</pre>
+ div_t answer = { .quot = 2, .rem = -1 };
+</pre>
<p><!--para 35 -->
EXAMPLE 11 Designators can be used to provide explicit initialization when unadorned initializer lists
might be misunderstood:
<pre>
struct { int a[3], b; } w[] =
- { [0].a = {1}, [1].a[0] = 2 };</pre>
+ { [0].a = {1}, [1].a[0] = 2 };
+</pre>
<p><!--para 36 -->
EXAMPLE 12 Space can be ''allocated'' from both ends of an array by using a single designator:
-<p><!--para 37 -->
<pre>
int a[MAX] = {
1, 3, 5, 7, 9, [MAX-5] = 8, 6, 4, 2, 0
- };</pre>
+ };
+</pre>
+<p><!--para 37 -->
In the above, if MAX is greater than ten, there will be some zero-valued elements in the middle; if it is less
than ten, some of the values provided by the first five initializers will be overridden by the second five.
<p><!--para 38 -->
EXAMPLE 13 Any member of a union can be initialized:
<pre>
- union { /* ... */ } u = { .any_member = 42 };</pre>
+ union { /* ... */ } u = { .any_member = 42 };
+</pre>
<p><b> Forward references</b>: common definitions <a href="#7.19"><stddef.h></a> (<a href="#7.19">7.19</a>).
<!--page 162 -->
<p><small><a name="note152" href="#note152">152)</a> In particular, the evaluation order need not be the same as the order of subobject initialization.
</small>
-<a name="6.7.10" href="#6.7.10"><h4>6.7.10 Static assertions</h4></a>
+<h4><a name="6.7.10" href="#6.7.10">6.7.10 Static assertions</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
static_assert-declaration:
- _Static_assert ( constant-expression , string-literal ) ;</pre>
+ _Static_assert ( constant-expression , string-literal ) ;
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
The constant expression shall compare unequal to 0.
<p><b> Forward references</b>: diagnostics (<a href="#7.2">7.2</a>).
<!--page 163 -->
-<a name="6.8" href="#6.8"><h3>6.8 Statements and blocks</h3></a>
+<h3><a name="6.8" href="#6.8">6.8 Statements and blocks</a></h3>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
expression-statement
selection-statement
iteration-statement
- jump-statement</pre>
+ jump-statement
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
A statement specifies an action to be performed. Except as indicated, statements are
<p><b> Forward references</b>: expression and null statements (<a href="#6.8.3">6.8.3</a>), selection statements
(<a href="#6.8.4">6.8.4</a>), iteration statements (<a href="#6.8.5">6.8.5</a>), the return statement (<a href="#6.8.6.4">6.8.6.4</a>).
-<a name="6.8.1" href="#6.8.1"><h4>6.8.1 Labeled statements</h4></a>
+<h4><a name="6.8.1" href="#6.8.1">6.8.1 Labeled statements</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
labeled-statement:
identifier : statement
case constant-expression : statement
- default : statement</pre>
+ default : statement
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
A case or default label shall appear only in a switch statement. Further
them.
<p><b> Forward references</b>: the goto statement (<a href="#6.8.6.1">6.8.6.1</a>), the switch statement (<a href="#6.8.4.2">6.8.4.2</a>).
-<a name="6.8.2" href="#6.8.2"><h4>6.8.2 Compound statement</h4></a>
+<h4><a name="6.8.2" href="#6.8.2">6.8.2 Compound statement</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
compound-statement:
- { block-item-listopt }
+ { block-item-list<sub>opt</sub> }
block-item-list:
block-item
block-item-list block-item
block-item:
declaration
- statement</pre>
+ statement
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
A compound statement is a block.
-<a name="6.8.3" href="#6.8.3"><h4>6.8.3 Expression and null statements</h4></a>
+<h4><a name="6.8.3" href="#6.8.3">6.8.3 Expression and null statements</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
expression-statement:
- expressionopt ;</pre>
+ expression<sub>opt</sub> ;
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
The expression in an expression statement is evaluated as a void expression for its side
<pre>
int p(int);
/* ... */
- (void)p(0);</pre>
+ (void)p(0);
+</pre>
char *s;
/* ... */
while (*s++ != '\0')
- ;</pre>
+ ;
+</pre>
a null statement is used to supply an empty loop body to the iteration statement.
<p><!--para 6 -->
}
/* ... */
end_loop1: ;
- }</pre>
+ }
+</pre>
<p><b> Forward references</b>: iteration statements (<a href="#6.8.5">6.8.5</a>).
<p><small><a name="note153" href="#note153">153)</a> Such as assignments, and function calls which have side effects.
</small>
-<a name="6.8.4" href="#6.8.4"><h4>6.8.4 Selection statements</h4></a>
+<h4><a name="6.8.4" href="#6.8.4">6.8.4 Selection statements</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
selection-statement:
if ( expression ) statement
if ( expression ) statement else statement
- switch ( expression ) statement</pre>
+ switch ( expression ) statement
+</pre>
<h6>Semantics</h6>
<p><!--para 2 -->
A selection statement selects among a set of statements depending on the value of a
enclosing block. Each associated substatement is also a block whose scope is a strict
subset of the scope of the selection statement.
-<a name="6.8.4.1" href="#6.8.4.1"><h5>6.8.4.1 The if statement</h5></a>
+<h5><a name="6.8.4.1" href="#6.8.4.1">6.8.4.1 The if statement</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The controlling expression of an if statement shall have scalar type.
An else is associated with the lexically nearest preceding if that is allowed by the
syntax.
-<a name="6.8.4.2" href="#6.8.4.2"><h5>6.8.4.2 The switch statement</h5></a>
+<h5><a name="6.8.4.2" href="#6.8.4.2">6.8.4.2 The switch statement</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The controlling expression of a switch statement shall have integer type.
a default label, control jumps to the labeled statement. If no converted case constant
expression matches and there is no default label, no part of the switch body is
executed.
- Implementation limits
+<h6>Implementation limits</h6>
<p><!--para 6 -->
As discussed in <a href="#5.2.4.1">5.2.4.1</a>, the implementation may limit the number of case values in a
switch statement.
/* falls through into default code */
default:
printf("%d\n", i);
- }</pre>
+ }
+</pre>
the object whose identifier is i exists with automatic storage duration (within the block) but is never
initialized, and thus if the controlling expression has a nonzero value, the call to the printf function will
access an indeterminate value. Similarly, the call to the function f cannot be reached.
default label associated with the switch that is in the block containing the declaration.
</small>
-<a name="6.8.5" href="#6.8.5"><h4>6.8.5 Iteration statements</h4></a>
+<h4><a name="6.8.5" href="#6.8.5">6.8.5 Iteration statements</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
iteration-statement:
while ( expression ) statement
do statement while ( expression ) ;
- for ( expressionopt ; expressionopt ; expressionopt ) statement
- for ( declaration expressionopt ; expressionopt ) statement</pre>
+ for ( expression<sub>opt</sub> ; expression<sub>opt</sub> ; expression<sub>opt</sub> ) statement
+ for ( declaration expression<sub>opt</sub> ; expression<sub>opt</sub> ) statement
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
The controlling expression of an iteration statement shall have scalar type.
termination cannot be proven.
</small>
-<a name="6.8.5.1" href="#6.8.5.1"><h5>6.8.5.1 The while statement</h5></a>
+<h5><a name="6.8.5.1" href="#6.8.5.1">6.8.5.1 The while statement</a></h5>
<p><!--para 1 -->
The evaluation of the controlling expression takes place before each execution of the loop
body.
-<a name="6.8.5.2" href="#6.8.5.2"><h5>6.8.5.2 The do statement</h5></a>
+<h5><a name="6.8.5.2" href="#6.8.5.2">6.8.5.2 The do statement</a></h5>
<p><!--para 1 -->
The evaluation of the controlling expression takes place after each execution of the loop
body.
-<a name="6.8.5.3" href="#6.8.5.3"><h5>6.8.5.3 The for statement</h5></a>
+<h5><a name="6.8.5.3" href="#6.8.5.3">6.8.5.3 The for statement</a></h5>
<p><!--para 1 -->
The statement
<pre>
- for ( clause-1 ; expression-2 ; expression-3 ) statement</pre>
+ for ( clause-1 ; expression-2 ; expression-3 ) statement
+</pre>
behaves as follows: The expression expression-2 is the controlling expression that is
evaluated before each execution of the loop body. The expression expression-3 is
evaluated as a void expression after each execution of the loop body. If clause-1 is a
specifies an operation (such as incrementing) that is performed after each iteration.
</small>
-<a name="6.8.6" href="#6.8.6"><h4>6.8.6 Jump statements</h4></a>
+<h4><a name="6.8.6" href="#6.8.6">6.8.6 Jump statements</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
goto identifier ;
continue ;
break ;
- return expressionopt ;</pre>
+ return expression<sub>opt</sub> ;
+</pre>
<p><!--para 2 -->
A jump statement causes an unconditional jump to another place.
-<a name="6.8.6.1" href="#6.8.6.1"><h5>6.8.6.1 The goto statement</h5></a>
+<h5><a name="6.8.6.1" href="#6.8.6.1">6.8.6.1 The goto statement</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
The identifier in a goto statement shall name a label located somewhere in the enclosing
<li> The code to determine the next operation is at the head of the loop. (To allow it to be reached by
continue statements, for example.)
<!--page 170 -->
-</ol>
-<p><!--para 4 -->
<pre>
/* ... */
goto first_time;
}
// handle other operations
/* ... */
- }</pre>
+ }
+</pre>
+</ol>
+<p><!--para 4 -->
EXAMPLE 2 A goto statement is not allowed to jump past any declarations of objects with variably
modified types. A jump within the scope, however, is permitted.
<pre>
lab4:
a[j] = <a href="#6.6">6.6</a>;
}
- goto lab4; // invalid: going INTO scope of VLA.</pre>
+ goto lab4; // invalid: going INTO scope of VLA.
+</pre>
-<a name="6.8.6.2" href="#6.8.6.2"><h5>6.8.6.2 The continue statement</h5></a>
+<h5><a name="6.8.6.2" href="#6.8.6.2">6.8.6.2 The continue statement</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
A continue statement shall appear only in or as a loop body.
<pre>
/* ... */ /* ... */ /* ... */
continue; continue; continue;
- /* ... */ /* ... */ /* ... */</pre>
+ /* ... */ /* ... */ /* ... */
+</pre>
contin: ; contin: ; contin: ;
} } while (/* ... */); }
unless the continue statement shown is in an enclosed iteration statement (in which
<p><small><a name="note159" href="#note159">159)</a> Following the contin: label is a null statement.
</small>
-<a name="6.8.6.3" href="#6.8.6.3"><h5>6.8.6.3 The break statement</h5></a>
+<h5><a name="6.8.6.3" href="#6.8.6.3">6.8.6.3 The break statement</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
A break statement shall appear only in or as a switch body or loop body.
<!--page 171 -->
-<a name="6.8.6.4" href="#6.8.6.4"><h5>6.8.6.4 The return statement</h5></a>
+<h5><a name="6.8.6.4" href="#6.8.6.4">6.8.6.4 The return statement</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
A return statement with an expression shall not appear in a function whose return type
return g.u1.f2;
}
/* ... */
- g.u2.f3 = f();</pre>
+ g.u2.f3 = f();
+</pre>
there is no undefined behavior, although there would be if the assignment were done directly (without using
a function call to fetch the value).
or precision than implied by the type; a cast may be used to remove this extra range and precision.
</small>
-<a name="6.9" href="#6.9"><h3>6.9 External definitions</h3></a>
+<h3><a name="6.9" href="#6.9">6.9 External definitions</a></h3>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
translation-unit external-declaration
external-declaration:
function-definition
- declaration</pre>
+ declaration
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
The storage-class specifiers auto and register shall not appear in the declaration
external definition for it.
</small>
-<a name="6.9.1" href="#6.9.1"><h4>6.9.1 Function definitions</h4></a>
+<h4><a name="6.9.1" href="#6.9.1">6.9.1 Function definitions</a></h4>
<h6>Syntax</h6>
<p><!--para 1 -->
<pre>
function-definition:
- declaration-specifiers declarator declaration-listopt compound-statement
+ declaration-specifiers declarator declaration-list<sub>opt</sub> compound-statement
declaration-list:
declaration
- declaration-list declaration</pre>
+ declaration-list declaration
+</pre>
<h6>Constraints</h6>
<p><!--para 2 -->
The identifier declared in a function definition (which is the name of the function) shall
extern int max(int a, int b)
{
return a > b ? a : b;
- }</pre>
+ }
+</pre>
extern is the storage-class specifier and int is the type specifier; max(int a, int b) is the
function declarator; and
<pre>
- { return a > b ? a : b; }</pre>
+ { return a > b ? a : b; }
+</pre>
is the function body. The following similar definition uses the identifier-list form for the parameter
declarations:
int a, b;
{
return a > b ? a : b;
- }</pre>
+ }
+</pre>
Here int a, b; is the declaration list for the parameters. The difference between these two definitions is
that the first form acts as a prototype declaration that forces conversion of the arguments of subsequent calls
to the function, whereas the second form does not.
<pre>
int f(void);
/* ... */
- g(f);</pre>
+ g(f);
+</pre>
Then the definition of g might read
<pre>
void g(int (*funcp)(void))
{
/* ... */
(*funcp)(); /* or funcp(); ... */
- }</pre>
+ }
+</pre>
or, equivalently,
<pre>
void g(int func(void))
{
/* ... */
func(); /* or (*func)(); ... */
- }</pre>
+ }
+</pre>
<h6>footnotes</h6>
F *e(void) { /* ... */ } // e returns a pointer to a function
F *((e))(void) { /* ... */ } // same: parentheses irrelevant
int (*fp)(void); // fp points to a function that has type F
- F *Fp; // Fp points to a function that has type F</pre>
+ F *Fp; // Fp points to a function that has type F
+</pre>
</small>
<p><small><a name="note163" href="#note163">163)</a> See ''future language directions'' (<a href="#6.11.7">6.11.7</a>).
</small>
<p><small><a name="note164" href="#note164">164)</a> A parameter identifier cannot be redeclared in the function body except in an enclosed block.
</small>
-<a name="6.9.2" href="#6.9.2"><h4>6.9.2 External object definitions</h4></a>
+<h4><a name="6.9.2" href="#6.9.2">6.9.2 External object definitions</a></h4>
<h6>Semantics</h6>
<p><!--para 1 -->
If the declaration of an identifier for an object has file scope and an initializer, the
extern int i2; // refers to previous, whose linkage is internal
extern int i3; // refers to previous, whose linkage is external
extern int i4; // refers to previous, whose linkage is external
- extern int i5; // refers to previous, whose linkage is internal</pre>
+ extern int i5; // refers to previous, whose linkage is internal
+</pre>
<p><!--para 5 -->
EXAMPLE 2 If at the end of the translation unit containing
<pre>
- int i[];</pre>
+ int i[];
+</pre>
the array i still has incomplete type, the implicit initializer causes it to have one element, which is set to
zero on program startup.
<!--page 177 -->
-<a name="6.10" href="#6.10"><h3>6.10 Preprocessing directives</h3></a>
+<h3><a name="6.10" href="#6.10">6.10 Preprocessing directives</a></h3>
<h6>Syntax</h6>
<p><!--para 1 -->
<!--page 178 -->
<pre>
preprocessing-file:
- groupopt
+ group<sub>opt</sub>
group:
group-part
group group-part
text-line
# non-directive
if-section:
- if-group elif-groupsopt else-groupopt endif-line
+ if-group elif-groups<sub>opt</sub> else-group<sub>opt</sub> endif-line
if-group:
- # if constant-expression new-line groupopt
- # ifdef identifier new-line groupopt
- # ifndef identifier new-line groupopt
+ # if constant-expression new-line group<sub>opt</sub>
+ # ifdef identifier new-line group<sub>opt</sub>
+ # ifndef identifier new-line group<sub>opt</sub>
elif-groups:
elif-group
elif-groups elif-group
elif-group:
- # elif constant-expression new-line groupopt
+ # elif constant-expression new-line group<sub>opt</sub>
else-group:
- # else new-line groupopt
+ # else new-line group<sub>opt</sub>
endif-line:
# endif new-line
control-line:
# include pp-tokens new-line
# define identifier replacement-list new-line
- # define identifier lparen identifier-listopt )
+ # define identifier lparen identifier-list<sub>opt</sub> )
replacement-list new-line
# define identifier lparen ... ) replacement-list new-line
# define identifier lparen identifier-list , ... )
replacement-list new-line
# undef identifier new-line
# line pp-tokens new-line
- # error pp-tokensopt new-line
- # pragma pp-tokensopt new-line
+ # error pp-tokens<sub>opt</sub> new-line
+ # pragma pp-tokens<sub>opt</sub> new-line
# new-line
text-line:
- pp-tokensopt new-line
+ pp-tokens<sub>opt</sub> new-line
non-directive:
pp-tokens new-line
lparen:
a ( character not immediately preceded by white-space
replacement-list:
- pp-tokensopt
+ pp-tokens<sub>opt</sub>
pp-tokens:
preprocessing-token
pp-tokens preprocessing-token
new-line:
- the new-line character</pre>
+ the new-line character
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A preprocessing directive consists of a sequence of preprocessing tokens that satisfies the
EXAMPLE In:
<pre>
#define EMPTY
- EMPTY # include <file.h></pre>
+ EMPTY # include <file.h>
+</pre>
the sequence of preprocessing tokens on the second line is not a preprocessing directive, because it does not
begin with a # at the start of translation phase 4, even though it will do so after the macro EMPTY has been
replaced.
# character string literal creation operator in <a href="#6.10.3.2">6.10.3.2</a>, for example).
</small>
-<a name="6.10.1" href="#6.10.1"><h4>6.10.1 Conditional inclusion</h4></a>
+<h4><a name="6.10.1" href="#6.10.1">6.10.1 Conditional inclusion</a></h4>
<h6>Constraints</h6>
<p><!--para 1 -->
The expression that controls conditional inclusion shall be an integer constant expression
except that: identifiers (including those lexically identical to keywords) are interpreted as *
described below;<sup><a href="#note166"><b>166)</b></a></sup> and it may contain unary operator expressions of the form
<pre>
- defined identifier</pre>
+ defined identifier
+</pre>
or
<pre>
- defined ( identifier )</pre>
+ defined ( identifier )
+</pre>
which evaluate to 1 if the identifier is currently defined as a macro name (that is, if it is
<p><!--para 3 -->
Preprocessing directives of the forms
<pre>
- # if constant-expression new-line groupopt
- # elif constant-expression new-line groupopt</pre>
+ # if constant-expression new-line group<sub>opt</sub>
+ # elif constant-expression new-line group<sub>opt</sub>
+</pre>
check whether the controlling constant expression evaluates to nonzero.
<p><!--para 4 -->
Prior to evaluation, macro invocations in the list of preprocessing tokens that will become
<p><!--para 5 -->
Preprocessing directives of the forms
<pre>
- # ifdef identifier new-line groupopt
- # ifndef identifier new-line groupopt</pre>
+ # ifdef identifier new-line group<sub>opt</sub>
+ # ifndef identifier new-line group<sub>opt</sub>
+</pre>
check whether the identifier is or is not currently defined as a macro name. Their
conditions are equivalent to #if defined identifier and #if !defined identifier
respectively.
including within a preprocessing directive.
</small>
-<a name="6.10.2" href="#6.10.2"><h4>6.10.2 Source file inclusion</h4></a>
+<h4><a name="6.10.2" href="#6.10.2">6.10.2 Source file inclusion</a></h4>
<h6>Constraints</h6>
<p><!--para 1 -->
A #include directive shall identify a header or source file that can be processed by the
<p><!--para 2 -->
A preprocessing directive of the form
<pre>
- # include <h-char-sequence> new-line</pre>
+ # include <h-char-sequence> new-line
+</pre>
searches a sequence of implementation-defined places for a header identified uniquely by
the specified sequence between the < and > delimiters, and causes the replacement of that
directive by the entire contents of the header. How the places are specified or the header
<p><!--para 3 -->
A preprocessing directive of the form
<pre>
- # include "q-char-sequence" new-line</pre>
+ # include "q-char-sequence" new-line
+</pre>
causes the replacement of that directive by the entire contents of the source file identified
by the specified sequence between the " delimiters. The named source file is searched
for in an implementation-defined manner. If this search is not supported, or if the search
fails, the directive is reprocessed as if it read
<pre>
- # include <h-char-sequence> new-line</pre>
+ # include <h-char-sequence> new-line
+</pre>
with the identical contained sequence (including > characters, if any) from the original
directive.
<p><!--para 4 -->
A preprocessing directive of the form
<pre>
- # include pp-tokens new-line</pre>
+ # include pp-tokens new-line
+</pre>
(that does not match one of the two previous forms) is permitted. The preprocessing
tokens after include in the directive are processed just as in normal text. (Each
identifier currently defined as a macro name is replaced by its replacement list of
EXAMPLE 1 The most common uses of #include preprocessing directives are as in the following:
<pre>
#include <a href="#7.21"><stdio.h></a>
- #include "myprog.h"</pre>
+ #include "myprog.h"
+</pre>
#else
#define INCFILE "versN.h"
#endif
- #include INCFILE</pre>
+ #include INCFILE
+</pre>
<p><b> Forward references</b>: macro replacement (<a href="#6.10.3">6.10.3</a>).
phases in <a href="#5.1.1.2">5.1.1.2</a>); thus, an expansion that results in two string literals is an invalid directive.
</small>
-<a name="6.10.3" href="#6.10.3"><h4>6.10.3 Macro replacement</h4></a>
+<h4><a name="6.10.3" href="#6.10.3">6.10.3 Macro replacement</a></h4>
<h6>Constraints</h6>
<p><!--para 1 -->
Two replacement lists are identical if and only if the preprocessing tokens in both have
<p><!--para 9 -->
A preprocessing directive of the form
<pre>
- # define identifier replacement-list new-line</pre>
+ # define identifier replacement-list new-line
+</pre>
defines an object-like macro that causes each subsequent instance of the macro name<sup><a href="#note171"><b>171)</b></a></sup>
to be replaced by the replacement list of preprocessing tokens that constitute the
remainder of the directive. The replacement list is then rescanned for more macro names
<p><!--para 10 -->
A preprocessing directive of the form
<pre>
- # define identifier lparen identifier-listopt ) replacement-list new-line
+ # define identifier lparen identifier-list<sub>opt</sub> ) replacement-list new-line
# define identifier lparen ... ) replacement-list new-line
- # define identifier lparen identifier-list , ... ) replacement-list new-line</pre>
+ # define identifier lparen identifier-list , ... ) replacement-list new-line
+</pre>
defines a function-like macro with parameters, whose use is similar syntactically to a
function call. The parameters are specified by the optional list of identifiers, whose scope
extends from their declaration in the identifier list until the new-line character that
<p><small><a name="note172" href="#note172">172)</a> Despite the name, a non-directive is a preprocessing directive.
</small>
-<a name="6.10.3.1" href="#6.10.3.1"><h5>6.10.3.1 Argument substitution</h5></a>
+<h5><a name="6.10.3.1" href="#6.10.3.1">6.10.3.1 Argument substitution</a></h5>
<p><!--para 1 -->
After the arguments for the invocation of a function-like macro have been identified,
argument substitution takes place. A parameter in the replacement list, unless preceded
were a parameter, and the variable arguments shall form the preprocessing tokens used to
replace it.
-<a name="6.10.3.2" href="#6.10.3.2"><h5>6.10.3.2 The # operator</h5></a>
+<h5><a name="6.10.3.2" href="#6.10.3.2">6.10.3.2 The # operator</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
Each # preprocessing token in the replacement list for a function-like macro shall be
## operators is unspecified.
<!--page 186 -->
-<a name="6.10.3.3" href="#6.10.3.3"><h5>6.10.3.3 The ## operator</h5></a>
+<h5><a name="6.10.3.3" href="#6.10.3.3">6.10.3.3 The ## operator</a></h5>
<h6>Constraints</h6>
<p><!--para 1 -->
A ## preprocessing token shall not occur at the beginning or at the end of a replacement
#define in_between(a) mkstr(a)
#define join(c, d) in_between(c hash_hash d)
char p[] = join(x, y); // equivalent to
- // char p[] = "x ## y";</pre>
+ // char p[] = "x ## y";
+</pre>
The expansion produces, at various stages:
<pre>
join(x, y)
in_between(x hash_hash y)
in_between(x ## y)
mkstr(x ## y)
- "x ## y"</pre>
+ "x ## y"
+</pre>
In other words, expanding hash_hash produces a new token, consisting of two adjacent sharp signs, but
this new token is not the ## operator.
exist only within translation phase 4.
</small>
-<a name="6.10.3.4" href="#6.10.3.4"><h5>6.10.3.4 Rescanning and further replacement</h5></a>
+<h5><a name="6.10.3.4" href="#6.10.3.4">6.10.3.4 Rescanning and further replacement</a></h5>
<p><!--para 1 -->
After all parameters in the replacement list have been substituted and # and ##
processing has taken place, all placemarker preprocessing tokens are removed. The
as a preprocessing directive even if it resembles one, but all pragma unary operator
expressions within it are then processed as specified in <a href="#6.10.9">6.10.9</a> below.
-<a name="6.10.3.5" href="#6.10.3.5"><h5>6.10.3.5 Scope of macro definitions</h5></a>
+<h5><a name="6.10.3.5" href="#6.10.3.5">6.10.3.5 Scope of macro definitions</a></h5>
<p><!--para 1 -->
A macro definition lasts (independent of block structure) until a corresponding #undef
directive is encountered or (if none is encountered) until the end of the preprocessing
<p><!--para 2 -->
A preprocessing directive of the form
<pre>
- # undef identifier new-line</pre>
+ # undef identifier new-line
+</pre>
causes the specified identifier no longer to be defined as a macro name. It is ignored if
the specified identifier is not currently defined as a macro name.
<p><!--para 3 -->
EXAMPLE 1 The simplest use of this facility is to define a ''manifest constant'', as in
<pre>
#define TABSIZE 100
- int table[TABSIZE];</pre>
+ int table[TABSIZE];
+</pre>
<p><!--para 4 -->
EXAMPLE 2 The following defines a function-like macro whose value is the maximum of its arguments.
arguments a second time (including side effects) and generating more code than a function if invoked
several times. It also cannot have its address taken, as it has none.
<pre>
- #define max(a, b) ((a) > (b) ? (a) : (b))</pre>
+ #define max(a, b) ((a) > (b) ? (a) : (b))
+</pre>
The parentheses ensure that the arguments and the resulting expression are bound properly.
<!--page 188 -->
<p><!--para 5 -->
g(x+(3,4)-w) | h 5) & m
(f)^m(m);
p() i[q()] = { q(1), r(2,3), r(4,), r(,5), r(,) };
- char c[2][6] = { str(hello), str() };</pre>
+ char c[2][6] = { str(hello), str() };
+</pre>
results in
<pre>
f(2 * (y+1)) + f(2 * (f(2 * (z[0])))) % f(2 * (0)) + t(1);
f(2 * (2+(3,4)-0,1)) | f(2 * (~ 5)) & f(2 * (0,1))^m(0,1);
int i[] = { 1, 23, 4, 5, };
- char c[2][6] = { "hello", "" };</pre>
+ char c[2][6] = { "hello", "" };
+</pre>
<p><!--para 6 -->
EXAMPLE 4 To illustrate the rules for creating character string literals and concatenating tokens, the
== 0) str(: @\n), s);
#include xstr(INCFILE(2).h)
glue(HIGH, LOW);
- xglue(HIGH, LOW)</pre>
+ xglue(HIGH, LOW)
+</pre>
results in
<!--page 189 -->
<pre>
s);
#include "vers2.h" (after macro replacement, before file access)
"hello";
- "hello" ", world"</pre>
+ "hello" ", world"
+</pre>
or, after concatenation of the character string literals,
<pre>
printf("x1= %d, x2= %s", x1, x2);
s);
#include "vers2.h" (after macro replacement, before file access)
"hello";
- "hello, world"</pre>
+ "hello, world"
+</pre>
Space around the # and ## tokens in the macro definition is optional.
<p><!--para 7 -->
<pre>
#define t(x,y,z) x ## y ## z
int j[] = { t(1,2,3), t(,4,5), t(6,,7), t(8,9,),
- t(10,,), t(,11,), t(,,12), t(,,) };</pre>
+ t(10,,), t(,11,), t(,,12), t(,,) };
+</pre>
results in
<pre>
int j[] = { 123, 45, 67, 89,
- 10, 11, 12, };</pre>
+ 10, 11, 12, };
+</pre>
<p><!--para 8 -->
EXAMPLE 6 To demonstrate the redefinition rules, the following sequence is valid.
#define FUNC_LIKE(a) ( a )
#define FUNC_LIKE( a )( /* note the white space */ \
a /* other stuff on this line
- */ )</pre>
+ */ )
+</pre>
But the following redefinitions are invalid:
<pre>
#define OBJ_LIKE (0) // different token sequence
#define OBJ_LIKE (1 - 1) // different white space
#define FUNC_LIKE(b) ( a ) // different parameter usage
- #define FUNC_LIKE(b) ( b ) // different parameter spelling</pre>
+ #define FUNC_LIKE(b) ( b ) // different parameter spelling
+</pre>
<p><!--para 9 -->
EXAMPLE 7 Finally, to show the variable argument list macro facilities:
debug("Flag");
debug("X = %d\n", x);
showlist(The first, second, and third items.);
- report(x>y, "x is %d but y is %d", x, y);</pre>
+ report(x>y, "x is %d but y is %d", x, y);
+</pre>
results in
<pre>
fprintf(stderr, "Flag" );
fprintf(stderr, "X = %d\n", x );
puts( "The first, second, and third items." );
((x>y)?puts("x>y"):
- printf("x is %d but y is %d", x, y));</pre>
+ printf("x is %d but y is %d", x, y));
+</pre>
-<a name="6.10.4" href="#6.10.4"><h4>6.10.4 Line control</h4></a>
+<h4><a name="6.10.4" href="#6.10.4">6.10.4 Line control</a></h4>
<h6>Constraints</h6>
<p><!--para 1 -->
The string literal of a #line directive, if present, shall be a character string literal.
<p><!--para 3 -->
A preprocessing directive of the form
<pre>
- # line digit-sequence new-line</pre>
+ # line digit-sequence new-line
+</pre>
causes the implementation to behave as if the following sequence of source lines begins
with a source line that has a line number as specified by the digit sequence (interpreted as
a decimal integer). The digit sequence shall not specify zero, nor a number greater than
<p><!--para 4 -->
A preprocessing directive of the form
<pre>
- # line digit-sequence "s-char-sequenceopt" new-line</pre>
+ # line digit-sequence "s-char-sequenceopt" new-line
+</pre>
sets the presumed line number similarly and changes the presumed name of the source
file to be the contents of the character string literal.
<p><!--para 5 -->
A preprocessing directive of the form
<pre>
- # line pp-tokens new-line</pre>
+ # line pp-tokens new-line
+</pre>
(that does not match one of the two previous forms) is permitted. The preprocessing
tokens after line on the directive are processed just as in normal text (each identifier
currently defined as a macro name is replaced by its replacement list of preprocessing
previous forms and is then processed as appropriate.
<!--page 191 -->
-<a name="6.10.5" href="#6.10.5"><h4>6.10.5 Error directive</h4></a>
+<h4><a name="6.10.5" href="#6.10.5">6.10.5 Error directive</a></h4>
<h6>Semantics</h6>
<p><!--para 1 -->
A preprocessing directive of the form
<pre>
- # error pp-tokensopt new-line</pre>
+ # error pp-tokens<sub>opt</sub> new-line
+</pre>
causes the implementation to produce a diagnostic message that includes the specified
sequence of preprocessing tokens.
-<a name="6.10.6" href="#6.10.6"><h4>6.10.6 Pragma directive</h4></a>
+<h4><a name="6.10.6" href="#6.10.6">6.10.6 Pragma directive</a></h4>
<h6>Semantics</h6>
<p><!--para 1 -->
A preprocessing directive of the form
<pre>
- # pragma pp-tokensopt new-line</pre>
+ # pragma pp-tokens<sub>opt</sub> new-line
+</pre>
where the preprocessing token STDC does not immediately follow pragma in the
directive (prior to any macro replacement)<sup><a href="#note174"><b>174)</b></a></sup> causes the implementation to behave in an
implementation-defined manner. The behavior might cause translation to fail or cause the
#pragma STDC FENV_ACCESS on-off-switch
#pragma STDC CX_LIMITED_RANGE on-off-switch
on-off-switch: one of
- ON OFF DEFAULT</pre>
+ ON OFF DEFAULT
+</pre>
<p><b> Forward references</b>: the FP_CONTRACT pragma (<a href="#7.12.2">7.12.2</a>), the FENV_ACCESS pragma
(<a href="#7.6.1">7.6.1</a>), the CX_LIMITED_RANGE pragma (<a href="#7.3.4">7.3.4</a>).
<p><small><a name="note175" href="#note175">175)</a> See ''future language directions'' (<a href="#6.11.8">6.11.8</a>).
</small>
-<a name="6.10.7" href="#6.10.7"><h4>6.10.7 Null directive</h4></a>
+<h4><a name="6.10.7" href="#6.10.7">6.10.7 Null directive</a></h4>
<h6>Semantics</h6>
<p><!--para 1 -->
A preprocessing directive of the form
<pre>
- # new-line</pre>
+ # new-line
+</pre>
has no effect.
-<a name="6.10.8" href="#6.10.8"><h4>6.10.8 Predefined macro names</h4></a>
+<h4><a name="6.10.8" href="#6.10.8">6.10.8 Predefined macro names</a></h4>
<p><!--para 1 -->
The values of the predefined macros listed in the following subclauses<sup><a href="#note176"><b>176)</b></a></sup> (except for
__FILE__ and __LINE__) remain constant throughout the translation unit.
<p><small><a name="note176" href="#note176">176)</a> See ''future language directions'' (<a href="#6.11.9">6.11.9</a>).
</small>
-<a name="6.10.8.1" href="#6.10.8.1"><h5>6.10.8.1 Mandatory macros</h5></a>
+<h5><a name="6.10.8.1" href="#6.10.8.1">6.10.8.1 Mandatory macros</a></h5>
<p><!--para 1 -->
The following macro names shall be defined by the implementation:
__DATE__ The date of translation of the preprocessing translation unit: a character
months are the same as those generated by the asctime function, and the
first character of dd is a space character if the value is less than 10. If the
date of translation is not available, an implementation-defined valid date
- shall be supplied.</pre>
+ shall be supplied.
+</pre>
__FILE__ The presumed name of the current source file (a character string literal).<sup><a href="#note177"><b>177)</b></a></sup>
__LINE__ The presumed line number (within the current source file) of the current
<pre>
- source line (an integer constant).177)</pre>
+ source line (an integer constant).<sup><a href="#note177"><b>177)</b></a></sup>
+</pre>
__STDC__ The integer constant 1, intended to indicate a conforming implementation.
__STDC_HOSTED__ The integer constant 1 if the implementation is a hosted
<pre>
- implementation or the integer constant 0 if it is not.</pre>
+ implementation or the integer constant 0 if it is not.
+</pre>
<pre>
string literal of the form "hh:mm:ss" as in the time generated by the
asctime function. If the time of translation is not available, an
- implementation-defined valid time shall be supplied.</pre>
+ implementation-defined valid time shall be supplied.
+</pre>
<p><b> Forward references</b>: the asctime function (<a href="#7.26.3.1">7.26.3.1</a>).
<h6>footnotes</h6>
Standard.
</small>
-<a name="6.10.8.2" href="#6.10.8.2"><h5>6.10.8.2 Environment macros</h5></a>
+<h5><a name="6.10.8.2" href="#6.10.8.2">6.10.8.2 Environment macros</a></h5>
<p><!--para 1 -->
The following macro names are conditionally defined by the implementation:
__STDC_ISO_10646__ An integer constant of the form yyyymmL (for example,
consists of all the characters that are defined by ISO/IEC 10646, along with
all amendments and technical corrigenda, as of the specified year and
month. If some other encoding is used, the macro shall not be defined and
- the actual encoding used is implementation-defined.</pre>
+ the actual encoding used is implementation-defined.
+</pre>
__STDC_MB_MIGHT_NEQ_WC__ The integer constant 1, intended to indicate that, in
<pre>
the encoding for wchar_t, a member of the basic character set need not
have a code value equal to its value when used as the lone character in an
- integer character constant.</pre>
+ integer character constant.
+</pre>
__STDC_UTF_16__ The integer constant 1, intended to indicate that values of type
<pre>
char16_t are UTF-16 encoded. If some other encoding is used, the
macro shall not be defined and the actual encoding used is implementation-
- defined.</pre>
+ defined.
+</pre>
__STDC_UTF_32__ The integer constant 1, intended to indicate that values of type
<pre>
char32_t are UTF-32 encoded. If some other encoding is used, the
macro shall not be defined and the actual encoding used is implementation-
- defined.</pre>
+ defined.
+</pre>
<p><b> Forward references</b>: common definitions (<a href="#7.19">7.19</a>), unicode utilities (<a href="#7.27">7.27</a>).
<!--page 194 -->
-<a name="6.10.8.3" href="#6.10.8.3"><h5>6.10.8.3 Conditional feature macros</h5></a>
+<h5><a name="6.10.8.3" href="#6.10.8.3">6.10.8.3 Conditional feature macros</a></h5>
<p><!--para 1 -->
The following macro names are conditionally defined by the implementation:
__STDC_ANALYZABLE__ The integer constant 1, intended to indicate conformance to
<pre>
- the specifications in <a href="#L">annex L</a> (Analyzability).</pre>
+ the specifications in <a href="#L">annex L</a> (Analyzability).
+</pre>
__STDC_IEC_559__ The integer constant 1, intended to indicate conformance to the
<pre>
- specifications in <a href="#F">annex F</a> (IEC 60559 floating-point arithmetic).</pre>
+ specifications in <a href="#F">annex F</a> (IEC 60559 floating-point arithmetic).
+</pre>
__STDC_IEC_559_COMPLEX__ The integer constant 1, intended to indicate
<pre>
adherence to the specifications in <a href="#G">annex G</a> (IEC 60559 compatible complex
- arithmetic).</pre>
+ arithmetic).
+</pre>
__STDC_LIB_EXT1__ The integer constant 201ymmL, intended to indicate support
<pre>
- for the extensions defined in <a href="#K">annex K</a> (Bounds-checking interfaces).<sup><a href="#note179"><b>179)</b></a></sup></pre>
+ for the extensions defined in <a href="#K">annex K</a> (Bounds-checking interfaces).<sup><a href="#note179"><b>179)</b></a></sup>
+</pre>
__STDC_NO_COMPLEX__ The integer constant 1, intended to indicate that the
<pre>
implementation does not support complex types or the <a href="#7.3"><complex.h></a>
- header.</pre>
+ header.
+</pre>
__STDC_NO_THREADS__ The integer constant 1, intended to indicate that the
<pre>
implementation does not support atomic types (including the _Atomic
type qualifier and the <a href="#7.17"><stdatomic.h></a> header) or the <a href="#7.25"><threads.h></a>
- header.</pre>
+ header.
+</pre>
__STDC_NO_VLA__ The integer constant 1, intended to indicate that the
-<p><!--para 2 -->
<pre>
implementation does not support variable length arrays or variably
- modified types.</pre>
+ modified types.
+</pre>
+<p><!--para 2 -->
An implementation that defines __STDC_NO_COMPLEX__ shall not define
__STDC_IEC_559_COMPLEX__.
each revision of this International Standard.
</small>
-<a name="6.10.9" href="#6.10.9"><h4>6.10.9 Pragma operator</h4></a>
+<h4><a name="6.10.9" href="#6.10.9">6.10.9 Pragma operator</a></h4>
<h6>Semantics</h6>
<p><!--para 1 -->
A unary operator expression of the form:
<pre>
- _Pragma ( string-literal )</pre>
+ _Pragma ( string-literal )
+</pre>
is processed as follows: The string literal is destringized by deleting the L prefix, if
present, deleting the leading and trailing double-quotes, replacing each escape sequence
\" by a double-quote, and replacing each escape sequence \\ by a single backslash. The
<p><!--para 2 -->
EXAMPLE A directive of the form:
<pre>
- #pragma listing on "..\listing.dir"</pre>
+ #pragma listing on "..\listing.dir"
+</pre>
can also be expressed as:
<pre>
- _Pragma ( "listing on \"..\\listing.dir\"" )</pre>
+ _Pragma ( "listing on \"..\\listing.dir\"" )
+</pre>
The latter form is processed in the same way whether it appears literally as shown, or results from macro
replacement, as in:
<!--page 196 -->
<pre>
#define LISTING(x) PRAGMA(listing on #x)
#define PRAGMA(x) _Pragma(#x)
- LISTING ( ..\listing.dir )</pre>
+ LISTING ( ..\listing.dir )
+</pre>
-<a name="6.11" href="#6.11"><h3>6.11 Future language directions</h3></a>
+<h3><a name="6.11" href="#6.11">6.11 Future language directions</a></h3>
-<a name="6.11.1" href="#6.11.1"><h4>6.11.1 Floating types</h4></a>
+<h4><a name="6.11.1" href="#6.11.1">6.11.1 Floating types</a></h4>
<p><!--para 1 -->
Future standardization may include additional floating-point types, including those with
greater range, precision, or both than long double.
-<a name="6.11.2" href="#6.11.2"><h4>6.11.2 Linkages of identifiers</h4></a>
+<h4><a name="6.11.2" href="#6.11.2">6.11.2 Linkages of identifiers</a></h4>
<p><!--para 1 -->
Declaring an identifier with internal linkage at file scope without the static storage-
class specifier is an obsolescent feature.
-<a name="6.11.3" href="#6.11.3"><h4>6.11.3 External names</h4></a>
+<h4><a name="6.11.3" href="#6.11.3">6.11.3 External names</a></h4>
<p><!--para 1 -->
Restriction of the significance of an external name to fewer than 255 characters
(considering each universal character name or extended source character as a single
character) is an obsolescent feature that is a concession to existing implementations.
-<a name="6.11.4" href="#6.11.4"><h4>6.11.4 Character escape sequences</h4></a>
+<h4><a name="6.11.4" href="#6.11.4">6.11.4 Character escape sequences</a></h4>
<p><!--para 1 -->
Lowercase letters as escape sequences are reserved for future standardization. Other
characters may be used in extensions.
-<a name="6.11.5" href="#6.11.5"><h4>6.11.5 Storage-class specifiers</h4></a>
+<h4><a name="6.11.5" href="#6.11.5">6.11.5 Storage-class specifiers</a></h4>
<p><!--para 1 -->
The placement of a storage-class specifier other than at the beginning of the declaration
specifiers in a declaration is an obsolescent feature.
-<a name="6.11.6" href="#6.11.6"><h4>6.11.6 Function declarators</h4></a>
+<h4><a name="6.11.6" href="#6.11.6">6.11.6 Function declarators</a></h4>
<p><!--para 1 -->
The use of function declarators with empty parentheses (not prototype-format parameter
type declarators) is an obsolescent feature.
-<a name="6.11.7" href="#6.11.7"><h4>6.11.7 Function definitions</h4></a>
+<h4><a name="6.11.7" href="#6.11.7">6.11.7 Function definitions</a></h4>
<p><!--para 1 -->
The use of function definitions with separate parameter identifier and declaration lists
(not prototype-format parameter type and identifier declarators) is an obsolescent feature.
-<a name="6.11.8" href="#6.11.8"><h4>6.11.8 Pragma directives</h4></a>
+<h4><a name="6.11.8" href="#6.11.8">6.11.8 Pragma directives</a></h4>
<p><!--para 1 -->
Pragmas whose first preprocessing token is STDC are reserved for future standardization.
-<a name="6.11.9" href="#6.11.9"><h4>6.11.9 Predefined macro names</h4></a>
+<h4><a name="6.11.9" href="#6.11.9">6.11.9 Predefined macro names</a></h4>
<p><!--para 1 -->
Macro names beginning with __STDC_ are reserved for future standardization.
<!--page 197 -->
-<a name="7" href="#7"><h2>7. Library</h2></a>
+<h2><a name="7" href="#7">7. Library</a></h2>
-<a name="7.1" href="#7.1"><h3>7.1 Introduction</h3></a>
+<h3><a name="7.1" href="#7.1">7.1 Introduction</a></h3>
-<a name="7.1.1" href="#7.1.1"><h4>7.1.1 Definitions of terms</h4></a>
+<h4><a name="7.1.1" href="#7.1.1">7.1.1 Definitions of terms</a></h4>
<p><!--para 1 -->
A string is a contiguous sequence of characters terminated by and including the first null
character. The term multibyte string is sometimes used instead to emphasize special
implementation's choice.
</small>
-<a name="7.1.2" href="#7.1.2"><h4>7.1.2 Standard headers</h4></a>
+<h4><a name="7.1.2" href="#7.1.2">7.1.2 Standard headers</a></h4>
<p><!--para 1 -->
Each library function is declared, with a type that includes a prototype, in a header,<sup><a href="#note182"><b>182)</b></a></sup>
whose contents are made available by the #include preprocessing directive. The
include type qualifiers, unless explicitly stated otherwise.
<p><!--para 2 -->
The standard headers are<sup><a href="#note183"><b>183)</b></a></sup>
-<p><!--para 3 -->
<pre>
<a href="#7.2"><assert.h></a> <a href="#7.9"><iso646.h></a> <a href="#7.16"><stdarg.h></a> <a href="#7.23"><string.h></a>
<a href="#7.3"><complex.h></a> <a href="#7.10"><limits.h></a> <a href="#7.17"><stdatomic.h></a> <a href="#7.24"><tgmath.h></a>
<a href="#7.5"><errno.h></a> <a href="#7.12"><math.h></a> <a href="#7.19"><stddef.h></a> <a href="#7.26"><time.h></a>
<a href="#7.6"><fenv.h></a> <a href="#7.13"><setjmp.h></a> <a href="#7.20"><stdint.h></a> <a href="#7.27"><uchar.h></a>
<a href="#7.7"><float.h></a> <a href="#7.14"><signal.h></a> <a href="#7.21"><stdio.h></a> <a href="#7.28"><wchar.h></a>
- <a href="#7.8"><inttypes.h></a> <a href="#7.15"><stdalign.h></a> <a href="#7.22"><stdlib.h></a> <a href="#7.29"><wctype.h></a></pre>
+ <a href="#7.8"><inttypes.h></a> <a href="#7.15"><stdalign.h></a> <a href="#7.22"><stdlib.h></a> <a href="#7.29"><wctype.h></a>
+</pre>
+<p><!--para 3 -->
If a file with the same name as one of the above < and > delimited sequences, not
provided as part of the implementation, is placed in any of the standard places that are
searched for included source files, the behavior is undefined.
implementations need not support; see <a href="#6.10.8.3">6.10.8.3</a>.
</small>
-<a name="7.1.3" href="#7.1.3"><h4>7.1.3 Reserved identifiers</h4></a>
+<h4><a name="7.1.3" href="#7.1.3">7.1.3 Reserved identifiers</a></h4>
<p><!--para 1 -->
Each header declares or defines all identifiers listed in its associated subclause, and
optionally declares or defines identifiers listed in its associated future library directions
va_copy, and va_end.
</small>
-<a name="7.1.4" href="#7.1.4"><h4>7.1.4 Use of library functions</h4></a>
+<h4><a name="7.1.4" href="#7.1.4">7.1.4 Use of library functions</a></h4>
<p><!--para 1 -->
Each of the following statements applies unless explicitly stated otherwise in the detailed
descriptions that follow: If an argument to a function has an invalid value (such as a value
#include <a href="#7.22"><stdlib.h></a>
const char *str;
/* ... */
- i = atoi(str);</pre>
+ i = atoi(str);
+</pre>
<li> by use of its associated header (assuredly generating a true function reference)
#undef atoi
const char *str;
/* ... */
- i = atoi(str);</pre>
+ i = atoi(str);
+</pre>
or
<pre>
#include <a href="#7.22"><stdlib.h></a>
const char *str;
/* ... */
- i = (atoi)(str);</pre>
+ i = (atoi)(str);
+</pre>
<li> by explicit declaration
<!--page 203 -->
<pre>
extern int atoi(const char *);
const char *str;
/* ... */
- i = atoi(str);</pre>
+ i = atoi(str);
+</pre>
</ul>
<h6>footnotes</h6>
appropriate header could specify
<pre>
- #define abs(x) _BUILTIN_abs(x)</pre>
+ #define abs(x) _BUILTIN_abs(x)
+</pre>
for a compiler whose code generator will accept it.
In this manner, a user desiring to guarantee that a given library function such as abs will be a genuine
function may write
<pre>
- #undef abs</pre>
+ #undef abs
+</pre>
whether the implementation's header provides a macro implementation of abs or a built-in
implementation. The prototype for the function, which precedes and is hidden by any macro
definition, is thereby revealed also.
<p><small><a name="note190" href="#note190">190)</a> This allows implementations to parallelize operations if there are no visible side effects.
</small>
-<a name="7.2" href="#7.2"><h3>7.2 Diagnostics <assert.h></h3></a>
+<h3><a name="7.2" href="#7.2">7.2 Diagnostics <assert.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.2"><assert.h></a> defines the assert and static_assert macros and
refers to another macro,
<pre>
- NDEBUG</pre>
+ NDEBUG
+</pre>
which is not defined by <a href="#7.2"><assert.h></a>. If NDEBUG is defined as a macro name at the
point in the source file where <a href="#7.2"><assert.h></a> is included, the assert macro is defined
simply as
<pre>
- #define assert(ignore) ((void)0)</pre>
+ #define assert(ignore) ((void)0)
+</pre>
The assert macro is redefined according to the current state of NDEBUG each time that
<a href="#7.2"><assert.h></a> is included.
<p><!--para 2 -->
<p><!--para 3 -->
The macro
<pre>
- static_assert</pre>
+ static_assert
+</pre>
expands to _Static_assert.
-<a name="7.2.1" href="#7.2.1"><h4>7.2.1 Program diagnostics</h4></a>
+<h4><a name="7.2.1" href="#7.2.1">7.2.1 Program diagnostics</a></h4>
-<a name="7.2.1.1" href="#7.2.1.1"><h5>7.2.1.1 The assert macro</h5></a>
+<h5><a name="7.2.1.1" href="#7.2.1.1">7.2.1.1 The assert macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.2"><assert.h></a>
- void assert(scalar expression);</pre>
+ void assert(scalar expression);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The assert macro puts diagnostic tests into programs; it expands to a void expression.
Assertion failed: expression, function abc, file xyz, line nnn.
</small>
-<a name="7.3" href="#7.3"><h3>7.3 Complex arithmetic <complex.h></h3></a>
+<h3><a name="7.3" href="#7.3">7.3 Complex arithmetic <complex.h></a></h3>
-<a name="7.3.1" href="#7.3.1"><h4>7.3.1 Introduction</h4></a>
+<h4><a name="7.3.1" href="#7.3.1">7.3.1 Introduction</a></h4>
<p><!--para 1 -->
The header <a href="#7.3"><complex.h></a> defines macros and declares functions that support complex
arithmetic.<sup><a href="#note192"><b>192)</b></a></sup>
<p><!--para 4 -->
The macro
<pre>
- complex</pre>
+ complex
+</pre>
expands to _Complex; the macro
<pre>
- _Complex_I</pre>
+ _Complex_I
+</pre>
expands to a constant expression of type const float _Complex, with the value of
the imaginary unit.<sup><a href="#note193"><b>193)</b></a></sup>
<p><!--para 5 -->
The macros
<pre>
- imaginary</pre>
+ imaginary
+</pre>
and
<pre>
- _Imaginary_I</pre>
+ _Imaginary_I
+</pre>
are defined if and only if the implementation supports imaginary types;<sup><a href="#note194"><b>194)</b></a></sup> if defined,
they expand to _Imaginary and a constant expression of type const float
_Imaginary with the value of the imaginary unit.
<p><!--para 6 -->
The macro
<pre>
- I</pre>
+ I
+</pre>
expands to either _Imaginary_I or _Complex_I. If _Imaginary_I is not
defined, I shall expand to _Complex_I.
<p><!--para 7 -->
<p><small><a name="note194" href="#note194">194)</a> A specification for imaginary types is in informative <a href="#G">annex G</a>.
</small>
-<a name="7.3.2" href="#7.3.2"><h4>7.3.2 Conventions</h4></a>
+<h4><a name="7.3.2" href="#7.3.2">7.3.2 Conventions</a></h4>
<p><!--para 1 -->
Values are interpreted as radians, not degrees. An implementation may set errno but is
not required to.
-<a name="7.3.3" href="#7.3.3"><h4>7.3.3 Branch cuts</h4></a>
+<h4><a name="7.3.3" href="#7.3.3">7.3.3 Branch cuts</a></h4>
<p><!--para 1 -->
Some of the functions below have branch cuts, across which the function is
discontinuous. For implementations with a signed zero (including all IEC 60559
the finite endpoint of the cut along the negative real axis approaches the cut from above,
so the cut maps to the positive imaginary axis.
-<a name="7.3.4" href="#7.3.4"><h4>7.3.4 The CX_LIMITED_RANGE pragma</h4></a>
+<h4><a name="7.3.4" href="#7.3.4">7.3.4 The CX_LIMITED_RANGE pragma</a></h4>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
- #pragma STDC CX_LIMITED_RANGE on-off-switch</pre>
+ #pragma STDC CX_LIMITED_RANGE on-off-switch
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The usual mathematical formulas for complex multiply, divide, and absolute value are
(x + iy) x (u + iv) = (xu - yv) + i(yu + xv)
(x + iy) / (u + iv) = [(xu + yv) + i(yu - xv)]/(u2 + v 2 )
| x + iy | = (sqrt) x 2 + y 2
- -----</pre>
+ -----
+</pre>
where the programmer can determine they are safe.
</small>
-<a name="7.3.5" href="#7.3.5"><h4>7.3.5 Trigonometric functions</h4></a>
+<h4><a name="7.3.5" href="#7.3.5">7.3.5 Trigonometric functions</a></h4>
-<a name="7.3.5.1" href="#7.3.5.1"><h5>7.3.5.1 The cacos functions</h5></a>
+<h5><a name="7.3.5.1" href="#7.3.5.1">7.3.5.1 The cacos functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex cacos(double complex z);
float complex cacosf(float complex z);
- long double complex cacosl(long double complex z);</pre>
+ long double complex cacosl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cacos functions compute the complex arc cosine of z, with branch cuts outside the
mathematically unbounded along the imaginary axis and in the interval [0, pi ] along the
real axis.
-<a name="7.3.5.2" href="#7.3.5.2"><h5>7.3.5.2 The casin functions</h5></a>
+<h5><a name="7.3.5.2" href="#7.3.5.2">7.3.5.2 The casin functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex casin(double complex z);
float complex casinf(float complex z);
- long double complex casinl(long double complex z);</pre>
+ long double complex casinl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The casin functions compute the complex arc sine of z, with branch cuts outside the
<!--page 208 -->
along the real axis.
-<a name="7.3.5.3" href="#7.3.5.3"><h5>7.3.5.3 The catan functions</h5></a>
+<h5><a name="7.3.5.3" href="#7.3.5.3">7.3.5.3 The catan functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex catan(double complex z);
float complex catanf(float complex z);
- long double complex catanl(long double complex z);</pre>
+ long double complex catanl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The catan functions compute the complex arc tangent of z, with branch cuts outside the
mathematically unbounded along the imaginary axis and in the interval [-pi /2, +pi /2]
along the real axis.
-<a name="7.3.5.4" href="#7.3.5.4"><h5>7.3.5.4 The ccos functions</h5></a>
+<h5><a name="7.3.5.4" href="#7.3.5.4">7.3.5.4 The ccos functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex ccos(double complex z);
float complex ccosf(float complex z);
- long double complex ccosl(long double complex z);</pre>
+ long double complex ccosl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ccos functions compute the complex cosine of z.
<p><!--para 3 -->
The ccos functions return the complex cosine value.
-<a name="7.3.5.5" href="#7.3.5.5"><h5>7.3.5.5 The csin functions</h5></a>
+<h5><a name="7.3.5.5" href="#7.3.5.5">7.3.5.5 The csin functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex csin(double complex z);
float complex csinf(float complex z);
- long double complex csinl(long double complex z);</pre>
+ long double complex csinl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The csin functions compute the complex sine of z.
<p><!--para 3 -->
The csin functions return the complex sine value.
-<a name="7.3.5.6" href="#7.3.5.6"><h5>7.3.5.6 The ctan functions</h5></a>
+<h5><a name="7.3.5.6" href="#7.3.5.6">7.3.5.6 The ctan functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex ctan(double complex z);
float complex ctanf(float complex z);
- long double complex ctanl(long double complex z);</pre>
+ long double complex ctanl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ctan functions compute the complex tangent of z.
<p><!--para 3 -->
The ctan functions return the complex tangent value.
-<a name="7.3.6" href="#7.3.6"><h4>7.3.6 Hyperbolic functions</h4></a>
+<h4><a name="7.3.6" href="#7.3.6">7.3.6 Hyperbolic functions</a></h4>
-<a name="7.3.6.1" href="#7.3.6.1"><h5>7.3.6.1 The cacosh functions</h5></a>
+<h5><a name="7.3.6.1" href="#7.3.6.1">7.3.6.1 The cacosh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex cacosh(double complex z);
float complex cacoshf(float complex z);
- long double complex cacoshl(long double complex z);</pre>
+ long double complex cacoshl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cacosh functions compute the complex arc hyperbolic cosine of z, with a branch
half-strip of nonnegative values along the real axis and in the interval [-ipi , +ipi ] along the
imaginary axis.
-<a name="7.3.6.2" href="#7.3.6.2"><h5>7.3.6.2 The casinh functions</h5></a>
+<h5><a name="7.3.6.2" href="#7.3.6.2">7.3.6.2 The casinh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<!--page 210 -->
#include <a href="#7.3"><complex.h></a>
double complex casinh(double complex z);
float complex casinhf(float complex z);
- long double complex casinhl(long double complex z);</pre>
+ long double complex casinhl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The casinh functions compute the complex arc hyperbolic sine of z, with branch cuts
strip mathematically unbounded along the real axis and in the interval [-ipi /2, +ipi /2]
along the imaginary axis.
-<a name="7.3.6.3" href="#7.3.6.3"><h5>7.3.6.3 The catanh functions</h5></a>
+<h5><a name="7.3.6.3" href="#7.3.6.3">7.3.6.3 The catanh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex catanh(double complex z);
float complex catanhf(float complex z);
- long double complex catanhl(long double complex z);</pre>
+ long double complex catanhl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The catanh functions compute the complex arc hyperbolic tangent of z, with branch
strip mathematically unbounded along the real axis and in the interval [-ipi /2, +ipi /2]
along the imaginary axis.
-<a name="7.3.6.4" href="#7.3.6.4"><h5>7.3.6.4 The ccosh functions</h5></a>
+<h5><a name="7.3.6.4" href="#7.3.6.4">7.3.6.4 The ccosh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex ccosh(double complex z);
float complex ccoshf(float complex z);
- long double complex ccoshl(long double complex z);</pre>
+ long double complex ccoshl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ccosh functions compute the complex hyperbolic cosine of z.
The ccosh functions return the complex hyperbolic cosine value.
<!--page 211 -->
-<a name="7.3.6.5" href="#7.3.6.5"><h5>7.3.6.5 The csinh functions</h5></a>
+<h5><a name="7.3.6.5" href="#7.3.6.5">7.3.6.5 The csinh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex csinh(double complex z);
float complex csinhf(float complex z);
- long double complex csinhl(long double complex z);</pre>
+ long double complex csinhl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The csinh functions compute the complex hyperbolic sine of z.
<p><!--para 3 -->
The csinh functions return the complex hyperbolic sine value.
-<a name="7.3.6.6" href="#7.3.6.6"><h5>7.3.6.6 The ctanh functions</h5></a>
+<h5><a name="7.3.6.6" href="#7.3.6.6">7.3.6.6 The ctanh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex ctanh(double complex z);
float complex ctanhf(float complex z);
- long double complex ctanhl(long double complex z);</pre>
+ long double complex ctanhl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ctanh functions compute the complex hyperbolic tangent of z.
<p><!--para 3 -->
The ctanh functions return the complex hyperbolic tangent value.
-<a name="7.3.7" href="#7.3.7"><h4>7.3.7 Exponential and logarithmic functions</h4></a>
+<h4><a name="7.3.7" href="#7.3.7">7.3.7 Exponential and logarithmic functions</a></h4>
-<a name="7.3.7.1" href="#7.3.7.1"><h5>7.3.7.1 The cexp functions</h5></a>
+<h5><a name="7.3.7.1" href="#7.3.7.1">7.3.7.1 The cexp functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex cexp(double complex z);
float complex cexpf(float complex z);
- long double complex cexpl(long double complex z);</pre>
+ long double complex cexpl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cexp functions compute the complex base-e exponential of z.
The cexp functions return the complex base-e exponential value.
<!--page 212 -->
-<a name="7.3.7.2" href="#7.3.7.2"><h5>7.3.7.2 The clog functions</h5></a>
+<h5><a name="7.3.7.2" href="#7.3.7.2">7.3.7.2 The clog functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex clog(double complex z);
float complex clogf(float complex z);
- long double complex clogl(long double complex z);</pre>
+ long double complex clogl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The clog functions compute the complex natural (base-e) logarithm of z, with a branch
mathematically unbounded along the real axis and in the interval [-ipi , +ipi ] along the
imaginary axis.
-<a name="7.3.8" href="#7.3.8"><h4>7.3.8 Power and absolute-value functions</h4></a>
+<h4><a name="7.3.8" href="#7.3.8">7.3.8 Power and absolute-value functions</a></h4>
-<a name="7.3.8.1" href="#7.3.8.1"><h5>7.3.8.1 The cabs functions</h5></a>
+<h5><a name="7.3.8.1" href="#7.3.8.1">7.3.8.1 The cabs functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double cabs(double complex z);
float cabsf(float complex z);
- long double cabsl(long double complex z);</pre>
+ long double cabsl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cabs functions compute the complex absolute value (also called norm, modulus, or
<p><!--para 3 -->
The cabs functions return the complex absolute value.
-<a name="7.3.8.2" href="#7.3.8.2"><h5>7.3.8.2 The cpow functions</h5></a>
+<h5><a name="7.3.8.2" href="#7.3.8.2">7.3.8.2 The cpow functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<!--page 213 -->
double complex cpow(double complex x, double complex y);
float complex cpowf(float complex x, float complex y);
long double complex cpowl(long double complex x,
- long double complex y);</pre>
+ long double complex y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cpow functions compute the complex power function xy , with a branch cut for the
<p><!--para 3 -->
The cpow functions return the complex power function value.
-<a name="7.3.8.3" href="#7.3.8.3"><h5>7.3.8.3 The csqrt functions</h5></a>
+<h5><a name="7.3.8.3" href="#7.3.8.3">7.3.8.3 The csqrt functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex csqrt(double complex z);
float complex csqrtf(float complex z);
- long double complex csqrtl(long double complex z);</pre>
+ long double complex csqrtl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The csqrt functions compute the complex square root of z, with a branch cut along the
The csqrt functions return the complex square root value, in the range of the right half-
plane (including the imaginary axis).
-<a name="7.3.9" href="#7.3.9"><h4>7.3.9 Manipulation functions</h4></a>
+<h4><a name="7.3.9" href="#7.3.9">7.3.9 Manipulation functions</a></h4>
-<a name="7.3.9.1" href="#7.3.9.1"><h5>7.3.9.1 The carg functions</h5></a>
+<h5><a name="7.3.9.1" href="#7.3.9.1">7.3.9.1 The carg functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double carg(double complex z);
float cargf(float complex z);
- long double cargl(long double complex z);</pre>
+ long double cargl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The carg functions compute the argument (also called phase angle) of z, with a branch
The carg functions return the value of the argument in the interval [-pi , +pi ].
<!--page 214 -->
-<a name="7.3.9.2" href="#7.3.9.2"><h5>7.3.9.2 The cimag functions</h5></a>
+<h5><a name="7.3.9.2" href="#7.3.9.2">7.3.9.2 The cimag functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double cimag(double complex z);
float cimagf(float complex z);
- long double cimagl(long double complex z);</pre>
+ long double cimagl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cimag functions compute the imaginary part of z.<sup><a href="#note196"><b>196)</b></a></sup>
<p><small><a name="note196" href="#note196">196)</a> For a variable z of complex type, z == creal(z) + cimag(z)*I.
</small>
-<a name="7.3.9.3" href="#7.3.9.3"><h5>7.3.9.3 The CMPLX macros</h5></a>
+<h5><a name="7.3.9.3" href="#7.3.9.3">7.3.9.3 The CMPLX macros</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex CMPLX(double x, double y);
float complex CMPLXF(float x, float y);
- long double complex CMPLXL(long double x, long double y);</pre>
+ long double complex CMPLXL(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The CMPLX macros expand to an expression of the specified complex type, with the real
part having the (converted) value of x and the imaginary part having the (converted)
value of y.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 3 -->
The resulting expression should be suitable for use as an initializer for an object with
static or thread storage duration, provided both arguments are likewise suitable.
#define CMPLXF(x, y) ((float complex)((float)(x) + \
_Imaginary_I * (float)(y)))
#define CMPLXL(x, y) ((long double complex)((long double)(x) + \
- _Imaginary_I * (long double)(y)))</pre>
+ _Imaginary_I * (long double)(y)))
+</pre>
<!--page 215 -->
-<a name="7.3.9.4" href="#7.3.9.4"><h5>7.3.9.4 The conj functions</h5></a>
+<h5><a name="7.3.9.4" href="#7.3.9.4">7.3.9.4 The conj functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex conj(double complex z);
float complex conjf(float complex z);
- long double complex conjl(long double complex z);</pre>
+ long double complex conjl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The conj functions compute the complex conjugate of z, by reversing the sign of its
<p><!--para 3 -->
The conj functions return the complex conjugate value.
-<a name="7.3.9.5" href="#7.3.9.5"><h5>7.3.9.5 The cproj functions</h5></a>
+<h5><a name="7.3.9.5" href="#7.3.9.5">7.3.9.5 The cproj functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double complex cproj(double complex z);
float complex cprojf(float complex z);
- long double complex cprojl(long double complex z);</pre>
+ long double complex cprojl(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cproj functions compute a projection of z onto the Riemann sphere: z projects to
project to positive infinity on the real axis. If z has an infinite part, then cproj(z) is
equivalent to
<pre>
- INFINITY + I * copysign(0.0, cimag(z))</pre>
+ INFINITY + I * copysign(0.0, cimag(z))
+</pre>
<h6>Returns</h6>
<p><!--para 3 -->
The cproj functions return the value of the projection onto the Riemann sphere.
-<a name="7.3.9.6" href="#7.3.9.6"><h5>7.3.9.6 The creal functions</h5></a>
+<h5><a name="7.3.9.6" href="#7.3.9.6">7.3.9.6 The creal functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.3"><complex.h></a>
double creal(double complex z);
float crealf(float complex z);
- long double creall(long double complex z);</pre>
+ long double creall(long double complex z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The creal functions compute the real part of z.<sup><a href="#note197"><b>197)</b></a></sup>
<p><small><a name="note197" href="#note197">197)</a> For a variable z of complex type, z == creal(z) + cimag(z)*I.
</small>
-<a name="7.4" href="#7.4"><h3>7.4 Character handling <ctype.h></h3></a>
+<h3><a name="7.4" href="#7.4">7.4 Character handling <ctype.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.4"><ctype.h></a> declares several functions useful for classifying and mapping
characters.<sup><a href="#note198"><b>198)</b></a></sup> In all cases the argument is an int, the value of which shall be
values lie from 0 (NUL) through 0x1F (US), and the character 0x7F (DEL).
</small>
-<a name="7.4.1" href="#7.4.1"><h4>7.4.1 Character classification functions</h4></a>
+<h4><a name="7.4.1" href="#7.4.1">7.4.1 Character classification functions</a></h4>
<p><!--para 1 -->
The functions in this subclause return nonzero (true) if and only if the value of the
argument c conforms to that in the description of the function.
-<a name="7.4.1.1" href="#7.4.1.1"><h5>7.4.1.1 The isalnum function</h5></a>
+<h5><a name="7.4.1.1" href="#7.4.1.1">7.4.1.1 The isalnum function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isalnum(int c);</pre>
+ int isalnum(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isalnum function tests for any character for which isalpha or isdigit is true.
-<a name="7.4.1.2" href="#7.4.1.2"><h5>7.4.1.2 The isalpha function</h5></a>
+<h5><a name="7.4.1.2" href="#7.4.1.2">7.4.1.2 The isalpha function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isalpha(int c);</pre>
+ int isalpha(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isalpha function tests for any character for which isupper or islower is true,
characters; all four combinations are possible.
</small>
-<a name="7.4.1.3" href="#7.4.1.3"><h5>7.4.1.3 The isblank function</h5></a>
+<h5><a name="7.4.1.3" href="#7.4.1.3">7.4.1.3 The isblank function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isblank(int c);</pre>
+ int isblank(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isblank function tests for any character that is a standard blank character or is one
space (' '), and horizontal tab ('\t'). In the "C" locale, isblank returns true only
for the standard blank characters.
-<a name="7.4.1.4" href="#7.4.1.4"><h5>7.4.1.4 The iscntrl function</h5></a>
+<h5><a name="7.4.1.4" href="#7.4.1.4">7.4.1.4 The iscntrl function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int iscntrl(int c);</pre>
+ int iscntrl(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iscntrl function tests for any control character.
-<a name="7.4.1.5" href="#7.4.1.5"><h5>7.4.1.5 The isdigit function</h5></a>
+<h5><a name="7.4.1.5" href="#7.4.1.5">7.4.1.5 The isdigit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isdigit(int c);</pre>
+ int isdigit(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isdigit function tests for any decimal-digit character (as defined in <a href="#5.2.1">5.2.1</a>).
-<a name="7.4.1.6" href="#7.4.1.6"><h5>7.4.1.6 The isgraph function</h5></a>
+<h5><a name="7.4.1.6" href="#7.4.1.6">7.4.1.6 The isgraph function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isgraph(int c);</pre>
+ int isgraph(int c);
+</pre>
<p><!--para 2 -->
The isgraph function tests for any printing character except space (' ').
-<a name="7.4.1.7" href="#7.4.1.7"><h5>7.4.1.7 The islower function</h5></a>
+<h5><a name="7.4.1.7" href="#7.4.1.7">7.4.1.7 The islower function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int islower(int c);</pre>
+ int islower(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The islower function tests for any character that is a lowercase letter or is one of a
isspace is true. In the "C" locale, islower returns true only for the lowercase
letters (as defined in <a href="#5.2.1">5.2.1</a>).
-<a name="7.4.1.8" href="#7.4.1.8"><h5>7.4.1.8 The isprint function</h5></a>
+<h5><a name="7.4.1.8" href="#7.4.1.8">7.4.1.8 The isprint function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isprint(int c);</pre>
+ int isprint(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isprint function tests for any printing character including space (' ').
-<a name="7.4.1.9" href="#7.4.1.9"><h5>7.4.1.9 The ispunct function</h5></a>
+<h5><a name="7.4.1.9" href="#7.4.1.9">7.4.1.9 The ispunct function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int ispunct(int c);</pre>
+ int ispunct(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ispunct function tests for any printing character that is one of a locale-specific set
locale, ispunct returns true for every printing character for which neither isspace
nor isalnum is true.
-<a name="7.4.1.10" href="#7.4.1.10"><h5>7.4.1.10 The isspace function</h5></a>
+<h5><a name="7.4.1.10" href="#7.4.1.10">7.4.1.10 The isspace function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isspace(int c);</pre>
+ int isspace(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isspace function tests for any character that is a standard white-space character or
('\n'), carriage return ('\r'), horizontal tab ('\t'), and vertical tab ('\v'). In the
"C" locale, isspace returns true only for the standard white-space characters.
-<a name="7.4.1.11" href="#7.4.1.11"><h5>7.4.1.11 The isupper function</h5></a>
+<h5><a name="7.4.1.11" href="#7.4.1.11">7.4.1.11 The isupper function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isupper(int c);</pre>
+ int isupper(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isupper function tests for any character that is an uppercase letter or is one of a
isspace is true. In the "C" locale, isupper returns true only for the uppercase
letters (as defined in <a href="#5.2.1">5.2.1</a>).
-<a name="7.4.1.12" href="#7.4.1.12"><h5>7.4.1.12 The isxdigit function</h5></a>
+<h5><a name="7.4.1.12" href="#7.4.1.12">7.4.1.12 The isxdigit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int isxdigit(int c);</pre>
+ int isxdigit(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isxdigit function tests for any hexadecimal-digit character (as defined in <a href="#6.4.4.1">6.4.4.1</a>).
-<a name="7.4.2" href="#7.4.2"><h4>7.4.2 Character case mapping functions</h4></a>
+<h4><a name="7.4.2" href="#7.4.2">7.4.2 Character case mapping functions</a></h4>
-<a name="7.4.2.1" href="#7.4.2.1"><h5>7.4.2.1 The tolower function</h5></a>
+<h5><a name="7.4.2.1" href="#7.4.2.1">7.4.2.1 The tolower function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int tolower(int c);</pre>
+ int tolower(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tolower function converts an uppercase letter to a corresponding lowercase letter.
for any given locale); otherwise, the argument is returned unchanged.
<!--page 221 -->
-<a name="7.4.2.2" href="#7.4.2.2"><h5>7.4.2.2 The toupper function</h5></a>
+<h5><a name="7.4.2.2" href="#7.4.2.2">7.4.2.2 The toupper function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.4"><ctype.h></a>
- int toupper(int c);</pre>
+ int toupper(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The toupper function converts a lowercase letter to a corresponding uppercase letter.
for any given locale); otherwise, the argument is returned unchanged.
<!--page 222 -->
-<a name="7.5" href="#7.5"><h3>7.5 Errors <errno.h></h3></a>
+<h3><a name="7.5" href="#7.5">7.5 Errors <errno.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.5"><errno.h></a> defines several macros, all relating to the reporting of error
conditions.
<pre>
EDOM
EILSEQ
- ERANGE</pre>
+ ERANGE
+</pre>
which expand to integer constant expressions with type int, distinct positive values, and
which are suitable for use in #if preprocessing directives; and
<pre>
- errno</pre>
+ errno
+</pre>
which expands to a modifiable lvalue<sup><a href="#note201"><b>201)</b></a></sup> that has type int and thread local storage
duration, the value of which is set to a positive error number by several library functions.
If a macro definition is suppressed in order to access an actual object, or a program
<p><small><a name="note203" href="#note203">203)</a> See ''future library directions'' (<a href="#7.30.3">7.30.3</a>).
</small>
-<a name="7.6" href="#7.6"><h3>7.6 Floating-point environment <fenv.h></h3></a>
+<h3><a name="7.6" href="#7.6">7.6 Floating-point environment <fenv.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.6"><fenv.h></a> defines several macros, and declares types and functions that
provide access to the floating-point environment. The floating-point environment refers
<p><!--para 4 -->
The type
<pre>
- fenv_t</pre>
+ fenv_t
+</pre>
represents the entire floating-point environment.
<p><!--para 5 -->
The type
<pre>
- fexcept_t</pre>
+ fexcept_t
+</pre>
represents the floating-point status flags collectively, including any status the
implementation associates with the flags.
FE_INEXACT
FE_INVALID
FE_OVERFLOW
- FE_UNDERFLOW</pre>
+ FE_UNDERFLOW
+</pre>
is defined if and only if the implementation supports the floating-point exception by
means of the functions in 7.6.2.<sup><a href="#note207"><b>207)</b></a></sup> Additional implementation-defined floating-point
exceptions, with macro definitions beginning with FE_ and an uppercase letter, may also
<p><!--para 7 -->
The macro
<pre>
- FE_ALL_EXCEPT</pre>
+ FE_ALL_EXCEPT
+</pre>
is simply the bitwise OR of all floating-point exception macros defined by the
implementation. If no such macros are defined, FE_ALL_EXCEPT shall be defined as 0.
<p><!--para 8 -->
FE_DOWNWARD
FE_TONEAREST
FE_TOWARDZERO
- FE_UPWARD</pre>
+ FE_UPWARD
+</pre>
is defined if and only if the implementation supports getting and setting the represented
rounding direction by means of the fegetround and fesetround functions.
Additional implementation-defined rounding directions, with macro definitions beginning
<!--page 225 -->
<pre>
- FE_DFL_ENV</pre>
+ FE_DFL_ENV
+</pre>
represents the default floating-point environment -- the one installed at program startup
<ul>
<li> and has type ''pointer to const-qualified fenv_t''. It can be used as an argument to
FLT_ROUNDS, they are not required to do so.
</small>
-<a name="7.6.1" href="#7.6.1"><h4>7.6.1 The FENV_ACCESS pragma</h4></a>
+<h4><a name="7.6.1" href="#7.6.1">7.6.1 The FENV_ACCESS pragma</a></h4>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- #pragma STDC FENV_ACCESS on-off-switch</pre>
+ #pragma STDC FENV_ACCESS on-off-switch
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The FENV_ACCESS pragma provides a means to inform the implementation when a
<!--page 226 -->
<p><!--para 3 -->
EXAMPLE
-<p><!--para 4 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
void f(double x)
g(x + 1);
h(x + 1);
/* ... */
- }</pre>
+ }
+</pre>
+<p><!--para 4 -->
If the function g might depend on status flags set as a side effect of the first x + 1, or if the second
x + 1 might depend on control modes set as a side effect of the call to function g, then the program shall
contain an appropriately placed invocation of #pragma STDC FENV_ACCESS ON.<sup><a href="#note211"><b>211)</b></a></sup>
''off'', just one evaluation of x + 1 would suffice.
</small>
-<a name="7.6.2" href="#7.6.2"><h4>7.6.2 Floating-point exceptions</h4></a>
+<h4><a name="7.6.2" href="#7.6.2">7.6.2 Floating-point exceptions</a></h4>
<p><!--para 1 -->
The following functions provide access to the floating-point status flags.<sup><a href="#note212"><b>212)</b></a></sup> The int
input argument for the functions represents a subset of floating-point exceptions, and can
content of flags.
</small>
-<a name="7.6.2.1" href="#7.6.2.1"><h5>7.6.2.1 The feclearexcept function</h5></a>
+<h5><a name="7.6.2.1" href="#7.6.2.1">7.6.2.1 The feclearexcept function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int feclearexcept(int excepts);</pre>
+ int feclearexcept(int excepts);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The feclearexcept function attempts to clear the supported floating-point exceptions
<!--page 227 -->
-<a name="7.6.2.2" href="#7.6.2.2"><h5>7.6.2.2 The fegetexceptflag function</h5></a>
+<h5><a name="7.6.2.2" href="#7.6.2.2">7.6.2.2 The fegetexceptflag function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
int fegetexceptflag(fexcept_t *flagp,
- int excepts);</pre>
+ int excepts);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fegetexceptflag function attempts to store an implementation-defined
The fegetexceptflag function returns zero if the representation was successfully
stored. Otherwise, it returns a nonzero value.
-<a name="7.6.2.3" href="#7.6.2.3"><h5>7.6.2.3 The feraiseexcept function</h5></a>
+<h5><a name="7.6.2.3" href="#7.6.2.3">7.6.2.3 The feraiseexcept function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int feraiseexcept(int excepts);</pre>
+ int feraiseexcept(int excepts);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The feraiseexcept function attempts to raise the supported floating-point exceptions
in <a href="#F.8.6">F.8.6</a> is in the same spirit.
</small>
-<a name="7.6.2.4" href="#7.6.2.4"><h5>7.6.2.4 The fesetexceptflag function</h5></a>
+<h5><a name="7.6.2.4" href="#7.6.2.4">7.6.2.4 The fesetexceptflag function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
int fesetexceptflag(const fexcept_t *flagp,
- int excepts);</pre>
+ int excepts);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fesetexceptflag function attempts to set the floating-point status flags
all the specified flags were successfully set to the appropriate state. Otherwise, it returns
a nonzero value.
-<a name="7.6.2.5" href="#7.6.2.5"><h5>7.6.2.5 The fetestexcept function</h5></a>
+<h5><a name="7.6.2.5" href="#7.6.2.5">7.6.2.5 The fetestexcept function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int fetestexcept(int excepts);</pre>
+ int fetestexcept(int excepts);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fetestexcept function determines which of a specified subset of the floating-
if (set_excepts & FE_INVALID) f();
if (set_excepts & FE_OVERFLOW) g();
/* ... */
- }</pre>
+ }
+</pre>
<h6>footnotes</h6>
<p><small><a name="note214" href="#note214">214)</a> This mechanism allows testing several floating-point exceptions with just one function call.
</small>
-<a name="7.6.3" href="#7.6.3"><h4>7.6.3 Rounding</h4></a>
+<h4><a name="7.6.3" href="#7.6.3">7.6.3 Rounding</a></h4>
<p><!--para 1 -->
The fegetround and fesetround functions provide control of rounding direction
modes.
-<a name="7.6.3.1" href="#7.6.3.1"><h5>7.6.3.1 The fegetround function</h5></a>
+<h5><a name="7.6.3.1" href="#7.6.3.1">7.6.3.1 The fegetround function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int fegetround(void);</pre>
+ int fegetround(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fegetround function gets the current rounding direction.
representing the current rounding direction or a negative value if there is no such
rounding direction macro or the current rounding direction is not determinable.
-<a name="7.6.3.2" href="#7.6.3.2"><h5>7.6.3.2 The fesetround function</h5></a>
+<h5><a name="7.6.3.2" href="#7.6.3.2">7.6.3.2 The fesetround function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int fesetround(int round);</pre>
+ int fesetround(int round);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fesetround function establishes the rounding direction represented by its
/* ... */
fesetround(save_round);
/* ... */
- }</pre>
+ }
+</pre>
-<a name="7.6.4" href="#7.6.4"><h4>7.6.4 Environment</h4></a>
+<h4><a name="7.6.4" href="#7.6.4">7.6.4 Environment</a></h4>
<p><!--para 1 -->
The functions in this section manage the floating-point environment -- status flags and
control modes -- as one entity.
-<a name="7.6.4.1" href="#7.6.4.1"><h5>7.6.4.1 The fegetenv function</h5></a>
+<h5><a name="7.6.4.1" href="#7.6.4.1">7.6.4.1 The fegetenv function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int fegetenv(fenv_t *envp);</pre>
+ int fegetenv(fenv_t *envp);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fegetenv function attempts to store the current floating-point environment in the
The fegetenv function returns zero if the environment was successfully stored.
Otherwise, it returns a nonzero value.
-<a name="7.6.4.2" href="#7.6.4.2"><h5>7.6.4.2 The feholdexcept function</h5></a>
+<h5><a name="7.6.4.2" href="#7.6.4.2">7.6.4.2 The feholdexcept function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int feholdexcept(fenv_t *envp);</pre>
+ int feholdexcept(fenv_t *envp);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The feholdexcept function saves the current floating-point environment in the object
function to write routines that hide spurious floating-point exceptions from their callers.
</small>
-<a name="7.6.4.3" href="#7.6.4.3"><h5>7.6.4.3 The fesetenv function</h5></a>
+<h5><a name="7.6.4.3" href="#7.6.4.3">7.6.4.3 The fesetenv function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int fesetenv(const fenv_t *envp);</pre>
+ int fesetenv(const fenv_t *envp);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fesetenv function attempts to establish the floating-point environment represented
The fesetenv function returns zero if the environment was successfully established.
Otherwise, it returns a nonzero value.
-<a name="7.6.4.4" href="#7.6.4.4"><h5>7.6.4.4 The feupdateenv function</h5></a>
+<h5><a name="7.6.4.4" href="#7.6.4.4">7.6.4.4 The feupdateenv function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
- int feupdateenv(const fenv_t *envp);</pre>
+ int feupdateenv(const fenv_t *envp);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The feupdateenv function attempts to save the currently raised floating-point
if (feupdateenv(&save_env))
return /* indication of an environmental problem */;
return result;
- }</pre>
+ }
+</pre>
-<a name="7.7" href="#7.7"><h3>7.7 Characteristics of floating types <float.h></h3></a>
+<h3><a name="7.7" href="#7.7">7.7 Characteristics of floating types <float.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.7"><float.h></a> defines several macros that expand to various limits and
parameters of the standard floating-point types.
in <a href="#5.2.4.2.2">5.2.4.2.2</a>.
<!--page 234 -->
-<a name="7.8" href="#7.8"><h3>7.8 Format conversion of integer types <inttypes.h></h3></a>
+<h3><a name="7.8" href="#7.8">7.8 Format conversion of integer types <inttypes.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.8"><inttypes.h></a> includes the header <a href="#7.20"><stdint.h></a> and extends it with
additional facilities provided by hosted implementations.
It declares functions for manipulating greatest-width integers and converting numeric
character strings to greatest-width integers, and it declares the type
<pre>
- imaxdiv_t</pre>
+ imaxdiv_t
+</pre>
which is a structure type that is the type of the value returned by the imaxdiv function.
For each type declared in <a href="#7.20"><stdint.h></a>, it defines corresponding macros for conversion
specifiers for use with the formatted input/output functions.<sup><a href="#note216"><b>216)</b></a></sup>
<p><small><a name="note216" href="#note216">216)</a> See ''future library directions'' (<a href="#7.30.4">7.30.4</a>).
</small>
-<a name="7.8.1" href="#7.8.1"><h4>7.8.1 Macros for format specifiers</h4></a>
+<h4><a name="7.8.1" href="#7.8.1">7.8.1 Macros for format specifiers</a></h4>
<p><!--para 1 -->
Each of the following object-like macros expands to a character string literal containing a *
conversion specifier, possibly modified by a length modifier, suitable for use within the
format string to print the value of an integer of type int_fast32_t.
<p><!--para 2 -->
The fprintf macros for signed integers are:
-<p><!--para 3 -->
<pre>
PRIdN PRIdLEASTN PRIdFASTN PRIdMAX PRIdPTR
- PRIiN PRIiLEASTN PRIiFASTN PRIiMAX PRIiPTR</pre>
+ PRIiN PRIiLEASTN PRIiFASTN PRIiMAX PRIiPTR
+</pre>
+<p><!--para 3 -->
The fprintf macros for unsigned integers are:
-<p><!--para 4 -->
<pre>
PRIoN PRIoLEASTN PRIoFASTN PRIoMAX PRIoPTR
PRIuN PRIuLEASTN PRIuFASTN PRIuMAX PRIuPTR
PRIxN PRIxLEASTN PRIxFASTN PRIxMAX PRIxPTR
- PRIXN PRIXLEASTN PRIXFASTN PRIXMAX PRIXPTR</pre>
+ PRIXN PRIXLEASTN PRIXFASTN PRIXMAX PRIXPTR
+</pre>
+<p><!--para 4 -->
The fscanf macros for signed integers are:
<!--page 235 -->
-<p><!--para 5 -->
<pre>
SCNdN SCNdLEASTN SCNdFASTN SCNdMAX SCNdPTR
- SCNiN SCNiLEASTN SCNiFASTN SCNiMAX SCNiPTR</pre>
+ SCNiN SCNiLEASTN SCNiFASTN SCNiMAX SCNiPTR
+</pre>
+<p><!--para 5 -->
The fscanf macros for unsigned integers are:
-<p><!--para 6 -->
<pre>
SCNoN SCNoLEASTN SCNoFASTN SCNoMAX SCNoPTR
SCNuN SCNuLEASTN SCNuFASTN SCNuMAX SCNuPTR
- SCNxN SCNxLEASTN SCNxFASTN SCNxMAX SCNxPTR</pre>
+ SCNxN SCNxLEASTN SCNxFASTN SCNxMAX SCNxPTR
+</pre>
+<p><!--para 6 -->
For each type that the implementation provides in <a href="#7.20"><stdint.h></a>, the corresponding
fprintf macros shall be defined and the corresponding fscanf macros shall be
defined unless the implementation does not have a suitable fscanf length modifier for
wprintf(L"The largest integer value is %020"
PRIxMAX "\n", i);
return 0;
- }</pre>
+ }
+</pre>
<h6>footnotes</h6>
same.
</small>
-<a name="7.8.2" href="#7.8.2"><h4>7.8.2 Functions for greatest-width integer types</h4></a>
+<h4><a name="7.8.2" href="#7.8.2">7.8.2 Functions for greatest-width integer types</a></h4>
-<a name="7.8.2.1" href="#7.8.2.1"><h5>7.8.2.1 The imaxabs function</h5></a>
+<h5><a name="7.8.2.1" href="#7.8.2.1">7.8.2.1 The imaxabs function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.8"><inttypes.h></a>
- intmax_t imaxabs(intmax_t j);</pre>
+ intmax_t imaxabs(intmax_t j);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The imaxabs function computes the absolute value of an integer j. If the result cannot
<p><small><a name="note218" href="#note218">218)</a> The absolute value of the most negative number cannot be represented in two's complement.
</small>
-<a name="7.8.2.2" href="#7.8.2.2"><h5>7.8.2.2 The imaxdiv function</h5></a>
+<h5><a name="7.8.2.2" href="#7.8.2.2">7.8.2.2 The imaxdiv function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.8"><inttypes.h></a>
- imaxdiv_t imaxdiv(intmax_t numer, intmax_t denom);</pre>
+ imaxdiv_t imaxdiv(intmax_t numer, intmax_t denom);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The imaxdiv function computes numer / denom and numer % denom in a single
quot (the quotient) and rem (the remainder), each of which has type intmax_t. If
either part of the result cannot be represented, the behavior is undefined.
-<a name="7.8.2.3" href="#7.8.2.3"><h5>7.8.2.3 The strtoimax and strtoumax functions</h5></a>
+<h5><a name="7.8.2.3" href="#7.8.2.3">7.8.2.3 The strtoimax and strtoumax functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
intmax_t strtoimax(const char * restrict nptr,
char ** restrict endptr, int base);
uintmax_t strtoumax(const char * restrict nptr,
- char ** restrict endptr, int base);</pre>
+ char ** restrict endptr, int base);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strtoimax and strtoumax functions are equivalent to the strtol, strtoll,
(<a href="#7.22.1.4">7.22.1.4</a>).
<!--page 237 -->
-<a name="7.8.2.4" href="#7.8.2.4"><h5>7.8.2.4 The wcstoimax and wcstoumax functions</h5></a>
+<h5><a name="7.8.2.4" href="#7.8.2.4">7.8.2.4 The wcstoimax and wcstoumax functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
intmax_t wcstoimax(const wchar_t * restrict nptr,
wchar_t ** restrict endptr, int base);
uintmax_t wcstoumax(const wchar_t * restrict nptr,
- wchar_t ** restrict endptr, int base);</pre>
+ wchar_t ** restrict endptr, int base);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcstoimax and wcstoumax functions are equivalent to the wcstol, wcstoll,
(<a href="#7.28.4.1.2">7.28.4.1.2</a>).
<!--page 238 -->
-<a name="7.9" href="#7.9"><h3>7.9 Alternative spellings <iso646.h></h3></a>
+<h3><a name="7.9" href="#7.9">7.9 Alternative spellings <iso646.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.9"><iso646.h></a> defines the following eleven macros (on the left) that expand
to the corresponding tokens (on the right):
or ||
or_eq |=
xor ^
- xor_eq ^=</pre>
+ xor_eq ^=
+</pre>
-<a name="7.10" href="#7.10"><h3>7.10 Sizes of integer types <limits.h></h3></a>
+<h3><a name="7.10" href="#7.10">7.10 Sizes of integer types <limits.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.10"><limits.h></a> defines several macros that expand to various limits and
parameters of the standard integer types.
in <a href="#5.2.4.2.1">5.2.4.2.1</a>.
<!--page 240 -->
-<a name="7.11" href="#7.11"><h3>7.11 Localization <locale.h></h3></a>
+<h3><a name="7.11" href="#7.11">7.11 Localization <locale.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.11"><locale.h></a> declares two functions, one type, and defines several macros.
<p><!--para 2 -->
The type is
<pre>
- struct lconv</pre>
+ struct lconv
+</pre>
which contains members related to the formatting of numeric values. The structure shall
contain at least the following members, in any order. The semantics of the members and
their normal ranges are explained in <a href="#7.11.2.1">7.11.2.1</a>. In the "C" locale, the members shall have
the values specified in the comments.
<!--page 241 -->
-<p><!--para 3 -->
<pre>
char *decimal_point; // "."
char *thousands_sep; // ""
char int_p_sep_by_space; // CHAR_MAX
char int_n_sep_by_space; // CHAR_MAX
char int_p_sign_posn; // CHAR_MAX
- char int_n_sign_posn; // CHAR_MAX</pre>
+ char int_n_sign_posn; // CHAR_MAX
+</pre>
+<p><!--para 3 -->
The macros defined are NULL (described in <a href="#7.19">7.19</a>); and
<pre>
LC_ALL
LC_CTYPE
LC_MONETARY
LC_NUMERIC
- LC_TIME</pre>
+ LC_TIME
+</pre>
which expand to integer constant expressions with distinct values, suitable for use as the
first argument to the setlocale function.<sup><a href="#note219"><b>219)</b></a></sup> Additional macro definitions, beginning
with the characters LC_ and an uppercase letter,<sup><a href="#note220"><b>220)</b></a></sup> may also be specified by the
<p><small><a name="note220" href="#note220">220)</a> See ''future library directions'' (<a href="#7.30.5">7.30.5</a>).
</small>
-<a name="7.11.1" href="#7.11.1"><h4>7.11.1 Locale control</h4></a>
+<h4><a name="7.11.1" href="#7.11.1">7.11.1 Locale control</a></h4>
-<a name="7.11.1.1" href="#7.11.1.1"><h5>7.11.1.1 The setlocale function</h5></a>
+<h5><a name="7.11.1.1" href="#7.11.1.1">7.11.1.1 The setlocale function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.11"><locale.h></a>
- char *setlocale(int category, const char *locale);</pre>
+ char *setlocale(int category, const char *locale);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The setlocale function selects the appropriate portion of the program's locale as
<p><!--para 4 -->
At program startup, the equivalent of
<pre>
- setlocale(LC_ALL, "C");</pre>
+ setlocale(LC_ALL, "C");
+</pre>
is executed.
<p><!--para 5 -->
A call to the setlocale function may introduce a data race with other calls to the
locale when category has the value LC_ALL.
</small>
-<a name="7.11.2" href="#7.11.2"><h4>7.11.2 Numeric formatting convention inquiry</h4></a>
+<h4><a name="7.11.2" href="#7.11.2">7.11.2 Numeric formatting convention inquiry</a></h4>
-<a name="7.11.2.1" href="#7.11.2.1"><h5>7.11.2.1 The localeconv function</h5></a>
+<h5><a name="7.11.2.1" href="#7.11.2.1">7.11.2.1 The localeconv function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.11"><locale.h></a>
- struct lconv *localeconv(void);</pre>
+ struct lconv *localeconv(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The localeconv function sets the components of an object with type struct lconv
available in the current locale. The members include the following:
char *decimal_point
<pre>
- The decimal-point character used to format nonmonetary quantities.</pre>
+ The decimal-point character used to format nonmonetary quantities.
+</pre>
char *thousands_sep
<pre>
The character used to separate groups of digits before the decimal-point
- character in formatted nonmonetary quantities.</pre>
+ character in formatted nonmonetary quantities.
+</pre>
char *grouping
<pre>
A string whose elements indicate the size of each group of digits in
- formatted nonmonetary quantities.</pre>
+ formatted nonmonetary quantities.
+</pre>
char *mon_decimal_point
<pre>
- The decimal-point used to format monetary quantities.</pre>
+ The decimal-point used to format monetary quantities.
+</pre>
char *mon_thousands_sep
<pre>
The separator for groups of digits before the decimal-point in formatted
- monetary quantities.</pre>
+ monetary quantities.
+</pre>
char *mon_grouping
<pre>
A string whose elements indicate the size of each group of digits in
- formatted monetary quantities.</pre>
+ formatted monetary quantities.
+</pre>
char *positive_sign
<pre>
The string used to indicate a nonnegative-valued formatted monetary
- quantity.</pre>
+ quantity.
+</pre>
char *negative_sign
<pre>
- The string used to indicate a negative-valued formatted monetary quantity.</pre>
+ The string used to indicate a negative-valued formatted monetary quantity.
+</pre>
char *currency_symbol
<pre>
- The local currency symbol applicable to the current locale.</pre>
+ The local currency symbol applicable to the current locale.
+</pre>
char frac_digits
<pre>
The number of fractional digits (those after the decimal-point) to be
- displayed in a locally formatted monetary quantity.</pre>
+ displayed in a locally formatted monetary quantity.
+</pre>
char p_cs_precedes
<!--page 244 -->
<pre>
Set to 1 or 0 if the currency_symbol respectively precedes or
- succeeds the value for a nonnegative locally formatted monetary quantity.</pre>
+ succeeds the value for a nonnegative locally formatted monetary quantity.
+</pre>
char n_cs_precedes
<pre>
Set to 1 or 0 if the currency_symbol respectively precedes or
- succeeds the value for a negative locally formatted monetary quantity.</pre>
+ succeeds the value for a negative locally formatted monetary quantity.
+</pre>
char p_sep_by_space
<pre>
Set to a value indicating the separation of the currency_symbol, the
sign string, and the value for a nonnegative locally formatted monetary
- quantity.</pre>
+ quantity.
+</pre>
char n_sep_by_space
<pre>
Set to a value indicating the separation of the currency_symbol, the
sign string, and the value for a negative locally formatted monetary
- quantity.</pre>
+ quantity.
+</pre>
char p_sign_posn
<pre>
Set to a value indicating the positioning of the positive_sign for a
- nonnegative locally formatted monetary quantity.</pre>
+ nonnegative locally formatted monetary quantity.
+</pre>
char n_sign_posn
<pre>
Set to a value indicating the positioning of the negative_sign for a
- negative locally formatted monetary quantity.</pre>
+ negative locally formatted monetary quantity.
+</pre>
char *int_curr_symbol
<pre>
The international currency symbol applicable to the current locale. The
first three characters contain the alphabetic international currency symbol
in accordance with those specified in ISO 4217. The fourth character
(immediately preceding the null character) is the character used to separate
- the international currency symbol from the monetary quantity.</pre>
+ the international currency symbol from the monetary quantity.
+</pre>
char int_frac_digits
<pre>
The number of fractional digits (those after the decimal-point) to be
- displayed in an internationally formatted monetary quantity.</pre>
+ displayed in an internationally formatted monetary quantity.
+</pre>
char int_p_cs_precedes
<pre>
Set to 1 or 0 if the int_curr_symbol respectively precedes or
succeeds the value for a nonnegative internationally formatted monetary
- quantity.</pre>
+ quantity.
+</pre>
char int_n_cs_precedes
<pre>
Set to 1 or 0 if the int_curr_symbol respectively precedes or
succeeds the value for a negative internationally formatted monetary
- quantity.</pre>
+ quantity.
+</pre>
char int_p_sep_by_space
<!--page 245 -->
<pre>
Set to a value indicating the separation of the int_curr_symbol, the
sign string, and the value for a nonnegative internationally formatted
- monetary quantity.</pre>
+ monetary quantity.
+</pre>
char int_n_sep_by_space
<pre>
Set to a value indicating the separation of the int_curr_symbol, the
sign string, and the value for a negative internationally formatted monetary
- quantity.</pre>
+ quantity.
+</pre>
char int_p_sign_posn
<pre>
Set to a value indicating the positioning of the positive_sign for a
- nonnegative internationally formatted monetary quantity.</pre>
+ nonnegative internationally formatted monetary quantity.
+</pre>
char int_n_sign_posn
-<p><!--para 4 -->
<pre>
Set to a value indicating the positioning of the negative_sign for a
- negative internationally formatted monetary quantity.</pre>
+ negative internationally formatted monetary quantity.
+</pre>
+<p><!--para 4 -->
The elements of grouping and mon_grouping are interpreted according to the
following:
CHAR_MAX No further grouping is to be performed.
0 The previous element is to be repeatedly used for the remainder of the
<pre>
- digits.</pre>
+ digits.
+</pre>
other The integer value is the number of digits that compose the current group.
-<p><!--para 5 -->
<pre>
The next element is examined to determine the size of the next group of
- digits before the current group.</pre>
+ digits before the current group.
+</pre>
+<p><!--para 5 -->
The values of p_sep_by_space, n_sep_by_space, int_p_sep_by_space,
and int_n_sep_by_space are interpreted according to the following:
0 No space separates the currency symbol and value.
1 If the currency symbol and sign string are adjacent, a space separates them from the
<pre>
- value; otherwise, a space separates the currency symbol from the value.</pre>
+ value; otherwise, a space separates the currency symbol from the value.
+</pre>
2 If the currency symbol and sign string are adjacent, a space separates them;
<pre>
- otherwise, a space separates the sign string from the value.</pre>
+ otherwise, a space separates the sign string from the value.
+</pre>
For int_p_sep_by_space and int_n_sep_by_space, the fourth character of
int_curr_symbol is used instead of a space.
<p><!--para 6 -->
EXAMPLE 1 The following table illustrates rules which may well be used by four countries to format
monetary quantities.
<pre>
- Local format International format</pre>
+ Local format International format
+</pre>
Country Positive Negative Positive Negative
For these four countries, the respective values for the monetary members of the structure returned by
localeconv could be:
<pre>
- Country1 Country2 Country3 Country4</pre>
+ Country1 Country2 Country3 Country4
+</pre>
mon_decimal_point "," "" "," "."
mon_thousands_sep "." "." "." ","
EXAMPLE 2 The following table illustrates how the cs_precedes, sep_by_space, and sign_posn members
affect the formatted value.
<pre>
- p_sep_by_space</pre>
+ p_sep_by_space
+</pre>
p_cs_precedes p_sign_posn 0 1 2
1 +1.25$ +1.25 $ + <a href="#1.25">1.25</a>$
2 <a href="#1.25">1.25</a>$+ <a href="#1.25">1.25</a> $+ <a href="#1.25">1.25</a>$ +
3 <a href="#1.25">1.25</a>+$ <a href="#1.25">1.25</a> +$ <a href="#1.25">1.25</a>+ $
- 4 <a href="#1.25">1.25</a>$+ <a href="#1.25">1.25</a> $+ <a href="#1.25">1.25</a>$ +</pre>
+ 4 <a href="#1.25">1.25</a>$+ <a href="#1.25">1.25</a> $+ <a href="#1.25">1.25</a>$ +
+</pre>
<!--page 248 -->
<pre>
1 +$1.25 +$ <a href="#1.25">1.25</a> + $1.25
2 $1.25+ $ <a href="#1.25">1.25</a>+ $1.25 +
3 +$1.25 +$ <a href="#1.25">1.25</a> + $1.25
- 4 $+1.25 $+ <a href="#1.25">1.25</a> $ +1.25</pre>
+ 4 $+1.25 $+ <a href="#1.25">1.25</a> $ +1.25
+</pre>
-<a name="7.12" href="#7.12"><h3>7.12 Mathematics <math.h></h3></a>
+<h3><a name="7.12" href="#7.12">7.12 Mathematics <math.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.12"><math.h></a> declares two types and many mathematical functions and defines
several macros. Most synopses specify a family of functions consisting of a principal
The types
<pre>
float_t
- double_t</pre>
+ double_t
+</pre>
are floating types at least as wide as float and double, respectively, and such that
double_t is at least as wide as float_t. If FLT_EVAL_METHOD equals 0,
float_t and double_t are float and double, respectively; if
<p><!--para 3 -->
The macro
<pre>
- HUGE_VAL</pre>
+ HUGE_VAL
+</pre>
expands to a positive double constant expression, not necessarily representable as a
float. The macros
<pre>
HUGE_VALF
- HUGE_VALL</pre>
+ HUGE_VALL
+</pre>
are respectively float and long double analogs of HUGE_VAL.<sup><a href="#note225"><b>225)</b></a></sup>
<p><!--para 4 -->
The macro
<pre>
- INFINITY</pre>
+ INFINITY
+</pre>
expands to a constant expression of type float representing positive or unsigned
infinity, if available; else to a positive constant of type float that overflows at
<p><!--para 5 -->
The macro
<pre>
- NAN</pre>
+ NAN
+</pre>
is defined if and only if the implementation supports quiet NaNs for the float type. It
expands to a constant expression of type float representing a quiet NaN.
<p><!--para 6 -->
FP_NAN
FP_NORMAL
FP_SUBNORMAL
- FP_ZERO</pre>
+ FP_ZERO
+</pre>
represent the mutually exclusive kinds of floating-point values. They expand to integer
constant expressions with distinct values. Additional implementation-defined floating-
point classifications, with macro definitions beginning with FP_ and an uppercase letter,
<p><!--para 7 -->
The macro
<pre>
- FP_FAST_FMA</pre>
+ FP_FAST_FMA
+</pre>
is optionally defined. If defined, it indicates that the fma function generally executes
about as fast as, or faster than, a multiply and an add of double operands.<sup><a href="#note227"><b>227)</b></a></sup> The
macros
<pre>
FP_FAST_FMAF
- FP_FAST_FMAL</pre>
+ FP_FAST_FMAL
+</pre>
are, respectively, float and long double analogs of FP_FAST_FMA. If defined,
these macros expand to the integer constant 1.
<p><!--para 8 -->
The macros
<pre>
FP_ILOGB0
- FP_ILOGBNAN</pre>
+ FP_ILOGBNAN
+</pre>
expand to integer constant expressions whose values are returned by ilogb(x) if x is
zero or NaN, respectively. The value of FP_ILOGB0 shall be either INT_MIN or
-INT_MAX. The value of FP_ILOGBNAN shall be either INT_MAX or INT_MIN.
The macros
<pre>
MATH_ERRNO
- MATH_ERREXCEPT</pre>
+ MATH_ERREXCEPT
+</pre>
expand to the integer constants 1 and 2, respectively; the macro
<pre>
- math_errhandling</pre>
+ math_errhandling
+</pre>
expands to an expression that has type int and the value MATH_ERRNO,
MATH_ERREXCEPT, or the bitwise OR of both. The value of math_errhandling is
constant for the duration of the program. It is unspecified whether
substantially slower.
</small>
-<a name="7.12.1" href="#7.12.1"><h4>7.12.1 Treatment of error conditions</h4></a>
+<h4><a name="7.12.1" href="#7.12.1">7.12.1 Treatment of error conditions</a></h4>
<p><!--para 1 -->
The behavior of each of the functions in <a href="#7.12"><math.h></a> is specified for all representable
values of its input arguments, except where stated otherwise. Each function shall execute
<p><small><a name="note230" href="#note230">230)</a> Math errors are being indicated by the floating-point exception flags rather than by errno.
</small>
-<a name="7.12.2" href="#7.12.2"><h4>7.12.2 The FP_CONTRACT pragma</h4></a>
+<h4><a name="7.12.2" href="#7.12.2">7.12.2 The FP_CONTRACT pragma</a></h4>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- #pragma STDC FP_CONTRACT on-off-switch</pre>
+ #pragma STDC FP_CONTRACT on-off-switch
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The FP_CONTRACT pragma can be used to allow (if the state is ''on'') or disallow (if the
context, the behavior is undefined. The default state (''on'' or ''off'') for the pragma is
implementation-defined.
-<a name="7.12.3" href="#7.12.3"><h4>7.12.3 Classification macros</h4></a>
+<h4><a name="7.12.3" href="#7.12.3">7.12.3 Classification macros</a></h4>
<p><!--para 1 -->
In the synopses in this subclause, real-floating indicates that the argument shall be an
expression of real floating type.
-<a name="7.12.3.1" href="#7.12.3.1"><h5>7.12.3.1 The fpclassify macro</h5></a>
+<h5><a name="7.12.3.1" href="#7.12.3.1">7.12.3.1 The fpclassify macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int fpclassify(real-floating x);</pre>
+ int fpclassify(real-floating x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fpclassify macro classifies its argument value as NaN, infinite, normal,
become subnormal when converted to double, and zero when converted to float.
</small>
-<a name="7.12.3.2" href="#7.12.3.2"><h5>7.12.3.2 The isfinite macro</h5></a>
+<h5><a name="7.12.3.2" href="#7.12.3.2">7.12.3.2 The isfinite macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int isfinite(real-floating x);</pre>
+ int isfinite(real-floating x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isfinite macro determines whether its argument has a finite value (zero,
The isfinite macro returns a nonzero value if and only if its argument has a finite
value.
-<a name="7.12.3.3" href="#7.12.3.3"><h5>7.12.3.3 The isinf macro</h5></a>
+<h5><a name="7.12.3.3" href="#7.12.3.3">7.12.3.3 The isinf macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int isinf(real-floating x);</pre>
+ int isinf(real-floating x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isinf macro determines whether its argument value is an infinity (positive or
The isinf macro returns a nonzero value if and only if its argument has an infinite
value.
-<a name="7.12.3.4" href="#7.12.3.4"><h5>7.12.3.4 The isnan macro</h5></a>
+<h5><a name="7.12.3.4" href="#7.12.3.4">7.12.3.4 The isnan macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int isnan(real-floating x);</pre>
+ int isnan(real-floating x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isnan macro determines whether its argument value is a NaN. First, an argument
NaNs in the evaluation type but not in the semantic type.
</small>
-<a name="7.12.3.5" href="#7.12.3.5"><h5>7.12.3.5 The isnormal macro</h5></a>
+<h5><a name="7.12.3.5" href="#7.12.3.5">7.12.3.5 The isnormal macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int isnormal(real-floating x);</pre>
+ int isnormal(real-floating x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isnormal macro determines whether its argument value is normal (neither zero,
The isnormal macro returns a nonzero value if and only if its argument has a normal
value.
-<a name="7.12.3.6" href="#7.12.3.6"><h5>7.12.3.6 The signbit macro</h5></a>
+<h5><a name="7.12.3.6" href="#7.12.3.6">7.12.3.6 The signbit macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int signbit(real-floating x);</pre>
+ int signbit(real-floating x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The signbit macro determines whether the sign of its argument value is negative.<sup><a href="#note233"><b>233)</b></a></sup>
unsigned, it is treated as positive.
</small>
-<a name="7.12.4" href="#7.12.4"><h4>7.12.4 Trigonometric functions</h4></a>
+<h4><a name="7.12.4" href="#7.12.4">7.12.4 Trigonometric functions</a></h4>
-<a name="7.12.4.1" href="#7.12.4.1"><h5>7.12.4.1 The acos functions</h5></a>
+<h5><a name="7.12.4.1" href="#7.12.4.1">7.12.4.1 The acos functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double acos(double x);
float acosf(float x);
- long double acosl(long double x);</pre>
+ long double acosl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The acos functions compute the principal value of the arc cosine of x. A domain error
<p><!--para 3 -->
The acos functions return arccos x in the interval [0, pi ] radians.
-<a name="7.12.4.2" href="#7.12.4.2"><h5>7.12.4.2 The asin functions</h5></a>
+<h5><a name="7.12.4.2" href="#7.12.4.2">7.12.4.2 The asin functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double asin(double x);
float asinf(float x);
- long double asinl(long double x);</pre>
+ long double asinl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The asin functions compute the principal value of the arc sine of x. A domain error
<p><!--para 3 -->
The asin functions return arcsin x in the interval [-pi /2, +pi /2] radians.
-<a name="7.12.4.3" href="#7.12.4.3"><h5>7.12.4.3 The atan functions</h5></a>
+<h5><a name="7.12.4.3" href="#7.12.4.3">7.12.4.3 The atan functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double atan(double x);
float atanf(float x);
- long double atanl(long double x);</pre>
+ long double atanl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The atan functions compute the principal value of the arc tangent of x.
<p><!--para 3 -->
The atan functions return arctan x in the interval [-pi /2, +pi /2] radians.
-<a name="7.12.4.4" href="#7.12.4.4"><h5>7.12.4.4 The atan2 functions</h5></a>
+<h5><a name="7.12.4.4" href="#7.12.4.4">7.12.4.4 The atan2 functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double atan2(double y, double x);
float atan2f(float y, float x);
- long double atan2l(long double y, long double x);</pre>
+ long double atan2l(long double y, long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The atan2 functions compute the value of the arc tangent of y/x, using the signs of both
<p><!--para 3 -->
The atan2 functions return arctan y/x in the interval [-pi , +pi ] radians.
-<a name="7.12.4.5" href="#7.12.4.5"><h5>7.12.4.5 The cos functions</h5></a>
+<h5><a name="7.12.4.5" href="#7.12.4.5">7.12.4.5 The cos functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double cos(double x);
float cosf(float x);
- long double cosl(long double x);</pre>
+ long double cosl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cos functions compute the cosine of x (measured in radians).
<p><!--para 3 -->
The cos functions return cos x.
-<a name="7.12.4.6" href="#7.12.4.6"><h5>7.12.4.6 The sin functions</h5></a>
+<h5><a name="7.12.4.6" href="#7.12.4.6">7.12.4.6 The sin functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double sin(double x);
float sinf(float x);
- long double sinl(long double x);</pre>
+ long double sinl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The sin functions compute the sine of x (measured in radians).
<p><!--para 3 -->
The sin functions return sin x.
-<a name="7.12.4.7" href="#7.12.4.7"><h5>7.12.4.7 The tan functions</h5></a>
+<h5><a name="7.12.4.7" href="#7.12.4.7">7.12.4.7 The tan functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double tan(double x);
float tanf(float x);
- long double tanl(long double x);</pre>
+ long double tanl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tan functions return the tangent of x (measured in radians).
<p><!--para 3 -->
The tan functions return tan x.
-<a name="7.12.5" href="#7.12.5"><h4>7.12.5 Hyperbolic functions</h4></a>
+<h4><a name="7.12.5" href="#7.12.5">7.12.5 Hyperbolic functions</a></h4>
-<a name="7.12.5.1" href="#7.12.5.1"><h5>7.12.5.1 The acosh functions</h5></a>
+<h5><a name="7.12.5.1" href="#7.12.5.1">7.12.5.1 The acosh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double acosh(double x);
float acoshf(float x);
- long double acoshl(long double x);</pre>
+ long double acoshl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The acosh functions compute the (nonnegative) arc hyperbolic cosine of x. A domain
<p><!--para 3 -->
The acosh functions return arcosh x in the interval [0, +(inf)].
-<a name="7.12.5.2" href="#7.12.5.2"><h5>7.12.5.2 The asinh functions</h5></a>
+<h5><a name="7.12.5.2" href="#7.12.5.2">7.12.5.2 The asinh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double asinh(double x);
float asinhf(float x);
- long double asinhl(long double x);</pre>
+ long double asinhl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The asinh functions compute the arc hyperbolic sine of x.
<p><!--para 3 -->
The asinh functions return arsinh x.
-<a name="7.12.5.3" href="#7.12.5.3"><h5>7.12.5.3 The atanh functions</h5></a>
+<h5><a name="7.12.5.3" href="#7.12.5.3">7.12.5.3 The atanh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double atanh(double x);
float atanhf(float x);
- long double atanhl(long double x);</pre>
+ long double atanhl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The atanh functions compute the arc hyperbolic tangent of x. A domain error occurs
<p><!--para 3 -->
The atanh functions return artanh x.
-<a name="7.12.5.4" href="#7.12.5.4"><h5>7.12.5.4 The cosh functions</h5></a>
+<h5><a name="7.12.5.4" href="#7.12.5.4">7.12.5.4 The cosh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double cosh(double x);
float coshf(float x);
- long double coshl(long double x);</pre>
+ long double coshl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cosh functions compute the hyperbolic cosine of x. A range error occurs if the
<p><!--para 3 -->
The cosh functions return cosh x.
-<a name="7.12.5.5" href="#7.12.5.5"><h5>7.12.5.5 The sinh functions</h5></a>
+<h5><a name="7.12.5.5" href="#7.12.5.5">7.12.5.5 The sinh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double sinh(double x);
float sinhf(float x);
- long double sinhl(long double x);</pre>
+ long double sinhl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The sinh functions compute the hyperbolic sine of x. A range error occurs if the
<p><!--para 3 -->
The sinh functions return sinh x.
-<a name="7.12.5.6" href="#7.12.5.6"><h5>7.12.5.6 The tanh functions</h5></a>
+<h5><a name="7.12.5.6" href="#7.12.5.6">7.12.5.6 The tanh functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double tanh(double x);
float tanhf(float x);
- long double tanhl(long double x);</pre>
+ long double tanhl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tanh functions compute the hyperbolic tangent of x.
<p><!--para 3 -->
The tanh functions return tanh x.
-<a name="7.12.6" href="#7.12.6"><h4>7.12.6 Exponential and logarithmic functions</h4></a>
+<h4><a name="7.12.6" href="#7.12.6">7.12.6 Exponential and logarithmic functions</a></h4>
-<a name="7.12.6.1" href="#7.12.6.1"><h5>7.12.6.1 The exp functions</h5></a>
+<h5><a name="7.12.6.1" href="#7.12.6.1">7.12.6.1 The exp functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double exp(double x);
float expf(float x);
- long double expl(long double x);</pre>
+ long double expl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The exp functions compute the base-e exponential of x. A range error occurs if the
<p><!--para 3 -->
The exp functions return ex .
-<a name="7.12.6.2" href="#7.12.6.2"><h5>7.12.6.2 The exp2 functions</h5></a>
+<h5><a name="7.12.6.2" href="#7.12.6.2">7.12.6.2 The exp2 functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double exp2(double x);
float exp2f(float x);
- long double exp2l(long double x);</pre>
+ long double exp2l(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The exp2 functions compute the base-2 exponential of x. A range error occurs if the
<p><!--para 3 -->
The exp2 functions return 2x .
-<a name="7.12.6.3" href="#7.12.6.3"><h5>7.12.6.3 The expm1 functions</h5></a>
+<h5><a name="7.12.6.3" href="#7.12.6.3">7.12.6.3 The expm1 functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double expm1(double x);
float expm1f(float x);
- long double expm1l(long double x);</pre>
+ long double expm1l(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The expm1 functions compute the base-e exponential of the argument, minus 1. A range
<p><small><a name="note234" href="#note234">234)</a> For small magnitude x, expm1(x) is expected to be more accurate than exp(x) - 1.
</small>
-<a name="7.12.6.4" href="#7.12.6.4"><h5>7.12.6.4 The frexp functions</h5></a>
+<h5><a name="7.12.6.4" href="#7.12.6.4">7.12.6.4 The frexp functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double frexp(double value, int *exp);
float frexpf(float value, int *exp);
- long double frexpl(long double value, int *exp);</pre>
+ long double frexpl(long double value, int *exp);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The frexp functions break a floating-point number into a normalized fraction and an
<!--page 261 -->
-<a name="7.12.6.5" href="#7.12.6.5"><h5>7.12.6.5 The ilogb functions</h5></a>
+<h5><a name="7.12.6.5" href="#7.12.6.5">7.12.6.5 The ilogb functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
int ilogb(double x);
int ilogbf(float x);
- int ilogbl(long double x);</pre>
+ int ilogbl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ilogb functions extract the exponent of x as a signed int value. If x is zero they
The ilogb functions return the exponent of x as a signed int value.
<p><b> Forward references</b>: the logb functions (<a href="#7.12.6.11">7.12.6.11</a>).
-<a name="7.12.6.6" href="#7.12.6.6"><h5>7.12.6.6 The ldexp functions</h5></a>
+<h5><a name="7.12.6.6" href="#7.12.6.6">7.12.6.6 The ldexp functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double ldexp(double x, int exp);
float ldexpf(float x, int exp);
- long double ldexpl(long double x, int exp);</pre>
+ long double ldexpl(long double x, int exp);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ldexp functions multiply a floating-point number by an integral power of 2. A
<p><!--para 3 -->
The ldexp functions return x x 2exp .
-<a name="7.12.6.7" href="#7.12.6.7"><h5>7.12.6.7 The log functions</h5></a>
+<h5><a name="7.12.6.7" href="#7.12.6.7">7.12.6.7 The log functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<!--page 262 -->
#include <a href="#7.12"><math.h></a>
double log(double x);
float logf(float x);
- long double logl(long double x);</pre>
+ long double logl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The log functions compute the base-e (natural) logarithm of x. A domain error occurs if
<p><!--para 3 -->
The log functions return loge x.
-<a name="7.12.6.8" href="#7.12.6.8"><h5>7.12.6.8 The log10 functions</h5></a>
+<h5><a name="7.12.6.8" href="#7.12.6.8">7.12.6.8 The log10 functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double log10(double x);
float log10f(float x);
- long double log10l(long double x);</pre>
+ long double log10l(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The log10 functions compute the base-10 (common) logarithm of x. A domain error
<p><!--para 3 -->
The log10 functions return log10 x.
-<a name="7.12.6.9" href="#7.12.6.9"><h5>7.12.6.9 The log1p functions</h5></a>
+<h5><a name="7.12.6.9" href="#7.12.6.9">7.12.6.9 The log1p functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double log1p(double x);
float log1pf(float x);
- long double log1pl(long double x);</pre>
+ long double log1pl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The log1p functions compute the base-e (natural) logarithm of 1 plus the argument.<sup><a href="#note235"><b>235)</b></a></sup>
<p><small><a name="note235" href="#note235">235)</a> For small magnitude x, log1p(x) is expected to be more accurate than log(1 + x).
</small>
-<a name="7.12.6.10" href="#7.12.6.10"><h5>7.12.6.10 The log2 functions</h5></a>
+<h5><a name="7.12.6.10" href="#7.12.6.10">7.12.6.10 The log2 functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double log2(double x);
float log2f(float x);
- long double log2l(long double x);</pre>
+ long double log2l(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The log2 functions compute the base-2 logarithm of x. A domain error occurs if the
<p><!--para 3 -->
The log2 functions return log2 x.
-<a name="7.12.6.11" href="#7.12.6.11"><h5>7.12.6.11 The logb functions</h5></a>
+<h5><a name="7.12.6.11" href="#7.12.6.11">7.12.6.11 The logb functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double logb(double x);
float logbf(float x);
- long double logbl(long double x);</pre>
+ long double logbl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The logb functions extract the exponent of x, as a signed integer value in floating-point
format. If x is subnormal it is treated as though it were normalized; thus, for positive
finite x,
<pre>
- 1 <= x x FLT_RADIX-logb(x) < FLT_RADIX</pre>
+ 1 <= x x FLT_RADIX-logb(x) < FLT_RADIX
+</pre>
A domain error or pole error may occur if the argument is zero.
<h6>Returns</h6>
<p><!--para 3 -->
The logb functions return the signed exponent of x.
-<a name="7.12.6.12" href="#7.12.6.12"><h5>7.12.6.12 The modf functions</h5></a>
+<h5><a name="7.12.6.12" href="#7.12.6.12">7.12.6.12 The modf functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double modf(double value, double *iptr);
float modff(float value, float *iptr);
- long double modfl(long double value, long double *iptr);</pre>
+ long double modfl(long double value, long double *iptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The modf functions break the argument value into integral and fractional parts, each of
<p><!--para 3 -->
The modf functions return the signed fractional part of value.
-<a name="7.12.6.13" href="#7.12.6.13"><h5>7.12.6.13 The scalbn and scalbln functions</h5></a>
+<h5><a name="7.12.6.13" href="#7.12.6.13">7.12.6.13 The scalbn and scalbln functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
long double scalbnl(long double x, int n);
double scalbln(double x, long int n);
float scalblnf(float x, long int n);
- long double scalblnl(long double x, long int n);</pre>
+ long double scalblnl(long double x, long int n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The scalbn and scalbln functions compute x x FLT_RADIXn efficiently, not
<p><!--para 3 -->
The scalbn and scalbln functions return x x FLT_RADIXn .
-<a name="7.12.7" href="#7.12.7"><h4>7.12.7 Power and absolute-value functions</h4></a>
+<h4><a name="7.12.7" href="#7.12.7">7.12.7 Power and absolute-value functions</a></h4>
-<a name="7.12.7.1" href="#7.12.7.1"><h5>7.12.7.1 The cbrt functions</h5></a>
+<h5><a name="7.12.7.1" href="#7.12.7.1">7.12.7.1 The cbrt functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double cbrt(double x);
float cbrtf(float x);
- long double cbrtl(long double x);</pre>
+ long double cbrtl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cbrt functions compute the real cube root of x.
The cbrt functions return x1/3 .
<!--page 265 -->
-<a name="7.12.7.2" href="#7.12.7.2"><h5>7.12.7.2 The fabs functions</h5></a>
+<h5><a name="7.12.7.2" href="#7.12.7.2">7.12.7.2 The fabs functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double fabs(double x);
float fabsf(float x);
- long double fabsl(long double x);</pre>
+ long double fabsl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fabs functions compute the absolute value of a floating-point number x.
<p><!--para 3 -->
The fabs functions return | x |.
-<a name="7.12.7.3" href="#7.12.7.3"><h5>7.12.7.3 The hypot functions</h5></a>
+<h5><a name="7.12.7.3" href="#7.12.7.3">7.12.7.3 The hypot functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double hypot(double x, double y);
float hypotf(float x, float y);
- long double hypotl(long double x, long double y);</pre>
+ long double hypotl(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The hypot functions compute the square root of the sum of the squares of x and y,
The hypot functions return (sqrt)x2 + y2 .
<pre>
-
- -----</pre>
+ -----
+</pre>
-<a name="7.12.7.4" href="#7.12.7.4"><h5>7.12.7.4 The pow functions</h5></a>
+<h5><a name="7.12.7.4" href="#7.12.7.4">7.12.7.4 The pow functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double pow(double x, double y);
float powf(float x, float y);
- long double powl(long double x, long double y);</pre>
+ long double powl(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The pow functions compute x raised to the power y. A domain error occurs if x is finite
<p><!--para 3 -->
The pow functions return xy .
-<a name="7.12.7.5" href="#7.12.7.5"><h5>7.12.7.5 The sqrt functions</h5></a>
+<h5><a name="7.12.7.5" href="#7.12.7.5">7.12.7.5 The sqrt functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double sqrt(double x);
float sqrtf(float x);
- long double sqrtl(long double x);</pre>
+ long double sqrtl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The sqrt functions compute the nonnegative square root of x. A domain error occurs if
The sqrt functions return (sqrt)x.
<pre>
-
- -</pre>
+ -
+</pre>
-<a name="7.12.8" href="#7.12.8"><h4>7.12.8 Error and gamma functions</h4></a>
+<h4><a name="7.12.8" href="#7.12.8">7.12.8 Error and gamma functions</a></h4>
-<a name="7.12.8.1" href="#7.12.8.1"><h5>7.12.8.1 The erf functions</h5></a>
+<h5><a name="7.12.8.1" href="#7.12.8.1">7.12.8.1 The erf functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double erf(double x);
float erff(float x);
- long double erfl(long double x);</pre>
+ long double erfl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The erf functions compute the error function of x.
<pre>
2 x
(integral) e-t dt.
- 2</pre>
+ 2
+</pre>
The erf functions return erf x =
<pre>
(sqrt)pi
-
- - 0</pre>
+ - 0
+</pre>
-<a name="7.12.8.2" href="#7.12.8.2"><h5>7.12.8.2 The erfc functions</h5></a>
+<h5><a name="7.12.8.2" href="#7.12.8.2">7.12.8.2 The erfc functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double erfc(double x);
float erfcf(float x);
- long double erfcl(long double x);</pre>
+ long double erfcl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The erfc functions compute the complementary error function of x. A range error
<pre>
2 (inf)
(integral) e-t dt.
- 2</pre>
+ 2
+</pre>
The erfc functions return erfc x = 1 - erf x =
<pre>
(sqrt)pi
-
- - x</pre>
+ - x
+</pre>
-<a name="7.12.8.3" href="#7.12.8.3"><h5>7.12.8.3 The lgamma functions</h5></a>
+<h5><a name="7.12.8.3" href="#7.12.8.3">7.12.8.3 The lgamma functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double lgamma(double x);
float lgammaf(float x);
- long double lgammal(long double x);</pre>
+ long double lgammal(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The lgamma functions compute the natural logarithm of the absolute value of gamma of
<p><!--para 3 -->
The lgamma functions return loge | (Gamma)(x) |.
-<a name="7.12.8.4" href="#7.12.8.4"><h5>7.12.8.4 The tgamma functions</h5></a>
+<h5><a name="7.12.8.4" href="#7.12.8.4">7.12.8.4 The tgamma functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double tgamma(double x);
float tgammaf(float x);
- long double tgammal(long double x);</pre>
+ long double tgammal(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tgamma functions compute the gamma function of x. A domain error or pole error
The tgamma functions return (Gamma)(x).
<!--page 268 -->
-<a name="7.12.9" href="#7.12.9"><h4>7.12.9 Nearest integer functions</h4></a>
+<h4><a name="7.12.9" href="#7.12.9">7.12.9 Nearest integer functions</a></h4>
-<a name="7.12.9.1" href="#7.12.9.1"><h5>7.12.9.1 The ceil functions</h5></a>
+<h5><a name="7.12.9.1" href="#7.12.9.1">7.12.9.1 The ceil functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double ceil(double x);
float ceilf(float x);
- long double ceill(long double x);</pre>
+ long double ceill(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ceil functions compute the smallest integer value not less than x.
<p><!--para 3 -->
The ceil functions return [^x^], expressed as a floating-point number.
-<a name="7.12.9.2" href="#7.12.9.2"><h5>7.12.9.2 The floor functions</h5></a>
+<h5><a name="7.12.9.2" href="#7.12.9.2">7.12.9.2 The floor functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double floor(double x);
float floorf(float x);
- long double floorl(long double x);</pre>
+ long double floorl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The floor functions compute the largest integer value not greater than x.
<p><!--para 3 -->
The floor functions return [_x_], expressed as a floating-point number.
-<a name="7.12.9.3" href="#7.12.9.3"><h5>7.12.9.3 The nearbyint functions</h5></a>
+<h5><a name="7.12.9.3" href="#7.12.9.3">7.12.9.3 The nearbyint functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double nearbyint(double x);
float nearbyintf(float x);
- long double nearbyintl(long double x);</pre>
+ long double nearbyintl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The nearbyint functions round their argument to an integer value in floating-point
<p><!--para 3 -->
The nearbyint functions return the rounded integer value.
-<a name="7.12.9.4" href="#7.12.9.4"><h5>7.12.9.4 The rint functions</h5></a>
+<h5><a name="7.12.9.4" href="#7.12.9.4">7.12.9.4 The rint functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double rint(double x);
float rintf(float x);
- long double rintl(long double x);</pre>
+ long double rintl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The rint functions differ from the nearbyint functions (<a href="#7.12.9.3">7.12.9.3</a>) only in that the
<p><!--para 3 -->
The rint functions return the rounded integer value.
-<a name="7.12.9.5" href="#7.12.9.5"><h5>7.12.9.5 The lrint and llrint functions</h5></a>
+<h5><a name="7.12.9.5" href="#7.12.9.5">7.12.9.5 The lrint and llrint functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
long int lrintl(long double x);
long long int llrint(double x);
long long int llrintf(float x);
- long long int llrintl(long double x);</pre>
+ long long int llrintl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The lrint and llrint functions round their argument to the nearest integer value,
The lrint and llrint functions return the rounded integer value.
<!--page 270 -->
-<a name="7.12.9.6" href="#7.12.9.6"><h5>7.12.9.6 The round functions</h5></a>
+<h5><a name="7.12.9.6" href="#7.12.9.6">7.12.9.6 The round functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double round(double x);
float roundf(float x);
- long double roundl(long double x);</pre>
+ long double roundl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The round functions round their argument to the nearest integer value in floating-point
<p><!--para 3 -->
The round functions return the rounded integer value.
-<a name="7.12.9.7" href="#7.12.9.7"><h5>7.12.9.7 The lround and llround functions</h5></a>
+<h5><a name="7.12.9.7" href="#7.12.9.7">7.12.9.7 The lround and llround functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
long int lroundl(long double x);
long long int llround(double x);
long long int llroundf(float x);
- long long int llroundl(long double x);</pre>
+ long long int llroundl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The lround and llround functions round their argument to the nearest integer value,
<p><!--para 3 -->
The lround and llround functions return the rounded integer value.
-<a name="7.12.9.8" href="#7.12.9.8"><h5>7.12.9.8 The trunc functions</h5></a>
+<h5><a name="7.12.9.8" href="#7.12.9.8">7.12.9.8 The trunc functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<!--page 271 -->
#include <a href="#7.12"><math.h></a>
double trunc(double x);
float truncf(float x);
- long double truncl(long double x);</pre>
+ long double truncl(long double x);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The trunc functions round their argument to the integer value, in floating format,
<p><!--para 3 -->
The trunc functions return the truncated integer value.
-<a name="7.12.10" href="#7.12.10"><h4>7.12.10 Remainder functions</h4></a>
+<h4><a name="7.12.10" href="#7.12.10">7.12.10 Remainder functions</a></h4>
-<a name="7.12.10.1" href="#7.12.10.1"><h5>7.12.10.1 The fmod functions</h5></a>
+<h5><a name="7.12.10.1" href="#7.12.10.1">7.12.10.1 The fmod functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double fmod(double x, double y);
float fmodf(float x, float y);
- long double fmodl(long double x, long double y);</pre>
+ long double fmodl(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fmod functions compute the floating-point remainder of x/y.
whether a domain error occurs or the fmod functions return zero is implementation-
defined.
-<a name="7.12.10.2" href="#7.12.10.2"><h5>7.12.10.2 The remainder functions</h5></a>
+<h5><a name="7.12.10.2" href="#7.12.10.2">7.12.10.2 The remainder functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double remainder(double x, double y);
float remainderf(float x, float y);
- long double remainderl(long double x, long double y);</pre>
+ long double remainderl(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The remainder functions compute the remainder x REM y required by IEC 60559.<sup><a href="#note236"><b>236)</b></a></sup>
all implementations.
</small>
-<a name="7.12.10.3" href="#7.12.10.3"><h5>7.12.10.3 The remquo functions</h5></a>
+<h5><a name="7.12.10.3" href="#7.12.10.3">7.12.10.3 The remquo functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
double remquo(double x, double y, int *quo);
float remquof(float x, float y, int *quo);
long double remquol(long double x, long double y,
- int *quo);</pre>
+ int *quo);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The remquo functions compute the same remainder as the remainder functions. In
pointed to by quo is unspecified and whether a domain error occurs or the functions
return zero is implementation defined.
-<a name="7.12.11" href="#7.12.11"><h4>7.12.11 Manipulation functions</h4></a>
+<h4><a name="7.12.11" href="#7.12.11">7.12.11 Manipulation functions</a></h4>
-<a name="7.12.11.1" href="#7.12.11.1"><h5>7.12.11.1 The copysign functions</h5></a>
+<h5><a name="7.12.11.1" href="#7.12.11.1">7.12.11.1 The copysign functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double copysign(double x, double y);
float copysignf(float x, float y);
- long double copysignl(long double x, long double y);</pre>
+ long double copysignl(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The copysign functions produce a value with the magnitude of x and the sign of y.
The copysign functions return a value with the magnitude of x and the sign of y.
<!--page 273 -->
-<a name="7.12.11.2" href="#7.12.11.2"><h5>7.12.11.2 The nan functions</h5></a>
+<h5><a name="7.12.11.2" href="#7.12.11.2">7.12.11.2 The nan functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double nan(const char *tagp);
float nanf(const char *tagp);
- long double nanl(const char *tagp);</pre>
+ long double nanl(const char *tagp);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The call nan("n-char-sequence") is equivalent to strtod("NAN(n-char-
If the implementation does not support quiet NaNs, the functions return zero.
<p><b> Forward references</b>: the strtod, strtof, and strtold functions (<a href="#7.22.1.3">7.22.1.3</a>).
-<a name="7.12.11.3" href="#7.12.11.3"><h5>7.12.11.3 The nextafter functions</h5></a>
+<h5><a name="7.12.11.3" href="#7.12.11.3">7.12.11.3 The nextafter functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double nextafter(double x, double y);
float nextafterf(float x, float y);
- long double nextafterl(long double x, long double y);</pre>
+ long double nextafterl(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The nextafter functions determine the next representable value, in the type of the
function.
</small>
-<a name="7.12.11.4" href="#7.12.11.4"><h5>7.12.11.4 The nexttoward functions</h5></a>
+<h5><a name="7.12.11.4" href="#7.12.11.4">7.12.11.4 The nexttoward functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double nexttoward(double x, long double y);
float nexttowardf(float x, long double y);
- long double nexttowardl(long double x, long double y);</pre>
+ long double nexttowardl(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The nexttoward functions are equivalent to the nextafter functions except that the
range or precision in a floating second argument.
</small>
-<a name="7.12.12" href="#7.12.12"><h4>7.12.12 Maximum, minimum, and positive difference functions</h4></a>
+<h4><a name="7.12.12" href="#7.12.12">7.12.12 Maximum, minimum, and positive difference functions</a></h4>
-<a name="7.12.12.1" href="#7.12.12.1"><h5>7.12.12.1 The fdim functions</h5></a>
+<h5><a name="7.12.12.1" href="#7.12.12.1">7.12.12.1 The fdim functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double fdim(double x, double y);
float fdimf(float x, float y);
- long double fdiml(long double x, long double y);</pre>
+ long double fdiml(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fdim functions determine the positive difference between their arguments:
<pre>
{x - y if x > y
{
- {+0 if x <= y</pre>
+ {+0 if x <= y
+</pre>
A range error may occur.
<h6>Returns</h6>
<p><!--para 3 -->
The fdim functions return the positive difference value.
-<a name="7.12.12.2" href="#7.12.12.2"><h5>7.12.12.2 The fmax functions</h5></a>
+<h5><a name="7.12.12.2" href="#7.12.12.2">7.12.12.2 The fmax functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double fmax(double x, double y);
float fmaxf(float x, float y);
- long double fmaxl(long double x, long double y);</pre>
+ long double fmaxl(long double x, long double y);
+</pre>
fmax functions choose the numeric value. See <a href="#F.10.9.2">F.10.9.2</a>.
</small>
-<a name="7.12.12.3" href="#7.12.12.3"><h5>7.12.12.3 The fmin functions</h5></a>
+<h5><a name="7.12.12.3" href="#7.12.12.3">7.12.12.3 The fmin functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
double fmin(double x, double y);
float fminf(float x, float y);
- long double fminl(long double x, long double y);</pre>
+ long double fminl(long double x, long double y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fmin functions determine the minimum numeric value of their arguments.<sup><a href="#note240"><b>240)</b></a></sup>
<p><small><a name="note240" href="#note240">240)</a> The fmin functions are analogous to the fmax functions in their treatment of NaNs.
</small>
-<a name="7.12.13" href="#7.12.13"><h4>7.12.13 Floating multiply-add</h4></a>
+<h4><a name="7.12.13" href="#7.12.13">7.12.13 Floating multiply-add</a></h4>
-<a name="7.12.13.1" href="#7.12.13.1"><h5>7.12.13.1 The fma functions</h5></a>
+<h5><a name="7.12.13.1" href="#7.12.13.1">7.12.13.1 The fma functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
double fma(double x, double y, double z);
float fmaf(float x, float y, float z);
long double fmal(long double x, long double y,
- long double z);</pre>
+ long double z);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fma functions compute (x x y) + z, rounded as one ternary operation: they compute
<!--page 276 -->
-<a name="7.12.14" href="#7.12.14"><h4>7.12.14 Comparison macros</h4></a>
+<h4><a name="7.12.14" href="#7.12.14">7.12.14 Comparison macros</a></h4>
<p><!--para 1 -->
The relational and equality operators support the usual mathematical relationships
between numeric values. For any ordered pair of numeric values exactly one of the
type is unspecified.
</small>
-<a name="7.12.14.1" href="#7.12.14.1"><h5>7.12.14.1 The isgreater macro</h5></a>
+<h5><a name="7.12.14.1" href="#7.12.14.1">7.12.14.1 The isgreater macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int isgreater(real-floating x, real-floating y);</pre>
+ int isgreater(real-floating x, real-floating y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isgreater macro determines whether its first argument is greater than its second
<p><!--para 3 -->
The isgreater macro returns the value of (x) > (y).
-<a name="7.12.14.2" href="#7.12.14.2"><h5>7.12.14.2 The isgreaterequal macro</h5></a>
+<h5><a name="7.12.14.2" href="#7.12.14.2">7.12.14.2 The isgreaterequal macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int isgreaterequal(real-floating x, real-floating y);</pre>
+ int isgreaterequal(real-floating x, real-floating y);
+</pre>
<p><!--para 3 -->
The isgreaterequal macro returns the value of (x) >= (y).
-<a name="7.12.14.3" href="#7.12.14.3"><h5>7.12.14.3 The isless macro</h5></a>
+<h5><a name="7.12.14.3" href="#7.12.14.3">7.12.14.3 The isless macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int isless(real-floating x, real-floating y);</pre>
+ int isless(real-floating x, real-floating y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isless macro determines whether its first argument is less than its second
<p><!--para 3 -->
The isless macro returns the value of (x) < (y).
-<a name="7.12.14.4" href="#7.12.14.4"><h5>7.12.14.4 The islessequal macro</h5></a>
+<h5><a name="7.12.14.4" href="#7.12.14.4">7.12.14.4 The islessequal macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int islessequal(real-floating x, real-floating y);</pre>
+ int islessequal(real-floating x, real-floating y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The islessequal macro determines whether its first argument is less than or equal to
The islessequal macro returns the value of (x) <= (y).
<!--page 278 -->
-<a name="7.12.14.5" href="#7.12.14.5"><h5>7.12.14.5 The islessgreater macro</h5></a>
+<h5><a name="7.12.14.5" href="#7.12.14.5">7.12.14.5 The islessgreater macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int islessgreater(real-floating x, real-floating y);</pre>
+ int islessgreater(real-floating x, real-floating y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The islessgreater macro determines whether its first argument is less than or
<p><!--para 3 -->
The islessgreater macro returns the value of (x) < (y) || (x) > (y).
-<a name="7.12.14.6" href="#7.12.14.6"><h5>7.12.14.6 The isunordered macro</h5></a>
+<h5><a name="7.12.14.6" href="#7.12.14.6">7.12.14.6 The isunordered macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.12"><math.h></a>
- int isunordered(real-floating x, real-floating y);</pre>
+ int isunordered(real-floating x, real-floating y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The isunordered macro determines whether its arguments are unordered.
The isunordered macro returns 1 if its arguments are unordered and 0 otherwise.
<!--page 279 -->
-<a name="7.13" href="#7.13"><h3>7.13 Nonlocal jumps <setjmp.h></h3></a>
+<h3><a name="7.13" href="#7.13">7.13 Nonlocal jumps <setjmp.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.13"><setjmp.h></a> defines the macro setjmp, and declares one function and
one type, for bypassing the normal function call and return discipline.<sup><a href="#note244"><b>244)</b></a></sup>
<p><!--para 2 -->
The type declared is
<pre>
- jmp_buf</pre>
+ jmp_buf
+</pre>
which is an array type suitable for holding the information needed to restore a calling
environment. The environment of a call to the setjmp macro consists of information
sufficient for a call to the longjmp function to return execution to the correct block and
a program.
</small>
-<a name="7.13.1" href="#7.13.1"><h4>7.13.1 Save calling environment</h4></a>
+<h4><a name="7.13.1" href="#7.13.1">7.13.1 Save calling environment</a></h4>
-<a name="7.13.1.1" href="#7.13.1.1"><h5>7.13.1.1 The setjmp macro</h5></a>
+<h5><a name="7.13.1.1" href="#7.13.1.1">7.13.1.1 The setjmp macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.13"><setjmp.h></a>
- int setjmp(jmp_buf env);</pre>
+ int setjmp(jmp_buf env);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The setjmp macro saves its calling environment in its jmp_buf argument for later use
If the return is from a direct invocation, the setjmp macro returns the value zero. If the
return is from a call to the longjmp function, the setjmp macro returns a nonzero
value.
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 4 -->
An invocation of the setjmp macro shall appear only in one of the following contexts:
<ul>
<p><!--para 5 -->
If the invocation appears in any other context, the behavior is undefined.
-<a name="7.13.2" href="#7.13.2"><h4>7.13.2 Restore calling environment</h4></a>
+<h4><a name="7.13.2" href="#7.13.2">7.13.2 Restore calling environment</a></h4>
-<a name="7.13.2.1" href="#7.13.2.1"><h5>7.13.2.1 The longjmp function</h5></a>
+<h5><a name="7.13.2.1" href="#7.13.2.1">7.13.2.1 The longjmp function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.13"><setjmp.h></a>
- _Noreturn void longjmp(jmp_buf env, int val);</pre>
+ _Noreturn void longjmp(jmp_buf env, int val);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The longjmp function restores the environment saved by the most recent invocation of
{
int b[n]; // b may remain allocated
longjmp(buf, 2); // might cause memory loss
- }</pre>
+ }
+</pre>
<h6>footnotes</h6>
<p><small><a name="note245" href="#note245">245)</a> For example, by executing a return statement or because another longjmp call has caused a
<p><small><a name="note246" href="#note246">246)</a> This includes, but is not limited to, the floating-point status flags and the state of open files.
</small>
-<a name="7.14" href="#7.14"><h3>7.14 Signal handling <signal.h></h3></a>
+<h3><a name="7.14" href="#7.14">7.14 Signal handling <signal.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.14"><signal.h></a> declares a type and two functions and defines several macros,
for handling various signals (conditions that may be reported during program execution).
<p><!--para 2 -->
The type defined is
<pre>
- sig_atomic_t</pre>
+ sig_atomic_t
+</pre>
which is the (possibly volatile-qualified) integer type of an object that can be accessed as
an atomic entity, even in the presence of asynchronous interrupts.
<p><!--para 3 -->
<pre>
SIG_DFL
SIG_ERR
- SIG_IGN</pre>
+ SIG_IGN
+</pre>
which expand to constant expressions with distinct values that have type compatible with
the second argument to, and the return value of, the signal function, and whose values
compare unequal to the address of any declarable function; and the following, which
expand to positive integer constant expressions with type int and distinct values that are
the signal numbers, each corresponding to the specified condition:
-<p><!--para 4 -->
<pre>
SIGABRT abnormal termination, such as is initiated by the abort function
SIGFPE an erroneous arithmetic operation, such as zero divide or an operation
SIGILL detection of an invalid function image, such as an invalid instruction
SIGINT receipt of an interactive attention signal
SIGSEGV an invalid access to storage
- SIGTERM a termination request sent to the program</pre>
+ SIGTERM a termination request sent to the program
+</pre>
+<p><!--para 4 -->
An implementation need not generate any of these signals, except as a result of explicit
calls to the raise function. Additional signals and pointers to undeclarable functions,
with macro definitions beginning, respectively, with the letters SIG and an uppercase
and termination.
</small>
-<a name="7.14.1" href="#7.14.1"><h4>7.14.1 Specify signal handling</h4></a>
+<h4><a name="7.14.1" href="#7.14.1">7.14.1 Specify signal handling</a></h4>
-<a name="7.14.1.1" href="#7.14.1.1"><h5>7.14.1.1 The signal function</h5></a>
+<h5><a name="7.14.1.1" href="#7.14.1.1">7.14.1.1 The signal function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.14"><signal.h></a>
- void (*signal(int sig, void (*func)(int)))(int);</pre>
+ void (*signal(int sig, void (*func)(int)))(int);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The signal function chooses one of three ways in which receipt of the signal number
<p><!--para 6 -->
At program startup, the equivalent of
<pre>
- signal(sig, SIG_IGN);</pre>
+ signal(sig, SIG_IGN);
+</pre>
may be executed for some signals selected in an implementation-defined manner; the
equivalent of
<pre>
- signal(sig, SIG_DFL);</pre>
+ signal(sig, SIG_DFL);
+</pre>
is executed for all other signals defined by the implementation.
<p><!--para 7 -->
The implementation shall behave as if no library function calls the signal function.
<p><small><a name="note249" href="#note249">249)</a> If any signal is generated by an asynchronous signal handler, the behavior is undefined.
</small>
-<a name="7.14.2" href="#7.14.2"><h4>7.14.2 Send signal</h4></a>
+<h4><a name="7.14.2" href="#7.14.2">7.14.2 Send signal</a></h4>
-<a name="7.14.2.1" href="#7.14.2.1"><h5>7.14.2.1 The raise function</h5></a>
+<h5><a name="7.14.2.1" href="#7.14.2.1">7.14.2.1 The raise function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.14"><signal.h></a>
- int raise(int sig);</pre>
+ int raise(int sig);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The raise function carries out the actions described in <a href="#7.14.1.1">7.14.1.1</a> for the signal sig. If a
The raise function returns zero if successful, nonzero if unsuccessful.
<!--page 285 -->
-<a name="7.15" href="#7.15"><h3>7.15 Alignment <stdalign.h></h3></a>
+<h3><a name="7.15" href="#7.15">7.15 Alignment <stdalign.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.15"><stdalign.h></a> defines two macros.
<p><!--para 2 -->
The macro
<pre>
- alignas</pre>
+ alignas
+</pre>
expands to _Alignas.
<p><!--para 3 -->
The remaining macro is suitable for use in #if preprocessing directives. It is
<pre>
- __alignas_is_defined</pre>
+ __alignas_is_defined
+</pre>
which expands to the integer constant 1.
<!--page 286 -->
-<a name="7.16" href="#7.16"><h3>7.16 Variable arguments <stdarg.h></h3></a>
+<h3><a name="7.16" href="#7.16">7.16 Variable arguments <stdarg.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.16"><stdarg.h></a> declares a type and defines four macros, for advancing
through a list of arguments whose number and types are not known to the called function
<p><!--para 3 -->
The type declared is
<pre>
- va_list</pre>
+ va_list
+</pre>
which is a complete object type suitable for holding information needed by the macros
va_start, va_arg, va_end, and va_copy. If access to the varying arguments is
desired, the called function shall declare an object (generally referred to as ap in this
case the original function may make further use of the original list after the other function returns.
</small>
-<a name="7.16.1" href="#7.16.1"><h4>7.16.1 Variable argument list access macros</h4></a>
+<h4><a name="7.16.1" href="#7.16.1">7.16.1 Variable argument list access macros</a></h4>
<p><!--para 1 -->
The va_start and va_arg macros described in this subclause shall be implemented
as macros, not functions. It is unspecified whether va_copy and va_end are macros or
shall be matched by a corresponding invocation of the va_end macro in the same
function.
-<a name="7.16.1.1" href="#7.16.1.1"><h5>7.16.1.1 The va_arg macro</h5></a>
+<h5><a name="7.16.1.1" href="#7.16.1.1">7.16.1.1 The va_arg macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
- type va_arg(va_list ap, type);</pre>
+ type va_arg(va_list ap, type);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The va_arg macro expands to an expression that has the specified type and the value of
value of the argument after that specified by parmN . Successive invocations return the
values of the remaining arguments in succession.
-<a name="7.16.1.2" href="#7.16.1.2"><h5>7.16.1.2 The va_copy macro</h5></a>
+<h5><a name="7.16.1.2" href="#7.16.1.2">7.16.1.2 The va_copy macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
- void va_copy(va_list dest, va_list src);</pre>
+ void va_copy(va_list dest, va_list src);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The va_copy macro initializes dest as a copy of src, as if the va_start macro had
<p><!--para 3 -->
The va_copy macro returns no value.
-<a name="7.16.1.3" href="#7.16.1.3"><h5>7.16.1.3 The va_end macro</h5></a>
+<h5><a name="7.16.1.3" href="#7.16.1.3">7.16.1.3 The va_end macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
- void va_end(va_list ap);</pre>
+ void va_end(va_list ap);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The va_end macro facilitates a normal return from the function whose variable
<p><!--para 3 -->
The va_end macro returns no value.
-<a name="7.16.1.4" href="#7.16.1.4"><h5>7.16.1.4 The va_start macro</h5></a>
+<h5><a name="7.16.1.4" href="#7.16.1.4">7.16.1.4 The va_start macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
- void va_start(va_list ap, parmN);</pre>
+ void va_start(va_list ap, parmN);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The va_start macro shall be invoked before any access to the unnamed arguments.
array[ptr_no++] = va_arg(ap, char *);
va_end(ap);
f2(n_ptrs, array);
- }</pre>
+ }
+</pre>
Each call to f1 is required to have visible the definition of the function or a declaration such as
<pre>
- void f1(int, ...);</pre>
+ void f1(int, ...);
+</pre>
<p><!--para 7 -->
EXAMPLE 2 The function f3 is similar, but saves the status of the variable argument list after the
array[ptr_no++] = va_arg(ap_save, char *);
va_end(ap_save);
f4(n_ptrs, array);
- }</pre>
+ }
+</pre>
-<a name="7.17" href="#7.17"><h3>7.17 Atomics <stdatomic.h></h3></a>
+<h3><a name="7.17" href="#7.17">7.17 Atomics <stdatomic.h></a></h3>
-<a name="7.17.1" href="#7.17.1"><h4>7.17.1 Introduction</h4></a>
+<h4><a name="7.17.1" href="#7.17.1">7.17.1 Introduction</a></h4>
<p><!--para 1 -->
The header <a href="#7.17"><stdatomic.h></a> defines several macros and declares several types and
functions for performing atomic operations on data shared between threads.
ATOMIC_INT_LOCK_FREE
ATOMIC_LONG_LOCK_FREE
ATOMIC_LLONG_LOCK_FREE
- ATOMIC_ADDRESS_LOCK_FREE</pre>
+ ATOMIC_ADDRESS_LOCK_FREE
+</pre>
which indicate the lock-free property of the corresponding atomic types (both signed and
unsigned); and
<pre>
- ATOMIC_FLAG_INIT</pre>
+ ATOMIC_FLAG_INIT
+</pre>
which expands to an initializer for an object of type atomic_flag.
<p><!--para 4 -->
The types include
<pre>
- memory_order</pre>
+ memory_order
+</pre>
which is an enumerated type whose enumerators identify memory ordering constraints;
<pre>
- atomic_flag</pre>
+ atomic_flag
+</pre>
which is a structure type representing a lock-free, primitive atomic flag;
<pre>
- atomic_bool</pre>
+ atomic_bool
+</pre>
which is a structure type representing the atomic analog of the type _Bool;
<pre>
- atomic_address</pre>
+ atomic_address
+</pre>
which is a structure type representing the atomic analog of a pointer type; and several
atomic analogs of integer types.
<p><!--para 5 -->
operations to volatile objects.
-<a name="7.17.2" href="#7.17.2"><h4>7.17.2 Initialization</h4></a>
+<h4><a name="7.17.2" href="#7.17.2">7.17.2 Initialization</a></h4>
-<a name="7.17.2.1" href="#7.17.2.1"><h5>7.17.2.1 The ATOMIC_VAR_INIT macro</h5></a>
+<h5><a name="7.17.2.1" href="#7.17.2.1">7.17.2.1 The ATOMIC_VAR_INIT macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
- #define ATOMIC_VAR_INIT(C value)</pre>
+ #define ATOMIC_VAR_INIT(C value)
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ATOMIC_VAR_INIT macro expands to a token sequence suitable for initializing an
<p><!--para 4 -->
EXAMPLE
<pre>
- atomic_int guide = ATOMIC_VAR_INIT(42);</pre>
+ atomic_int guide = ATOMIC_VAR_INIT(42);
+</pre>
-<a name="7.17.2.2" href="#7.17.2.2"><h5>7.17.2.2 The atomic_init generic function</h5></a>
+<h5><a name="7.17.2.2" href="#7.17.2.2">7.17.2.2 The atomic_init generic function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
- void atomic_init(volatile A *obj, C value);</pre>
+ void atomic_init(volatile A *obj, C value);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The atomic_init generic function initializes the atomic object pointed to by obj to
EXAMPLE
<pre>
atomic_int guide;
- atomic_init(&guide, 42);</pre>
+ atomic_init(&guide, 42);
+</pre>
-<a name="7.17.3" href="#7.17.3"><h4>7.17.3 Order and consistency</h4></a>
+<h4><a name="7.17.3" href="#7.17.3">7.17.3 Order and consistency</a></h4>
<p><!--para 1 -->
The enumerated type memory_order specifies the detailed regular (non-atomic)
memory synchronization operations as defined in <a href="#5.1.2.4">5.1.2.4</a> and may provide for operation
ordering. Its enumeration constants are as follows:
-<p><!--para 2 -->
<pre>
memory_order_relaxed
memory_order_consume
memory_order_acquire
memory_order_release
memory_order_acq_rel
- memory_order_seq_cst</pre>
+ memory_order_seq_cst
+</pre>
+<p><!--para 2 -->
For memory_order_relaxed, no operation orders memory.
<p><!--para 3 -->
For memory_order_release, memory_order_acq_rel, and
<pre>
// Thread 1:
r1 = atomic_load_explicit(&y, memory_order_relaxed);
- atomic_store_explicit(&x, r1, memory_order_relaxed);</pre>
+ atomic_store_explicit(&x, r1, memory_order_relaxed);
+</pre>
<pre>
// Thread 2:
r2 = atomic_load_explicit(&x, memory_order_relaxed);
- atomic_store_explicit(&y, 42, memory_order_relaxed);</pre>
+ atomic_store_explicit(&y, 42, memory_order_relaxed);
+</pre>
is allowed to produce r1 == 42 && r2 == 42. The sequence of evaluations justifying this consists of:
atomic_store_explicit(&y, 42, memory_order_relaxed);
r1 = atomic_load_explicit(&y, memory_order_relaxed);
atomic_store_explicit(&x, r1, memory_order_relaxed);
- r2 = atomic_load_explicit(&x, memory_order_relaxed);</pre>
+ r2 = atomic_load_explicit(&x, memory_order_relaxed);
+</pre>
On the other hand,
<pre>
// Thread 1:
r1 = atomic_load_explicit(&y, memory_order_relaxed);
- atomic_store_explicit(&x, r1, memory_order_relaxed);</pre>
+ atomic_store_explicit(&x, r1, memory_order_relaxed);
+</pre>
<pre>
// Thread 2:
r2 = atomic_load_explicit(&x, memory_order_relaxed);
- atomic_store_explicit(&y, r2, memory_order_relaxed);</pre>
+ atomic_store_explicit(&y, r2, memory_order_relaxed);
+</pre>
is not allowed to produce r1 == 42 && r2 = 42, since there is no sequence of evaluations that results
in the computation of 42. In the absence of ''relaxed'' operations and read-modify-write operations with
weaker than memory_order_acq_rel ordering, the second requirement has no impact.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 15 -->
The requirements do not forbid r1 == 42 && r2 == 42 in the following example,
with x and y initially zero:
// Thread 1:
r1 = atomic_load_explicit(&x, memory_order_relaxed);
if (r1 == 42)
- atomic_store_explicit(&y, r1, memory_order_relaxed);</pre>
+ atomic_store_explicit(&y, r1, memory_order_relaxed);
+</pre>
<pre>
// Thread 2:
r2 = atomic_load_explicit(&y, memory_order_relaxed);
if (r2 == 42)
- atomic_store_explicit(&x, 42, memory_order_relaxed);</pre>
+ atomic_store_explicit(&x, 42, memory_order_relaxed);
+</pre>
However, this is not useful behavior, and implementations should not allow it.
<p><!--para 16 -->
Implementations should make atomic stores visible to atomic loads within a reasonable
<p><small><a name="note251" href="#note251">251)</a> Among other implications, atomic variables shall not decay.
</small>
-<a name="7.17.3.1" href="#7.17.3.1"><h5>7.17.3.1 The kill_dependency macro</h5></a>
+<h5><a name="7.17.3.1" href="#7.17.3.1">7.17.3.1 The kill_dependency macro</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
- type kill_dependency(type y);</pre>
+ type kill_dependency(type y);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The kill_dependency macro terminates a dependency chain; the argument does not
<p><!--para 3 -->
The kill_dependency macro returns the value of y.
-<a name="7.17.4" href="#7.17.4"><h4>7.17.4 Fences</h4></a>
+<h4><a name="7.17.4" href="#7.17.4">7.17.4 Fences</a></h4>
<p><!--para 1 -->
This subclause introduces synchronization primitives called fences. Fences can have
acquire semantics, release semantics, or both. A fence with acquire semantics is called
sequenced before B and reads the value written by A or a value written by any side effect
in the release sequence headed by A.
-<a name="7.17.4.1" href="#7.17.4.1"><h5>7.17.4.1 The atomic_thread_fence function</h5></a>
+<h5><a name="7.17.4.1" href="#7.17.4.1">7.17.4.1 The atomic_thread_fence function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
- void atomic_thread_fence(memory_order order);</pre>
+ void atomic_thread_fence(memory_order order);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
Depending on the value of order, this operation:
<p><!--para 3 -->
The atomic_thread_fence function returns no value.
-<a name="7.17.4.2" href="#7.17.4.2"><h5>7.17.4.2 The atomic_signal_fence function</h5></a>
+<h5><a name="7.17.4.2" href="#7.17.4.2">7.17.4.2 The atomic_signal_fence function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
- void atomic_signal_fence(memory_order order);</pre>
+ void atomic_signal_fence(memory_order order);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
Equivalent to atomic_thread_fence(order), except that ''synchronizes with''
<p><!--para 5 -->
The atomic_signal_fence function returns no value.
-<a name="7.17.5" href="#7.17.5"><h4>7.17.5 Lock-free property</h4></a>
+<h4><a name="7.17.5" href="#7.17.5">7.17.5 Lock-free property</a></h4>
<p><!--para 1 -->
The atomic lock-free macros indicate the lock-free property of integer and address atomic
types. A value of 0 indicates that the type is never lock-free; a value of 1 indicates that
process more than once and memory shared between two processes.
-<a name="7.17.5.1" href="#7.17.5.1"><h5>7.17.5.1 The atomic_is_lock_free generic function</h5></a>
+<h5><a name="7.17.5.1" href="#7.17.5.1">7.17.5.1 The atomic_is_lock_free generic function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
- _Bool atomic_is_lock_free(atomic_type const volatile *obj);</pre>
+ _Bool atomic_is_lock_free(atomic_type const volatile *obj);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The atomic_is_lock_free generic function indicates whether or not the object
<!--page 297 -->
inferred from the result of a lock-free query on another object.
-<a name="7.17.6" href="#7.17.6"><h4>7.17.6 Atomic integer and address types</h4></a>
+<h4><a name="7.17.6" href="#7.17.6">7.17.6 Atomic integer and address types</a></h4>
<p><!--para 1 -->
For each line in the following table, the atomic type name is declared as the
corresponding direct type.
<!--page 298 -->
-<p><!--para 2 -->
<pre>
Atomic type name Direct type
atomic_char _Atomic char
atomic_size_t _Atomic size_t
atomic_ptrdiff_t _Atomic ptrdiff_t
atomic_intmax_t _Atomic intmax_t
- atomic_uintmax_t _Atomic uintmax_t</pre>
+ atomic_uintmax_t _Atomic uintmax_t
+</pre>
+<p><!--para 2 -->
The semantics of the operations on these types are defined in <a href="#7.17.7">7.17.7</a>.
<p><!--para 3 -->
The atomic_bool type provides an atomic boolean.
to port existing code.
-<a name="7.17.7" href="#7.17.7"><h4>7.17.7 Operations on atomic types</h4></a>
+<h4><a name="7.17.7" href="#7.17.7">7.17.7 Operations on atomic types</a></h4>
<p><!--para 1 -->
There are only a few kinds of operations on atomic types, though there are many
instances of those kinds. This subclause specifies each general kind.
-<a name="7.17.7.1" href="#7.17.7.1"><h5>7.17.7.1 The atomic_store generic functions</h5></a>
+<h5><a name="7.17.7.1" href="#7.17.7.1">7.17.7.1 The atomic_store generic functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
void atomic_store(volatile A *object, C desired);
void atomic_store_explicit(volatile A *object,
- C desired, memory_order order);</pre>
+ C desired, memory_order order);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The order argument shall not be memory_order_acquire,
<p><!--para 3 -->
The atomic_store generic functions return no value.
-<a name="7.17.7.2" href="#7.17.7.2"><h5>7.17.7.2 The atomic_load generic functions</h5></a>
+<h5><a name="7.17.7.2" href="#7.17.7.2">7.17.7.2 The atomic_load generic functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
C atomic_load(volatile A *object);
C atomic_load_explicit(volatile A *object,
- memory_order order);</pre>
+ memory_order order);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The order argument shall not be memory_order_release nor
Atomically returns the value pointed to by object.
<!--page 300 -->
-<a name="7.17.7.3" href="#7.17.7.3"><h5>7.17.7.3 The atomic_exchange generic functions</h5></a>
+<h5><a name="7.17.7.3" href="#7.17.7.3">7.17.7.3 The atomic_exchange generic functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
C atomic_exchange(volatile A *object, C desired);
C atomic_exchange_explicit(volatile A *object,
- C desired, memory_order order);</pre>
+ C desired, memory_order order);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
Atomically replace the value pointed to by object with desired. Memory is affected
<p><!--para 3 -->
Atomically returns the value pointed to by object immediately before the effects.
-<a name="7.17.7.4" href="#7.17.7.4"><h5>7.17.7.4 The atomic_compare_exchange generic functions</h5></a>
+<h5><a name="7.17.7.4" href="#7.17.7.4">7.17.7.4 The atomic_compare_exchange generic functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
C *expected, C desired);
_Bool atomic_compare_exchange_weak_explicit(
volatile A *object, C *expected, C desired,
- memory_order success, memory_order failure);</pre>
+ memory_order success, memory_order failure);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The failure argument shall not be memory_order_release nor
if (*object == *expected)
*object = desired;
else
- *expected = *object;</pre>
+ *expected = *object;
+</pre>
<p><!--para 4 -->
The weak compare-and-exchange operations may fail spuriously, that is, return zero
exp = atomic_load(&cur);
do {
des = function(exp);
- } while (!atomic_compare_exchange_weak(&cur, &exp, des));</pre>
+ } while (!atomic_compare_exchange_weak(&cur, &exp, des));
+</pre>
When a compare-and-exchange is in a loop, the weak version will yield better performance on some
platforms. When a weak compare-and-exchange would require a loop and a strong one would not, the
strong one is preferable.
<p><!--para 7 -->
The result of the comparison.
-<a name="7.17.7.5" href="#7.17.7.5"><h5>7.17.7.5 The atomic_fetch and modify generic functions</h5></a>
+<h5><a name="7.17.7.5" href="#7.17.7.5">7.17.7.5 The atomic_fetch and modify generic functions</a></h5>
<p><!--para 1 -->
The following operations perform arithmetic and bitwise computations. All of these
operations are applicable to an object of any atomic integer type. Only addition and
#include <a href="#7.17"><stdatomic.h></a>
C atomic_fetch_key(volatile A *object, M operand);
C atomic_fetch_key_explicit(volatile A *object,
- M operand, memory_order order);</pre>
+ M operand, memory_order order);
+</pre>
<h6>Description</h6>
<p><!--para 3 -->
Atomically replaces the value pointed to by object with the result of the computation
atomic_fetch and modify generic functions is the previous value of the atomic object.
-<a name="7.17.8" href="#7.17.8"><h4>7.17.8 Atomic flag type and operations</h4></a>
+<h4><a name="7.17.8" href="#7.17.8">7.17.8 Atomic flag type and operations</a></h4>
<p><!--para 1 -->
The atomic_flag type provides the classic test-and-set functionality. It has two
states, set and clear.
<p><!--para 5 -->
EXAMPLE
<pre>
- atomic_flag guard = ATOMIC_FLAG_INIT;</pre>
+ atomic_flag guard = ATOMIC_FLAG_INIT;
+</pre>
-<a name="7.17.8.1" href="#7.17.8.1"><h5>7.17.8.1 The atomic_flag_test_and_set functions</h5></a>
+<h5><a name="7.17.8.1" href="#7.17.8.1">7.17.8.1 The atomic_flag_test_and_set functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
bool atomic_flag_test_and_set(
volatile atomic_flag *object);
bool atomic_flag_test_and_set_explicit(
- volatile atomic_flag *object, memory_order order);</pre>
+ volatile atomic_flag *object, memory_order order);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
Atomically sets the value pointed to by object to true. Memory is affected according
<p><!--para 3 -->
Atomically, the value of the object immediately before the effects.
-<a name="7.17.8.2" href="#7.17.8.2"><h5>7.17.8.2 The atomic_flag_clear functions</h5></a>
+<h5><a name="7.17.8.2" href="#7.17.8.2">7.17.8.2 The atomic_flag_clear functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.17"><stdatomic.h></a>
void atomic_flag_clear(volatile atomic_flag *object);
void atomic_flag_clear_explicit(
- volatile atomic_flag *object, memory_order order);</pre>
+ volatile atomic_flag *object, memory_order order);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The order argument shall not be memory_order_acquire nor
The atomic_flag_clear functions return no value.
<!--page 304 -->
-<a name="7.18" href="#7.18"><h3>7.18 Boolean type and values <stdbool.h></h3></a>
+<h3><a name="7.18" href="#7.18">7.18 Boolean type and values <stdbool.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.18"><stdbool.h></a> defines four macros.
<p><!--para 2 -->
The macro
<pre>
- bool</pre>
+ bool
+</pre>
expands to _Bool.
<p><!--para 3 -->
The remaining three macros are suitable for use in #if preprocessing directives. They
are
<pre>
- true</pre>
+ true
+</pre>
which expands to the integer constant 1,
<pre>
- false</pre>
+ false
+</pre>
which expands to the integer constant 0, and
<pre>
- __bool_true_false_are_defined</pre>
+ __bool_true_false_are_defined
+</pre>
which expands to the integer constant 1.
<p><!--para 4 -->
Notwithstanding the provisions of <a href="#7.1.3">7.1.3</a>, a program may undefine and perhaps then
<p><small><a name="note252" href="#note252">252)</a> See ''future library directions'' (<a href="#7.30.7">7.30.7</a>).
</small>
-<a name="7.19" href="#7.19"><h3>7.19 Common definitions <stddef.h></h3></a>
+<h3><a name="7.19" href="#7.19">7.19 Common definitions <stddef.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.19"><stddef.h></a> defines the following macros and declares the following types.
Some are also defined in other headers, as noted in their respective subclauses.
<p><!--para 2 -->
The types are
<pre>
- ptrdiff_t</pre>
+ ptrdiff_t
+</pre>
which is the signed integer type of the result of subtracting two pointers;
<pre>
- size_t</pre>
+ size_t
+</pre>
which is the unsigned integer type of the result of the sizeof operator;
<pre>
- max_align_t</pre>
+ max_align_t
+</pre>
which is an object type whose alignment is as great as is supported by the implementation
in all contexts; and
<pre>
- wchar_t</pre>
+ wchar_t
+</pre>
which is an integer type whose range of values can represent distinct codes for all
members of the largest extended character set specified among the supported locales; the
null character shall have the code value zero. Each member of the basic character set
<p><!--para 3 -->
The macros are
<pre>
- NULL</pre>
+ NULL
+</pre>
which expands to an implementation-defined null pointer constant; and
<pre>
- offsetof(type, member-designator)</pre>
+ offsetof(type, member-designator)
+</pre>
which expands to an integer constant expression that has type size_t, the value of
which is the offset in bytes, to the structure member (designated by member-designator),
from the beginning of its structure (designated by type). The type and member designator
shall be such that given
<pre>
- static type t;</pre>
+ static type t;
+</pre>
then the expression &(t.member-designator) evaluates to an address constant. (If the
specified member is a bit-field, the behavior is undefined.)
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 4 -->
The types used for size_t and ptrdiff_t should not have an integer conversion rank
greater than that of signed long int unless the implementation supports objects
<p><b> Forward references</b>: localization (<a href="#7.11">7.11</a>).
<!--page 307 -->
-<a name="7.20" href="#7.20"><h3>7.20 Integer types <stdint.h></h3></a>
+<h3><a name="7.20" href="#7.20">7.20 Integer types <stdint.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.20"><stdint.h></a> declares sets of integer types having specified widths, and
defines corresponding sets of macros.<sup><a href="#note253"><b>253)</b></a></sup> It also defines macros that specify limits of
<p><small><a name="note254" href="#note254">254)</a> Some of these types may denote implementation-defined extended integer types.
</small>
-<a name="7.20.1" href="#7.20.1"><h4>7.20.1 Integer types</h4></a>
+<h4><a name="7.20.1" href="#7.20.1">7.20.1 Integer types</a></h4>
<p><!--para 1 -->
When typedef names differing only in the absence or presence of the initial u are defined,
they shall denote corresponding signed and unsigned types as described in <a href="#6.2.5">6.2.5</a>; an
<!--page 308 -->
-<a name="7.20.1.1" href="#7.20.1.1"><h5>7.20.1.1 Exact-width integer types</h5></a>
+<h5><a name="7.20.1.1" href="#7.20.1.1">7.20.1.1 Exact-width integer types</a></h5>
<p><!--para 1 -->
The typedef name intN_t designates a signed integer type with width N , no padding
bits, and a two's complement representation. Thus, int8_t denotes such a signed
widths of 8, 16, 32, or 64 bits, no padding bits, and (for the signed types) that have a
two's complement representation, it shall define the corresponding typedef names.
-<a name="7.20.1.2" href="#7.20.1.2"><h5>7.20.1.2 Minimum-width integer types</h5></a>
+<h5><a name="7.20.1.2" href="#7.20.1.2">7.20.1.2 Minimum-width integer types</a></h5>
<p><!--para 1 -->
The typedef name int_leastN_t designates a signed integer type with a width of at
least N , such that no signed integer type with lesser size has at least the specified width.
int_least8_t uint_least8_t
int_least16_t uint_least16_t
int_least32_t uint_least32_t
- int_least64_t uint_least64_t</pre>
+ int_least64_t uint_least64_t
+</pre>
All other types of this form are optional.
-<a name="7.20.1.3" href="#7.20.1.3"><h5>7.20.1.3 Fastest minimum-width integer types</h5></a>
+<h5><a name="7.20.1.3" href="#7.20.1.3">7.20.1.3 Fastest minimum-width integer types</a></h5>
<p><!--para 1 -->
Each of the following types designates an integer type that is usually fastest<sup><a href="#note255"><b>255)</b></a></sup> to operate
with among all integer types that have at least the specified width.
int_fast8_t uint_fast8_t
int_fast16_t uint_fast16_t
int_fast32_t uint_fast32_t
- int_fast64_t uint_fast64_t</pre>
+ int_fast64_t uint_fast64_t
+</pre>
All other types of this form are optional.
<h6>footnotes</h6>
signedness and width requirements.
</small>
-<a name="7.20.1.4" href="#7.20.1.4"><h5>7.20.1.4 Integer types capable of holding object pointers</h5></a>
+<h5><a name="7.20.1.4" href="#7.20.1.4">7.20.1.4 Integer types capable of holding object pointers</a></h5>
<p><!--para 1 -->
The following type designates a signed integer type with the property that any valid
pointer to void can be converted to this type, then converted back to pointer to void,
and the result will compare equal to the original pointer:
<pre>
- intptr_t</pre>
+ intptr_t
+</pre>
The following type designates an unsigned integer type with the property that any valid
pointer to void can be converted to this type, then converted back to pointer to void,
and the result will compare equal to the original pointer:
<pre>
- uintptr_t</pre>
+ uintptr_t
+</pre>
These types are optional.
-<a name="7.20.1.5" href="#7.20.1.5"><h5>7.20.1.5 Greatest-width integer types</h5></a>
+<h5><a name="7.20.1.5" href="#7.20.1.5">7.20.1.5 Greatest-width integer types</a></h5>
<p><!--para 1 -->
The following type designates a signed integer type capable of representing any value of
any signed integer type:
<pre>
- intmax_t</pre>
+ intmax_t
+</pre>
The following type designates an unsigned integer type capable of representing any value
of any unsigned integer type:
<pre>
- uintmax_t</pre>
+ uintmax_t
+</pre>
These types are required.
-<a name="7.20.2" href="#7.20.2"><h4>7.20.2 Limits of specified-width integer types</h4></a>
+<h4><a name="7.20.2" href="#7.20.2">7.20.2 Limits of specified-width integer types</a></h4>
<p><!--para 1 -->
The following object-like macros specify the minimum and maximum limits of the types *
declared in <a href="#7.20"><stdint.h></a>. Each macro name corresponds to a similar type name in
except where stated to be exactly the given value.
<!--page 310 -->
-<a name="7.20.2.1" href="#7.20.2.1"><h5>7.20.2.1 Limits of exact-width integer types</h5></a>
+<h5><a name="7.20.2.1" href="#7.20.2.1">7.20.2.1 Limits of exact-width integer types</a></h5>
<p><!--para 1 -->
<ul>
<li> minimum values of exact-width signed integer types
<pre>
- INTN_MIN exactly -(2 N -1 )</pre>
+ INTN_MIN exactly -(2 N -1 )
+</pre>
<li> maximum values of exact-width signed integer types
<pre>
- INTN_MAX exactly 2 N -1 - 1</pre>
+ INTN_MAX exactly 2 N -1 - 1
+</pre>
<li> maximum values of exact-width unsigned integer types
UINTN_MAX exactly 2 N - 1
</ul>
-<a name="7.20.2.2" href="#7.20.2.2"><h5>7.20.2.2 Limits of minimum-width integer types</h5></a>
+<h5><a name="7.20.2.2" href="#7.20.2.2">7.20.2.2 Limits of minimum-width integer types</a></h5>
<p><!--para 1 -->
<ul>
<li> minimum values of minimum-width signed integer types
<pre>
- INT_LEASTN_MIN -(2 N -1 - 1)</pre>
+ INT_LEASTN_MIN -(2 N -1 - 1)
+</pre>
<li> maximum values of minimum-width signed integer types
<pre>
- INT_LEASTN_MAX 2 N -1 - 1</pre>
+ INT_LEASTN_MAX 2 N -1 - 1
+</pre>
<li> maximum values of minimum-width unsigned integer types
UINT_LEASTN_MAX 2N - 1
</ul>
-<a name="7.20.2.3" href="#7.20.2.3"><h5>7.20.2.3 Limits of fastest minimum-width integer types</h5></a>
+<h5><a name="7.20.2.3" href="#7.20.2.3">7.20.2.3 Limits of fastest minimum-width integer types</a></h5>
<p><!--para 1 -->
<ul>
<li> minimum values of fastest minimum-width signed integer types
<pre>
- INT_FASTN_MIN -(2 N -1 - 1)</pre>
+ INT_FASTN_MIN -(2 N -1 - 1)
+</pre>
<li> maximum values of fastest minimum-width signed integer types
INT_FASTN_MAX 2 N -1 - 1
<li> maximum values of fastest minimum-width unsigned integer types
UINT_FASTN_MAX 2N - 1
</ul>
-<a name="7.20.2.4" href="#7.20.2.4"><h5>7.20.2.4 Limits of integer types capable of holding object pointers</h5></a>
+<h5><a name="7.20.2.4" href="#7.20.2.4">7.20.2.4 Limits of integer types capable of holding object pointers</a></h5>
<p><!--para 1 -->
<ul>
<li> minimum value of pointer-holding signed integer type
<pre>
- INTPTR_MIN -(215 - 1)</pre>
+ INTPTR_MIN -(215 - 1)
+</pre>
<li> maximum value of pointer-holding signed integer type
INTPTR_MAX 215 - 1
<li> maximum value of pointer-holding unsigned integer type
<!--page 311 -->
</ul>
-<a name="7.20.2.5" href="#7.20.2.5"><h5>7.20.2.5 Limits of greatest-width integer types</h5></a>
+<h5><a name="7.20.2.5" href="#7.20.2.5">7.20.2.5 Limits of greatest-width integer types</a></h5>
<p><!--para 1 -->
<ul>
<li> minimum value of greatest-width signed integer type
UINTMAX_MAX 264 - 1
</ul>
-<a name="7.20.3" href="#7.20.3"><h4>7.20.3 Limits of other integer types</h4></a>
+<h4><a name="7.20.3" href="#7.20.3">7.20.3 Limits of other integer types</a></h4>
<p><!--para 1 -->
The following object-like macros specify the minimum and maximum limits of integer *
types corresponding to types defined in other standard headers.
character set.
</small>
-<a name="7.20.4" href="#7.20.4"><h4>7.20.4 Macros for integer constants</h4></a>
+<h4><a name="7.20.4" href="#7.20.4">7.20.4 Macros for integer constants</a></h4>
<p><!--para 1 -->
The following function-like macros expand to integer constants suitable for initializing *
objects that have integer types corresponding to types defined in <a href="#7.20"><stdint.h></a>. Each
the same type as would an expression of the corresponding type converted according to
the integer promotions. The value of the expression shall be that of the argument.
-<a name="7.20.4.1" href="#7.20.4.1"><h5>7.20.4.1 Macros for minimum-width integer constants</h5></a>
+<h5><a name="7.20.4.1" href="#7.20.4.1">7.20.4.1 Macros for minimum-width integer constants</a></h5>
<p><!--para 1 -->
The macro INTN_C(value) shall expand to an integer constant expression
corresponding to the type int_leastN_t. The macro UINTN_C(value) shall expand
<!--page 313 -->
-<a name="7.20.4.2" href="#7.20.4.2"><h5>7.20.4.2 Macros for greatest-width integer constants</h5></a>
+<h5><a name="7.20.4.2" href="#7.20.4.2">7.20.4.2 Macros for greatest-width integer constants</a></h5>
<p><!--para 1 -->
The following macro expands to an integer constant expression having the value specified
by its argument and the type intmax_t:
<pre>
- INTMAX_C(value)</pre>
+ INTMAX_C(value)
+</pre>
The following macro expands to an integer constant expression having the value specified
by its argument and the type uintmax_t:
<!--page 314 -->
<pre>
- UINTMAX_C(value)</pre>
+ UINTMAX_C(value)
+</pre>
-<a name="7.21" href="#7.21"><h3>7.21 Input/output <stdio.h></h3></a>
+<h3><a name="7.21" href="#7.21">7.21 Input/output <stdio.h></a></h3>
-<a name="7.21.1" href="#7.21.1"><h4>7.21.1 Introduction</h4></a>
+<h4><a name="7.21.1" href="#7.21.1">7.21.1 Introduction</a></h4>
<p><!--para 1 -->
The header <a href="#7.21"><stdio.h></a> defines several macros, and declares three types and many
functions for performing input and output.
<p><!--para 2 -->
The types declared are size_t (described in <a href="#7.19">7.19</a>);
<pre>
- FILE</pre>
+ FILE
+</pre>
which is an object type capable of recording all the information needed to control a
stream, including its file position indicator, a pointer to its associated buffer (if any), an
error indicator that records whether a read/write error has occurred, and an end-of-file
indicator that records whether the end of the file has been reached; and
<pre>
- fpos_t</pre>
+ fpos_t
+</pre>
which is a complete object type other than an array type capable of recording all the
information needed to specify uniquely every position within a file.
<p><!--para 3 -->
<pre>
_IOFBF
_IOLBF
- _IONBF</pre>
+ _IONBF
+</pre>
which expand to integer constant expressions with distinct values, suitable for use as the
third argument to the setvbuf function;
<pre>
- BUFSIZ</pre>
+ BUFSIZ
+</pre>
which expands to an integer constant expression that is the size of the buffer used by the
setbuf function;
<pre>
- EOF</pre>
+ EOF
+</pre>
which expands to an integer constant expression, with type int and a negative value, that
is returned by several functions to indicate end-of-file, that is, no more input from a
stream;
<pre>
- FOPEN_MAX</pre>
+ FOPEN_MAX
+</pre>
which expands to an integer constant expression that is the minimum number of files that
the implementation guarantees can be open simultaneously;
<pre>
- FILENAME_MAX</pre>
+ FILENAME_MAX
+</pre>
which expands to an integer constant expression that is the size needed for an array of
char large enough to hold the longest file name string that the implementation
<!--page 315 -->
guarantees can be opened;<sup><a href="#note258"><b>258)</b></a></sup>
<pre>
- L_tmpnam</pre>
+ L_tmpnam
+</pre>
which expands to an integer constant expression that is the size needed for an array of
char large enough to hold a temporary file name string generated by the tmpnam
function;
<pre>
SEEK_CUR
SEEK_END
- SEEK_SET</pre>
+ SEEK_SET
+</pre>
which expand to integer constant expressions with distinct values, suitable for use as the
third argument to the fseek function;
<pre>
- TMP_MAX</pre>
+ TMP_MAX
+</pre>
which expands to an integer constant expression that is the minimum number of unique
file names that can be generated by the tmpnam function;
<pre>
stderr
stdin
- stdout</pre>
+ stdout
+</pre>
which are expressions of type ''pointer to FILE'' that point to the FILE objects
associated, respectively, with the standard error, input, and output streams.
<p><!--para 4 -->
all possible strings of length FILENAME_MAX cannot be expected to be opened successfully.
</small>
-<a name="7.21.2" href="#7.21.2"><h4>7.21.2 Streams</h4></a>
+<h4><a name="7.21.2" href="#7.21.2">7.21.2 Streams</a></h4>
<p><!--para 1 -->
Input and output, whether to or from physical devices such as terminals and tape drives,
or whether to or from files supported on structured storage devices, are mapped into
value of this mbstate_t object as part of the value of the fpos_t object. A later
successful call to fsetpos using the same stored fpos_t value restores the value of
the associated mbstate_t object as well as the position within the controlled stream.
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 7 -->
An implementation shall support text files with lines containing at least 254 characters,
including the terminating new-line character. The value of the macro BUFSIZ shall be at
<p><small><a name="note260" href="#note260">260)</a> The three predefined streams stdin, stdout, and stderr are unoriented at program startup.
</small>
-<a name="7.21.3" href="#7.21.3"><h4>7.21.3 Files</h4></a>
+<h4><a name="7.21.3" href="#7.21.3">7.21.3 Files</a></h4>
<p><!--para 1 -->
A stream is associated with an external file (which may be a physical device) by opening
a file, which may involve creating a new file. Creating an existing file causes its former
multibyte character. The wide character input/output functions and the byte input/output
functions store the value of the macro EILSEQ in errno if and only if an encoding error
occurs.
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 15 -->
The value of FOPEN_MAX shall be at least eight, including the three standard text
streams.
with state-dependent encoding that does not assuredly end in the initial shift state.
</small>
-<a name="7.21.4" href="#7.21.4"><h4>7.21.4 Operations on files</h4></a>
+<h4><a name="7.21.4" href="#7.21.4">7.21.4 Operations on files</a></h4>
-<a name="7.21.4.1" href="#7.21.4.1"><h5>7.21.4.1 The remove function</h5></a>
+<h5><a name="7.21.4.1" href="#7.21.4.1">7.21.4.1 The remove function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int remove(const char *filename);</pre>
+ int remove(const char *filename);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The remove function causes the file whose name is the string pointed to by filename
<p><!--para 3 -->
The remove function returns zero if the operation succeeds, nonzero if it fails.
-<a name="7.21.4.2" href="#7.21.4.2"><h5>7.21.4.2 The rename function</h5></a>
+<h5><a name="7.21.4.2" href="#7.21.4.2">7.21.4.2 The rename function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int rename(const char *old, const char *new);</pre>
+ int rename(const char *old, const char *new);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The rename function causes the file whose name is the string pointed to by old to be
or that it is necessary to copy its contents to effectuate its renaming.
</small>
-<a name="7.21.4.3" href="#7.21.4.3"><h5>7.21.4.3 The tmpfile function</h5></a>
+<h5><a name="7.21.4.3" href="#7.21.4.3">7.21.4.3 The tmpfile function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- FILE *tmpfile(void);</pre>
+ FILE *tmpfile(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tmpfile function creates a temporary binary file that is different from any other
existing file and that will automatically be removed when it is closed or at program
termination. If the program terminates abnormally, whether an open temporary file is
removed is implementation-defined. The file is opened for update with "wb+" mode.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 3 -->
It should be possible to open at least TMP_MAX temporary files during the lifetime of the
program (this limit may be shared with tmpnam) and there should be no limit on the
cannot be created, the tmpfile function returns a null pointer.
<p><b> Forward references</b>: the fopen function (<a href="#7.21.5.3">7.21.5.3</a>).
-<a name="7.21.4.4" href="#7.21.4.4"><h5>7.21.4.4 The tmpnam function</h5></a>
+<h5><a name="7.21.4.4" href="#7.21.4.4">7.21.4.4 The tmpnam function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- char *tmpnam(char *s);</pre>
+ char *tmpnam(char *s);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tmpnam function generates a string that is a valid file name and that is not the same
function may modify the same object). If the argument is not a null pointer, it is assumed
to point to an array of at least L_tmpnam chars; the tmpnam function writes its result
in that array and returns the argument as its value.
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 6 -->
The value of the macro TMP_MAX shall be at least 25.
is ended, and before program termination.
</small>
-<a name="7.21.5" href="#7.21.5"><h4>7.21.5 File access functions</h4></a>
+<h4><a name="7.21.5" href="#7.21.5">7.21.5 File access functions</a></h4>
-<a name="7.21.5.1" href="#7.21.5.1"><h5>7.21.5.1 The fclose function</h5></a>
+<h5><a name="7.21.5.1" href="#7.21.5.1">7.21.5.1 The fclose function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int fclose(FILE *stream);</pre>
+ int fclose(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A successful call to the fclose function causes the stream pointed to by stream to be
errors were detected.
<!--page 323 -->
-<a name="7.21.5.2" href="#7.21.5.2"><h5>7.21.5.2 The fflush function</h5></a>
+<h5><a name="7.21.5.2" href="#7.21.5.2">7.21.5.2 The fflush function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int fflush(FILE *stream);</pre>
+ int fflush(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If stream points to an output stream or an update stream in which the most recent
error occurs, otherwise it returns zero.
<p><b> Forward references</b>: the fopen function (<a href="#7.21.5.3">7.21.5.3</a>).
-<a name="7.21.5.3" href="#7.21.5.3"><h5>7.21.5.3 The fopen function</h5></a>
+<h5><a name="7.21.5.3" href="#7.21.5.3">7.21.5.3 The fopen function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
FILE *fopen(const char * restrict filename,
- const char * restrict mode);</pre>
+ const char * restrict mode);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fopen function opens the file whose name is the string pointed to by filename,
conform to the properties in <a href="#7.21.2">7.21.2</a>).
</small>
-<a name="7.21.5.4" href="#7.21.5.4"><h5>7.21.5.4 The freopen function</h5></a>
+<h5><a name="7.21.5.4" href="#7.21.5.4">7.21.5.4 The freopen function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
FILE *freopen(const char * restrict filename,
const char * restrict mode,
- FILE * restrict stream);</pre>
+ FILE * restrict stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The freopen function opens the file whose name is the string pointed to by filename
returned by the fopen function may be assigned.
</small>
-<a name="7.21.5.5" href="#7.21.5.5"><h5>7.21.5.5 The setbuf function</h5></a>
+<h5><a name="7.21.5.5" href="#7.21.5.5">7.21.5.5 The setbuf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
void setbuf(FILE * restrict stream,
- char * restrict buf);</pre>
+ char * restrict buf);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
Except that it returns no value, the setbuf function is equivalent to the setvbuf
The setbuf function returns no value.
<p><b> Forward references</b>: the setvbuf function (<a href="#7.21.5.6">7.21.5.6</a>).
-<a name="7.21.5.6" href="#7.21.5.6"><h5>7.21.5.6 The setvbuf function</h5></a>
+<h5><a name="7.21.5.6" href="#7.21.5.6">7.21.5.6 The setvbuf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int setvbuf(FILE * restrict stream,
char * restrict buf,
- int mode, size_t size);</pre>
+ int mode, size_t size);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The setvbuf function may be used only after the stream pointed to by stream has
before a buffer that has automatic storage duration is deallocated upon block exit.
</small>
-<a name="7.21.6" href="#7.21.6"><h4>7.21.6 Formatted input/output functions</h4></a>
+<h4><a name="7.21.6" href="#7.21.6">7.21.6 Formatted input/output functions</a></h4>
<p><!--para 1 -->
The formatted input/output functions shall behave as if there is a sequence point after the
actions associated with each specifier.<sup><a href="#note267"><b>267)</b></a></sup>
<p><small><a name="note267" href="#note267">267)</a> The fprintf functions perform writes to memory for the %n specifier.
</small>
-<a name="7.21.6.1" href="#7.21.6.1"><h5>7.21.6.1 The fprintf function</h5></a>
+<h5><a name="7.21.6.1" href="#7.21.6.1">7.21.6.1 The fprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int fprintf(FILE * restrict stream,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fprintf function writes output to the stream pointed to by stream, under control
The flag characters and their meanings are:
- The result of the conversion is left-justified within the field. (It is right-justified if
<pre>
- this flag is not specified.)</pre>
+ this flag is not specified.)
+</pre>
+ The result of a signed conversion always begins with a plus or minus sign. (It
<pre>
begins with a sign only when a negative value is converted if this flag is not
- specified.)<sup><a href="#note269"><b>269)</b></a></sup></pre>
+ specified.)<sup><a href="#note269"><b>269)</b></a></sup>
+</pre>
space If the first character of a signed conversion is not a sign, or if a signed conversion
<pre>
results in no characters, a space is prefixed to the result. If the space and + flags
- both appear, the space flag is ignored.</pre>
+ both appear, the space flag is ignored.
+</pre>
# The result is converted to an ''alternative form''. For o conversion, it increases
<pre>
the precision, if and only if necessary, to force the first digit of the result to be a
contains a decimal-point character, even if no digits follow it. (Normally, a
decimal-point character appears in the result of these conversions only if a digit
follows it.) For g and G conversions, trailing zeros are not removed from the
- result. For other conversions, the behavior is undefined.</pre>
+ result. For other conversions, the behavior is undefined.
+</pre>
0 For d, i, o, u, x, X, a, A, e, E, f, F, g, and G conversions, leading zeros
<pre>
(following any indication of sign or base) are used to pad to the field width rather
than performing space padding, except when converting an infinity or NaN. If the
- 0 and - flags both appear, the 0 flag is ignored. For d, i, o, u, x, and X</pre>
+ 0 and - flags both appear, the 0 flag is ignored. For d, i, o, u, x, and X
+</pre>
<!--page 329 -->
-<p><!--para 7 -->
<pre>
conversions, if a precision is specified, the 0 flag is ignored. For other
- conversions, the behavior is undefined.</pre>
+ conversions, the behavior is undefined.
+</pre>
+<p><!--para 7 -->
The length modifiers and their meanings are:
hh Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
been promoted according to the integer promotions, but its value shall be
converted to signed char or unsigned char before printing); or that
a following n conversion specifier applies to a pointer to a signed char
- argument.</pre>
+ argument.
+</pre>
h Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
short int or unsigned short int argument (the argument will
have been promoted according to the integer promotions, but its value shall
be converted to short int or unsigned short int before printing);
or that a following n conversion specifier applies to a pointer to a short
- int argument.</pre>
+ int argument.
+</pre>
l (ell) Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
long int or unsigned long int argument; that a following n
following c conversion specifier applies to a wint_t argument; that a
following s conversion specifier applies to a pointer to a wchar_t
argument; or has no effect on a following a, A, e, E, f, F, g, or G conversion
- specifier.</pre>
+ specifier.
+</pre>
ll (ell-ell) Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
long long int or unsigned long long int argument; or that a
following n conversion specifier applies to a pointer to a long long int
- argument.</pre>
+ argument.
+</pre>
j Specifies that a following d, i, o, u, x, or X conversion specifier applies to
<pre>
an intmax_t or uintmax_t argument; or that a following n conversion
- specifier applies to a pointer to an intmax_t argument.</pre>
+ specifier applies to a pointer to an intmax_t argument.
+</pre>
z Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
size_t or the corresponding signed integer type argument; or that a
following n conversion specifier applies to a pointer to a signed integer type
- corresponding to size_t argument.</pre>
+ corresponding to size_t argument.
+</pre>
t Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<!--page 330 -->
<pre>
ptrdiff_t or the corresponding unsigned integer type argument; or that a
following n conversion specifier applies to a pointer to a ptrdiff_t
- argument.</pre>
+ argument.
+</pre>
L Specifies that a following a, A, e, E, f, F, g, or G conversion specifier
<pre>
- applies to a long double argument.</pre>
+ applies to a long double argument.
+</pre>
If a length modifier appears with any conversion specifier other than as specified above,
the behavior is undefined.
<p><!--para 8 -->
precision specifies the minimum number of digits to appear; if the value
being converted can be represented in fewer digits, it is expanded with
leading zeros. The default precision is 1. The result of converting a zero
- value with a precision of zero is no characters.</pre>
+ value with a precision of zero is no characters.
+</pre>
o,u,x,X The unsigned int argument is converted to unsigned octal (o), unsigned
<pre>
decimal (u), or unsigned hexadecimal notation (x or X) in the style dddd; the
conversion. The precision specifies the minimum number of digits to appear;
if the value being converted can be represented in fewer digits, it is expanded
with leading zeros. The default precision is 1. The result of converting a
- zero value with a precision of zero is no characters.</pre>
+ zero value with a precision of zero is no characters.
+</pre>
f,F A double argument representing a floating-point number is converted to
<pre>
decimal notation in the style [-]ddd.ddd, where the number of digits after
[-]nan or [-]nan(n-char-sequence) -- which style, and the meaning of
any n-char-sequence, is implementation-defined. The F conversion specifier
produces INF, INFINITY, or NAN instead of inf, infinity, or nan,
- respectively.<sup><a href="#note270"><b>270)</b></a></sup></pre>
+ respectively.<sup><a href="#note270"><b>270)</b></a></sup>
+</pre>
e,E A double argument representing a floating-point number is converted in the
<pre>
style [-]d.ddd e(+-)dd, where there is one digit (which is nonzero if the
argument is nonzero) before the decimal-point character and the number of
- digits after it is equal to the precision; if the precision is missing, it is taken as</pre>
+ digits after it is equal to the precision; if the precision is missing, it is taken as
+</pre>
<!--page 331 -->
and only as many more digits as necessary to represent the exponent. If the
value is zero, the exponent is zero.
A double argument representing an infinity or NaN is converted in the style
- of an f or F conversion specifier.</pre>
+ of an f or F conversion specifier.
+</pre>
g,G A double argument representing a floating-point number is converted in
<pre>
style f or e (or in style F or E in the case of a G conversion specifier),
fractional portion of the result and the decimal-point character is removed if
there is no fractional portion remaining.
A double argument representing an infinity or NaN is converted in the style
- of an f or F conversion specifier.</pre>
+ of an f or F conversion specifier.
+</pre>
a,A A double argument representing a floating-point number is converted in the
<pre>
style [-]0xh.hhhh p(+-)d, where there is one hexadecimal digit (which is
of hexadecimal digits after it is equal to the precision; if the precision is
missing and FLT_RADIX is a power of 2, then the precision is sufficient for
an exact representation of the value; if the precision is missing and
- FLT_RADIX is not a power of 2, then the precision is sufficient to</pre>
+ FLT_RADIX is not a power of 2, then the precision is sufficient to
+</pre>
least one digit, and only as many more digits as necessary to represent the
decimal exponent of 2. If the value is zero, the exponent is zero.
A double argument representing an infinity or NaN is converted in the style
- of an f or F conversion specifier.</pre>
+ of an f or F conversion specifier.
+</pre>
c If no l length modifier is present, the int argument is converted to an
<pre>
unsigned char, and the resulting character is written.
an ls conversion specification with no precision and an argument that points
to the initial element of a two-element array of wchar_t, the first element
containing the wint_t argument to the lc conversion specification and the
- second a null wide character.</pre>
+ second a null wide character.
+</pre>
s If no l length modifier is present, the argument shall be a pointer to the initial
<pre>
element of an array of character type.<sup><a href="#note273"><b>273)</b></a></sup> Characters from the array are
(byte). If no precision is specified, the array shall contain a null wide
character. If a precision is specified, no more than that many bytes are
written (including shift sequences, if any), and the array shall contain a null
- wide character if, to equal the multibyte character sequence length given by</pre>
+ wide character if, to equal the multibyte character sequence length given by
+</pre>
<!--page 333 -->
<pre>
the precision, the function would need to access a wide character one past the
- end of the array. In no case is a partial multibyte character written.<sup><a href="#note274"><b>274)</b></a></sup></pre>
+ end of the array. In no case is a partial multibyte character written.<sup><a href="#note274"><b>274)</b></a></sup>
+</pre>
p The argument shall be a pointer to void. The value of the pointer is
<pre>
converted to a sequence of printing characters, in an implementation-defined
- manner.</pre>
+ manner.
+</pre>
n The argument shall be a pointer to signed integer into which is written the
<pre>
number of characters written to the output stream so far by this call to
fprintf. No argument is converted, but one is consumed. If the conversion
specification includes any flags, a field width, or a precision, the behavior is
- undefined.</pre>
+ undefined.
+</pre>
% A % character is written. No argument is converted. The complete
-<p><!--para 9 -->
<pre>
- conversion specification shall be %%.</pre>
+ conversion specification shall be %%.
+</pre>
+<p><!--para 9 -->
If a conversion specification is invalid, the behavior is undefined.<sup><a href="#note275"><b>275)</b></a></sup> If any argument is
not the correct type for the corresponding conversion specification, the behavior is
undefined.
<p><!--para 11 -->
For a and A conversions, if FLT_RADIX is a power of 2, the value is correctly rounded
to a hexadecimal floating number with the given precision.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 12 -->
For a and A conversions, if FLT_RADIX is not a power of 2 and the result is not exactly
representable in the given precision, the result should be one of the two adjacent numbers
<p><!--para 14 -->
The fprintf function returns the number of characters transmitted, or a negative value
if an output or encoding error occurred.
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 15 -->
The number of characters that can be produced by any single conversion shall be at least
4095.
int day, hour, min;
fprintf(stdout, "%s, %s %d, %.2d:%.2d\n",
weekday, month, day, hour, min);
- fprintf(stdout, "pi = %.5f\n", 4 * atan(1.0));</pre>
+ fprintf(stdout, "pi = %.5f\n", 4 * atan(1.0));
+</pre>
<p><!--para 17 -->
EXAMPLE 2 In this example, multibyte characters do not have a state-dependent encoding, and the
<p><!--para 18 -->
Given the following wide string with length seven,
<pre>
- static wchar_t wstr[] = L" X Yabc Z W";</pre>
+ static wchar_t wstr[] = L" X Yabc Z W";
+</pre>
the seven calls
<pre>
fprintf(stdout, "|1234567890123|\n");
fprintf(stdout, "|%13.10ls|\n", wstr);
fprintf(stdout, "|%13.11ls|\n", wstr);
fprintf(stdout, "|%13.15ls|\n", &wstr[2]);
- fprintf(stdout, "|%13lc|\n", (wint_t) wstr[5]);</pre>
+ fprintf(stdout, "|%13lc|\n", (wint_t) wstr[5]);
+</pre>
will print the following seven lines:
<pre>
|1234567890123|
| X Yabc Z|
| X Yabc Z W|
| abc Z W|
- | Z|</pre>
+ | Z|
+</pre>
<p><b> Forward references</b>: conversion state (<a href="#7.28.6">7.28.6</a>), the wcrtomb function (<a href="#7.28.6.3.3">7.28.6.3.3</a>).
<!--page 335 -->
the case of fixed-point conversion by the source value as well.
</small>
-<a name="7.21.6.2" href="#7.21.6.2"><h5>7.21.6.2 The fscanf function</h5></a>
+<h5><a name="7.21.6.2" href="#7.21.6.2">7.21.6.2 The fscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int fscanf(FILE * restrict stream,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fscanf function reads input from the stream pointed to by stream, under control
The length modifiers and their meanings are:
hh Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
- to an argument with type pointer to signed char or unsigned char.</pre>
+ to an argument with type pointer to signed char or unsigned char.
+</pre>
h Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to short int or unsigned short
- int.</pre>
+ int.
+</pre>
l (ell) Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to long int or unsigned long
int; that a following a, A, e, E, f, F, g, or G conversion specifier applies to
an argument with type pointer to double; or that a following c, s, or [
- conversion specifier applies to an argument with type pointer to wchar_t.</pre>
+ conversion specifier applies to an argument with type pointer to wchar_t.
+</pre>
ll (ell-ell) Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to long long int or unsigned
- long long int.</pre>
+ long long int.
+</pre>
<!--page 337 -->
j Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
- to an argument with type pointer to intmax_t or uintmax_t.</pre>
+ to an argument with type pointer to intmax_t or uintmax_t.
+</pre>
z Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to size_t or the corresponding signed
- integer type.</pre>
+ integer type.
+</pre>
t Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to ptrdiff_t or the corresponding
- unsigned integer type.</pre>
+ unsigned integer type.
+</pre>
L Specifies that a following a, A, e, E, f, F, g, or G conversion specifier
<pre>
- applies to an argument with type pointer to long double.</pre>
+ applies to an argument with type pointer to long double.
+</pre>
If a length modifier appears with any conversion specifier other than as specified above,
the behavior is undefined.
<p><!--para 12 -->
<pre>
expected for the subject sequence of the strtol function with the value 10
for the base argument. The corresponding argument shall be a pointer to
- signed integer.</pre>
+ signed integer.
+</pre>
i Matches an optionally signed integer, whose format is the same as expected
<pre>
for the subject sequence of the strtol function with the value 0 for the
base argument. The corresponding argument shall be a pointer to signed
- integer.</pre>
+ integer.
+</pre>
o Matches an optionally signed octal integer, whose format is the same as
<pre>
expected for the subject sequence of the strtoul function with the value 8
for the base argument. The corresponding argument shall be a pointer to
- unsigned integer.</pre>
+ unsigned integer.
+</pre>
u Matches an optionally signed decimal integer, whose format is the same as
<pre>
expected for the subject sequence of the strtoul function with the value 10
for the base argument. The corresponding argument shall be a pointer to
- unsigned integer.</pre>
+ unsigned integer.
+</pre>
x Matches an optionally signed hexadecimal integer, whose format is the same
<pre>
as expected for the subject sequence of the strtoul function with the value
16 for the base argument. The corresponding argument shall be a pointer to
- unsigned integer.</pre>
+ unsigned integer.
+</pre>
a,e,f,g Matches an optionally signed floating-point number, infinity, or NaN, whose
<!--page 338 -->
<pre>
format is the same as expected for the subject sequence of the strtod
- function. The corresponding argument shall be a pointer to floating.</pre>
+ function. The corresponding argument shall be a pointer to floating.
+</pre>
c Matches a sequence of characters of exactly the number specified by the field
<pre>
width (1 if no field width is present in the directive).<sup><a href="#note279"><b>279)</b></a></sup>
initialized to zero before the first multibyte character is converted. The
corresponding argument shall be a pointer to the initial element of an array of
wchar_t large enough to accept the resulting sequence of wide characters.
- No null wide character is added.</pre>
- s Matches a sequence of non-white-space characters.279)
+ No null wide character is added.
+</pre>
+ s Matches a sequence of non-white-space characters.<sup><a href="#note279"><b>279)</b></a></sup>
<pre>
If no l length modifier is present, the corresponding argument shall be a
pointer to the initial element of a character array large enough to accept the
before the first multibyte character is converted. The corresponding argument
shall be a pointer to the initial element of an array of wchar_t large enough
to accept the sequence and the terminating null wide character, which will be
- added automatically.</pre>
+ added automatically.
+</pre>
[ Matches a nonempty sequence of characters from a set of expected characters
<pre>
- (the scanset).279)
+ (the scanset).<sup><a href="#note279"><b>279)</b></a></sup>
If no l length modifier is present, the corresponding argument shall be a
pointer to the initial element of a character array large enough to accept the
sequence and a terminating null character, which will be added automatically.
If an l length modifier is present, the input shall be a sequence of multibyte
characters that begins in the initial shift state. Each multibyte character is
converted to a wide character as if by a call to the mbrtowc function, with
- the conversion state described by an mbstate_t object initialized to zero</pre>
+ the conversion state described by an mbstate_t object initialized to zero
+</pre>
<!--page 339 -->
<pre>
the first following right bracket character is the one that ends the
specification. If a - character is in the scanlist and is not the first, nor the
second where the first character is a ^, nor the last character, the behavior is
- implementation-defined.</pre>
+ implementation-defined.
+</pre>
p Matches an implementation-defined set of sequences, which should be the
<pre>
same as the set of sequences that may be produced by the %p conversion of
pointer to void. The input item is converted to a pointer value in an
implementation-defined manner. If the input item is a value converted earlier
during the same program execution, the pointer that results shall compare
- equal to that value; otherwise the behavior of the %p conversion is undefined.</pre>
+ equal to that value; otherwise the behavior of the %p conversion is undefined.
+</pre>
n No input is consumed. The corresponding argument shall be a pointer to
<pre>
signed integer into which is to be written the number of characters read from
%n directive does not increment the assignment count returned at the
completion of execution of the fscanf function. No argument is converted,
but one is consumed. If the conversion specification includes an assignment-
- suppressing character or a field width, the behavior is undefined.</pre>
+ suppressing character or a field width, the behavior is undefined.
+</pre>
% Matches a single % character; no conversion or assignment occurs. The
-<p><!--para 13 -->
<pre>
- complete conversion specification shall be %%.</pre>
+ complete conversion specification shall be %%.
+</pre>
+<p><!--para 13 -->
If a conversion specification is invalid, the behavior is undefined.<sup><a href="#note280"><b>280)</b></a></sup>
<p><!--para 14 -->
The conversion specifiers A, E, F, G, and X are also valid and behave the same as,
#include <a href="#7.21"><stdio.h></a>
/* ... */
int n, i; float x; char name[50];
- n = fscanf(stdin, "%d%f%s", &i, &x, name);</pre>
+ n = fscanf(stdin, "%d%f%s", &i, &x, name);
+</pre>
with the input line:
<pre>
- 25 54.32E-1 thompson</pre>
+ 25 54.32E-1 thompson
+</pre>
will assign to n the value 3, to i the value 25, to x the value 5.432, and to name the sequence
thompson\0.
#include <a href="#7.21"><stdio.h></a>
/* ... */
int i; float x; char name[50];
- fscanf(stdin, "%2d%f%*d %[0123456789]", &i, &x, name);</pre>
+ fscanf(stdin, "%2d%f%*d %[0123456789]", &i, &x, name);
+</pre>
with input:
<pre>
- 56789 0123 56a72</pre>
+ 56789 0123 56a72
+</pre>
will assign to i the value 56 and to x the value 789.0, will skip 0123, and will assign to name the
sequence 56\0. The next character read from the input stream will be a.
<p><!--para 19 -->
EXAMPLE 3 To accept repeatedly from stdin a quantity, a unit of measure, and an item name:
-<p><!--para 20 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
/* ... */
do {
count = fscanf(stdin, "%f%20s of %20s", &quant, units, item);
fscanf(stdin,"%*[^\n]");
- } while (!feof(stdin) && !ferror(stdin));</pre>
+ } while (!feof(stdin) && !ferror(stdin));
+</pre>
+<p><!--para 20 -->
If the stdin stream contains the following lines:
<!--page 341 -->
<pre>
lots of luck
10.0LBS of
dirt
- 100ergs of energy</pre>
+ 100ergs of energy
+</pre>
the execution of the above example will be analogous to the following assignments:
<pre>
quant = 2; strcpy(units, "quarts"); strcpy(item, "oil");
quant = 10.0; strcpy(units, "LBS"); strcpy(item, "dirt");
count = 3;
count = 0; // "100e" fails to match "%f"
- count = EOF;</pre>
+ count = EOF;
+</pre>
<p><!--para 21 -->
EXAMPLE 4 In:
#include <a href="#7.21"><stdio.h></a>
/* ... */
int d1, d2, n1, n2, i;
- i = sscanf("123", "%d%n%n%d", &d1, &n1, &n2, &d2);</pre>
+ i = sscanf("123", "%d%n%n%d", &d1, &n1, &n2, &d2);
+</pre>
the value 123 is assigned to d1 and the value 3 to n1. Because %n can never get an input failure the value
of 3 is also assigned to n2. The value of d2 is not affected. The value 1 is assigned to i.
#include <a href="#7.21"><stdio.h></a>
/* ... */
char str[50];
- fscanf(stdin, "a%s", str);</pre>
+ fscanf(stdin, "a%s", str);
+</pre>
with the input line:
<pre>
- a(uparrow) X Y(downarrow) bc</pre>
+ a(uparrow) X Y(downarrow) bc
+</pre>
str will contain (uparrow) X Y(downarrow)\0 assuming that none of the bytes of the shift sequences (or of the multibyte
characters, in the more general case) appears to be a single-byte white-space character.
<p><!--para 24 -->
#include <a href="#7.19"><stddef.h></a>
/* ... */
wchar_t wstr[50];
- fscanf(stdin, "a%ls", wstr);</pre>
+ fscanf(stdin, "a%ls", wstr);
+</pre>
with the same input line, wstr will contain the two wide characters that correspond to X and Y and a
terminating null wide character.
<p><!--para 25 -->
#include <a href="#7.19"><stddef.h></a>
/* ... */
wchar_t wstr[50];
- fscanf(stdin, "a(uparrow) X(downarrow)%ls", wstr);</pre>
+ fscanf(stdin, "a(uparrow) X(downarrow)%ls", wstr);
+</pre>
with the same input line will return zero due to a matching failure against the (downarrow) sequence in the format
string.
<p><!--para 26 -->
#include <a href="#7.19"><stddef.h></a>
/* ... */
wchar_t wstr[50];
- fscanf(stdin, "a(uparrow) Y(downarrow)%ls", wstr);</pre>
+ fscanf(stdin, "a(uparrow) Y(downarrow)%ls", wstr);
+</pre>
with the same input line, zero will again be returned, but stdin will be left with a partially consumed
multibyte character.
<p><small><a name="note280" href="#note280">280)</a> See ''future library directions'' (<a href="#7.30.9">7.30.9</a>).
</small>
-<a name="7.21.6.3" href="#7.21.6.3"><h5>7.21.6.3 The printf function</h5></a>
+<h5><a name="7.21.6.3" href="#7.21.6.3">7.21.6.3 The printf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int printf(const char * restrict format, ...);</pre>
+ int printf(const char * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The printf function is equivalent to fprintf with the argument stdout interposed
The printf function returns the number of characters transmitted, or a negative value if
an output or encoding error occurred.
-<a name="7.21.6.4" href="#7.21.6.4"><h5>7.21.6.4 The scanf function</h5></a>
+<h5><a name="7.21.6.4" href="#7.21.6.4">7.21.6.4 The scanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int scanf(const char * restrict format, ...);</pre>
+ int scanf(const char * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The scanf function is equivalent to fscanf with the argument stdin interposed
number of input items assigned, which can be fewer than provided for, or even zero, in
the event of an early matching failure.
-<a name="7.21.6.5" href="#7.21.6.5"><h5>7.21.6.5 The snprintf function</h5></a>
+<h5><a name="7.21.6.5" href="#7.21.6.5">7.21.6.5 The snprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int snprintf(char * restrict s, size_t n,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The snprintf function is equivalent to fprintf, except that the output is written into
value if an encoding error occurred. Thus, the null-terminated output has been
completely written if and only if the returned value is nonnegative and less than n.
-<a name="7.21.6.6" href="#7.21.6.6"><h5>7.21.6.6 The sprintf function</h5></a>
+<h5><a name="7.21.6.6" href="#7.21.6.6">7.21.6.6 The sprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int sprintf(char * restrict s,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The sprintf function is equivalent to fprintf, except that the output is written into
counting the terminating null character, or a negative value if an encoding error occurred.
<!--page 344 -->
-<a name="7.21.6.7" href="#7.21.6.7"><h5>7.21.6.7 The sscanf function</h5></a>
+<h5><a name="7.21.6.7" href="#7.21.6.7">7.21.6.7 The sscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int sscanf(const char * restrict s,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The sscanf function is equivalent to fscanf, except that input is obtained from a
returns the number of input items assigned, which can be fewer than provided for, or even
zero, in the event of an early matching failure.
-<a name="7.21.6.8" href="#7.21.6.8"><h5>7.21.6.8 The vfprintf function</h5></a>
+<h5><a name="7.21.6.8" href="#7.21.6.8">7.21.6.8 The vfprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vfprintf(FILE * restrict stream,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vfprintf function is equivalent to fprintf, with the variable argument list
// print out remainder of message
vfprintf(stderr, format, args);
va_end(args);
- }</pre>
+ }
+</pre>
<h6>footnotes</h6>
vsscanf invoke the va_arg macro, the value of arg after the return is indeterminate.
</small>
-<a name="7.21.6.9" href="#7.21.6.9"><h5>7.21.6.9 The vfscanf function</h5></a>
+<h5><a name="7.21.6.9" href="#7.21.6.9">7.21.6.9 The vfscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vfscanf(FILE * restrict stream,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vfscanf function is equivalent to fscanf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vfscanf function does not invoke the
- va_end macro.281)
+ va_end macro.<sup><a href="#note281"><b>281)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vfscanf function returns the value of the macro EOF if an input failure occurs
returns the number of input items assigned, which can be fewer than provided for, or even
zero, in the event of an early matching failure.
-<a name="7.21.6.10" href="#7.21.6.10"><h5>7.21.6.10 The vprintf function</h5></a>
+<h5><a name="7.21.6.10" href="#7.21.6.10">7.21.6.10 The vprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
#include <a href="#7.21"><stdio.h></a>
int vprintf(const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vprintf function is equivalent to printf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
<!--page 346 -->
possibly subsequent va_arg calls). The vprintf function does not invoke the
- va_end macro.281)
+ va_end macro.<sup><a href="#note281"><b>281)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vprintf function returns the number of characters transmitted, or a negative value
if an output or encoding error occurred.
-<a name="7.21.6.11" href="#7.21.6.11"><h5>7.21.6.11 The vscanf function</h5></a>
+<h5><a name="7.21.6.11" href="#7.21.6.11">7.21.6.11 The vscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
#include <a href="#7.21"><stdio.h></a>
int vscanf(const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vscanf function is equivalent to scanf, with the variable argument list replaced
by arg, which shall have been initialized by the va_start macro (and possibly
subsequent va_arg calls). The vscanf function does not invoke the va_end
- macro.281)
+ macro.<sup><a href="#note281"><b>281)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vscanf function returns the value of the macro EOF if an input failure occurs
returns the number of input items assigned, which can be fewer than provided for, or even
zero, in the event of an early matching failure.
-<a name="7.21.6.12" href="#7.21.6.12"><h5>7.21.6.12 The vsnprintf function</h5></a>
+<h5><a name="7.21.6.12" href="#7.21.6.12">7.21.6.12 The vsnprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vsnprintf(char * restrict s, size_t n,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vsnprintf function is equivalent to snprintf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vsnprintf function does not invoke the
- va_end macro.281) If copying takes place between objects that overlap, the behavior is
+ va_end macro.<sup><a href="#note281"><b>281)</b></a></sup> If copying takes place between objects that overlap, the behavior is
undefined.
<!--page 347 -->
<h6>Returns</h6>
value if an encoding error occurred. Thus, the null-terminated output has been
completely written if and only if the returned value is nonnegative and less than n.
-<a name="7.21.6.13" href="#7.21.6.13"><h5>7.21.6.13 The vsprintf function</h5></a>
+<h5><a name="7.21.6.13" href="#7.21.6.13">7.21.6.13 The vsprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vsprintf(char * restrict s,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vsprintf function is equivalent to sprintf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vsprintf function does not invoke the
- va_end macro.281) If copying takes place between objects that overlap, the behavior is
+ va_end macro.<sup><a href="#note281"><b>281)</b></a></sup> If copying takes place between objects that overlap, the behavior is
undefined.
<h6>Returns</h6>
<p><!--para 3 -->
The vsprintf function returns the number of characters written in the array, not
counting the terminating null character, or a negative value if an encoding error occurred.
-<a name="7.21.6.14" href="#7.21.6.14"><h5>7.21.6.14 The vsscanf function</h5></a>
+<h5><a name="7.21.6.14" href="#7.21.6.14">7.21.6.14 The vsscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vsscanf(const char * restrict s,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vsscanf function is equivalent to sscanf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vsscanf function does not invoke the
- va_end macro.281)
+ va_end macro.<sup><a href="#note281"><b>281)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vsscanf function returns the value of the macro EOF if an input failure occurs
returns the number of input items assigned, which can be fewer than provided for, or even
zero, in the event of an early matching failure.
-<a name="7.21.7" href="#7.21.7"><h4>7.21.7 Character input/output functions</h4></a>
+<h4><a name="7.21.7" href="#7.21.7">7.21.7 Character input/output functions</a></h4>
-<a name="7.21.7.1" href="#7.21.7.1"><h5>7.21.7.1 The fgetc function</h5></a>
+<h5><a name="7.21.7.1" href="#7.21.7.1">7.21.7.1 The fgetc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int fgetc(FILE *stream);</pre>
+ int fgetc(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If the end-of-file indicator for the input stream pointed to by stream is not set and a
<p><small><a name="note282" href="#note282">282)</a> An end-of-file and a read error can be distinguished by use of the feof and ferror functions.
</small>
-<a name="7.21.7.2" href="#7.21.7.2"><h5>7.21.7.2 The fgets function</h5></a>
+<h5><a name="7.21.7.2" href="#7.21.7.2">7.21.7.2 The fgets function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
char *fgets(char * restrict s, int n,
- FILE * restrict stream);</pre>
+ FILE * restrict stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fgets function reads at most one less than the number of characters specified by n
<!--page 349 -->
-<a name="7.21.7.3" href="#7.21.7.3"><h5>7.21.7.3 The fputc function</h5></a>
+<h5><a name="7.21.7.3" href="#7.21.7.3">7.21.7.3 The fputc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int fputc(int c, FILE *stream);</pre>
+ int fputc(int c, FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fputc function writes the character specified by c (converted to an unsigned
The fputc function returns the character written. If a write error occurs, the error
indicator for the stream is set and fputc returns EOF.
-<a name="7.21.7.4" href="#7.21.7.4"><h5>7.21.7.4 The fputs function</h5></a>
+<h5><a name="7.21.7.4" href="#7.21.7.4">7.21.7.4 The fputs function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int fputs(const char * restrict s,
- FILE * restrict stream);</pre>
+ FILE * restrict stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fputs function writes the string pointed to by s to the stream pointed to by
The fputs function returns EOF if a write error occurs; otherwise it returns a
nonnegative value.
-<a name="7.21.7.5" href="#7.21.7.5"><h5>7.21.7.5 The getc function</h5></a>
+<h5><a name="7.21.7.5" href="#7.21.7.5">7.21.7.5 The getc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int getc(FILE *stream);</pre>
+ int getc(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The getc function is equivalent to fgetc, except that if it is implemented as a macro, it
getc returns EOF. If a read error occurs, the error indicator for the stream is set and
getc returns EOF.
-<a name="7.21.7.6" href="#7.21.7.6"><h5>7.21.7.6 The getchar function</h5></a>
+<h5><a name="7.21.7.6" href="#7.21.7.6">7.21.7.6 The getchar function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int getchar(void);</pre>
+ int getchar(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The getchar function is equivalent to getc with the argument stdin.
getchar returns EOF. If a read error occurs, the error indicator for the stream is set and
getchar returns EOF. *
-<a name="7.21.7.7" href="#7.21.7.7"><h5>7.21.7.7 The putc function</h5></a>
+<h5><a name="7.21.7.7" href="#7.21.7.7">7.21.7.7 The putc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int putc(int c, FILE *stream);</pre>
+ int putc(int c, FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The putc function is equivalent to fputc, except that if it is implemented as a macro, it
The putc function returns the character written. If a write error occurs, the error
indicator for the stream is set and putc returns EOF.
-<a name="7.21.7.8" href="#7.21.7.8"><h5>7.21.7.8 The putchar function</h5></a>
+<h5><a name="7.21.7.8" href="#7.21.7.8">7.21.7.8 The putchar function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int putchar(int c);</pre>
+ int putchar(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The putchar function is equivalent to putc with the second argument stdout.
The putchar function returns the character written. If a write error occurs, the error
indicator for the stream is set and putchar returns EOF.
-<a name="7.21.7.9" href="#7.21.7.9"><h5>7.21.7.9 The puts function</h5></a>
+<h5><a name="7.21.7.9" href="#7.21.7.9">7.21.7.9 The puts function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int puts(const char *s);</pre>
+ int puts(const char *s);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The puts function writes the string pointed to by s to the stream pointed to by stdout,
The puts function returns EOF if a write error occurs; otherwise it returns a nonnegative
value.
-<a name="7.21.7.10" href="#7.21.7.10"><h5>7.21.7.10 The ungetc function</h5></a>
+<h5><a name="7.21.7.10" href="#7.21.7.10">7.21.7.10 The ungetc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int ungetc(int c, FILE *stream);</pre>
+ int ungetc(int c, FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ungetc function pushes the character specified by c (converted to an unsigned
<p><small><a name="note283" href="#note283">283)</a> See ''future library directions'' (<a href="#7.30.9">7.30.9</a>).
</small>
-<a name="7.21.8" href="#7.21.8"><h4>7.21.8 Direct input/output functions</h4></a>
+<h4><a name="7.21.8" href="#7.21.8">7.21.8 Direct input/output functions</a></h4>
-<a name="7.21.8.1" href="#7.21.8.1"><h5>7.21.8.1 The fread function</h5></a>
+<h5><a name="7.21.8.1" href="#7.21.8.1">7.21.8.1 The fread function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
size_t fread(void * restrict ptr,
size_t size, size_t nmemb,
- FILE * restrict stream);</pre>
+ FILE * restrict stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fread function reads, into the array pointed to by ptr, up to nmemb elements
<!--page 353 -->
-<a name="7.21.8.2" href="#7.21.8.2"><h5>7.21.8.2 The fwrite function</h5></a>
+<h5><a name="7.21.8.2" href="#7.21.8.2">7.21.8.2 The fwrite function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
size_t fwrite(const void * restrict ptr,
size_t size, size_t nmemb,
- FILE * restrict stream);</pre>
+ FILE * restrict stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fwrite function writes, from the array pointed to by ptr, up to nmemb elements
less than nmemb only if a write error is encountered. If size or nmemb is zero,
fwrite returns zero and the state of the stream remains unchanged.
-<a name="7.21.9" href="#7.21.9"><h4>7.21.9 File positioning functions</h4></a>
+<h4><a name="7.21.9" href="#7.21.9">7.21.9 File positioning functions</a></h4>
-<a name="7.21.9.1" href="#7.21.9.1"><h5>7.21.9.1 The fgetpos function</h5></a>
+<h5><a name="7.21.9.1" href="#7.21.9.1">7.21.9.1 The fgetpos function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int fgetpos(FILE * restrict stream,
- fpos_t * restrict pos);</pre>
+ fpos_t * restrict pos);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fgetpos function stores the current values of the parse state (if any) and file
<p><b> Forward references</b>: the fsetpos function (<a href="#7.21.9.3">7.21.9.3</a>).
<!--page 354 -->
-<a name="7.21.9.2" href="#7.21.9.2"><h5>7.21.9.2 The fseek function</h5></a>
+<h5><a name="7.21.9.2" href="#7.21.9.2">7.21.9.2 The fseek function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int fseek(FILE *stream, long int offset, int whence);</pre>
+ int fseek(FILE *stream, long int offset, int whence);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fseek function sets the file position indicator for the stream pointed to by stream.
The fseek function returns nonzero only for a request that cannot be satisfied.
<p><b> Forward references</b>: the ftell function (<a href="#7.21.9.4">7.21.9.4</a>).
-<a name="7.21.9.3" href="#7.21.9.3"><h5>7.21.9.3 The fsetpos function</h5></a>
+<h5><a name="7.21.9.3" href="#7.21.9.3">7.21.9.3 The fsetpos function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int fsetpos(FILE *stream, const fpos_t *pos);</pre>
+ int fsetpos(FILE *stream, const fpos_t *pos);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fsetpos function sets the mbstate_t object (if any) and file position indicator
If successful, the fsetpos function returns zero; on failure, the fsetpos function
returns nonzero and stores an implementation-defined positive value in errno.
-<a name="7.21.9.4" href="#7.21.9.4"><h5>7.21.9.4 The ftell function</h5></a>
+<h5><a name="7.21.9.4" href="#7.21.9.4">7.21.9.4 The ftell function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- long int ftell(FILE *stream);</pre>
+ long int ftell(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ftell function obtains the current value of the file position indicator for the stream
for the stream. On failure, the ftell function returns -1L and stores an
implementation-defined positive value in errno.
-<a name="7.21.9.5" href="#7.21.9.5"><h5>7.21.9.5 The rewind function</h5></a>
+<h5><a name="7.21.9.5" href="#7.21.9.5">7.21.9.5 The rewind function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- void rewind(FILE *stream);</pre>
+ void rewind(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The rewind function sets the file position indicator for the stream pointed to by
stream to the beginning of the file. It is equivalent to
<pre>
- (void)fseek(stream, 0L, SEEK_SET)</pre>
+ (void)fseek(stream, 0L, SEEK_SET)
+</pre>
except that the error indicator for the stream is also cleared.
<h6>Returns</h6>
<p><!--para 3 -->
The rewind function returns no value.
<!--page 356 -->
-<a name="7.21.10" href="#7.21.10"><h4>7.21.10 Error-handling functions</h4></a>
+<h4><a name="7.21.10" href="#7.21.10">7.21.10 Error-handling functions</a></h4>
-<a name="7.21.10.1" href="#7.21.10.1"><h5>7.21.10.1 The clearerr function</h5></a>
+<h5><a name="7.21.10.1" href="#7.21.10.1">7.21.10.1 The clearerr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- void clearerr(FILE *stream);</pre>
+ void clearerr(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The clearerr function clears the end-of-file and error indicators for the stream pointed
<p><!--para 3 -->
The clearerr function returns no value.
-<a name="7.21.10.2" href="#7.21.10.2"><h5>7.21.10.2 The feof function</h5></a>
+<h5><a name="7.21.10.2" href="#7.21.10.2">7.21.10.2 The feof function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int feof(FILE *stream);</pre>
+ int feof(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The feof function tests the end-of-file indicator for the stream pointed to by stream.
The feof function returns nonzero if and only if the end-of-file indicator is set for
stream.
-<a name="7.21.10.3" href="#7.21.10.3"><h5>7.21.10.3 The ferror function</h5></a>
+<h5><a name="7.21.10.3" href="#7.21.10.3">7.21.10.3 The ferror function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- int ferror(FILE *stream);</pre>
+ int ferror(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ferror function tests the error indicator for the stream pointed to by stream.
stream.
<!--page 357 -->
-<a name="7.21.10.4" href="#7.21.10.4"><h5>7.21.10.4 The perror function</h5></a>
+<h5><a name="7.21.10.4" href="#7.21.10.4">7.21.10.4 The perror function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
- void perror(const char *s);</pre>
+ void perror(const char *s);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The perror function maps the error number in the integer expression errno to an
<p><b> Forward references</b>: the strerror function (<a href="#7.23.6.2">7.23.6.2</a>).
<!--page 358 -->
-<a name="7.22" href="#7.22"><h3>7.22 General utilities <stdlib.h></h3></a>
+<h3><a name="7.22" href="#7.22">7.22 General utilities <stdlib.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.22"><stdlib.h></a> declares five types and several functions of general utility, and
defines several macros.<sup><a href="#note284"><b>284)</b></a></sup>
<p><!--para 2 -->
The types declared are size_t and wchar_t (both described in <a href="#7.19">7.19</a>),
<pre>
- div_t</pre>
+ div_t
+</pre>
which is a structure type that is the type of the value returned by the div function,
<pre>
- ldiv_t</pre>
+ ldiv_t
+</pre>
which is a structure type that is the type of the value returned by the ldiv function, and
<pre>
- lldiv_t</pre>
+ lldiv_t
+</pre>
which is a structure type that is the type of the value returned by the lldiv function.
<p><!--para 3 -->
The macros defined are NULL (described in <a href="#7.19">7.19</a>);
<pre>
- EXIT_FAILURE</pre>
+ EXIT_FAILURE
+</pre>
and
<pre>
- EXIT_SUCCESS</pre>
+ EXIT_SUCCESS
+</pre>
which expand to integer constant expressions that can be used as the argument to the
exit function to return unsuccessful or successful termination status, respectively, to the
host environment;
<pre>
- RAND_MAX</pre>
+ RAND_MAX
+</pre>
which expands to an integer constant expression that is the maximum value returned by
the rand function; and
<pre>
- MB_CUR_MAX</pre>
+ MB_CUR_MAX
+</pre>
which expands to a positive integer expression with type size_t that is the maximum
number of bytes in a multibyte character for the extended character set specified by the
current locale (category LC_CTYPE), which is never greater than MB_LEN_MAX.
<p><small><a name="note284" href="#note284">284)</a> See ''future library directions'' (<a href="#7.30.10">7.30.10</a>).
</small>
-<a name="7.22.1" href="#7.22.1"><h4>7.22.1 Numeric conversion functions</h4></a>
+<h4><a name="7.22.1" href="#7.22.1">7.22.1 Numeric conversion functions</a></h4>
<p><!--para 1 -->
The functions atof, atoi, atol, and atoll need not affect the value of the integer
expression errno on an error. If the value of the result cannot be represented, the
behavior is undefined.
-<a name="7.22.1.1" href="#7.22.1.1"><h5>7.22.1.1 The atof function</h5></a>
+<h5><a name="7.22.1.1" href="#7.22.1.1">7.22.1.1 The atof function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- double atof(const char *nptr);</pre>
+ double atof(const char *nptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The atof function converts the initial portion of the string pointed to by nptr to
double representation. Except for the behavior on error, it is equivalent to
<pre>
- strtod(nptr, (char **)NULL)</pre>
+ strtod(nptr, (char **)NULL)
+</pre>
<h6>Returns</h6>
<p><!--para 3 -->
The atof function returns the converted value.
<p><b> Forward references</b>: the strtod, strtof, and strtold functions (<a href="#7.22.1.3">7.22.1.3</a>).
-<a name="7.22.1.2" href="#7.22.1.2"><h5>7.22.1.2 The atoi, atol, and atoll functions</h5></a>
+<h5><a name="7.22.1.2" href="#7.22.1.2">7.22.1.2 The atoi, atol, and atoll functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
int atoi(const char *nptr);
long int atol(const char *nptr);
- long long int atoll(const char *nptr);</pre>
+ long long int atoll(const char *nptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The atoi, atol, and atoll functions convert the initial portion of the string pointed
<pre>
atoi: (int)strtol(nptr, (char **)NULL, 10)
atol: strtol(nptr, (char **)NULL, 10)
- atoll: strtoll(nptr, (char **)NULL, 10)</pre>
+ atoll: strtoll(nptr, (char **)NULL, 10)
+</pre>
<h6>Returns</h6>
<p><!--para 3 -->
The atoi, atol, and atoll functions return the converted value.
(<a href="#7.22.1.4">7.22.1.4</a>).
<!--page 360 -->
-<a name="7.22.1.3" href="#7.22.1.3"><h5>7.22.1.3 The strtod, strtof, and strtold functions</h5></a>
+<h5><a name="7.22.1.3" href="#7.22.1.3">7.22.1.3 The strtod, strtof, and strtold functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
float strtof(const char * restrict nptr,
char ** restrict endptr);
long double strtold(const char * restrict nptr,
- char ** restrict endptr);</pre>
+ char ** restrict endptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strtod, strtof, and strtold functions convert the initial portion of the string
<li> a 0x or 0X, then a nonempty sequence of hexadecimal digits optionally containing a
decimal-point character, then an optional binary exponent part as defined in <a href="#6.4.4.2">6.4.4.2</a>;
<li> INF or INFINITY, ignoring case
-<li> NAN or NAN(n-char-sequenceopt), ignoring case in the NAN part, where:
+<li> NAN or NAN(n-char-sequence<sub>opt</sub>), ignoring case in the NAN part, where:
<pre>
n-char-sequence:
digit
nondigit
n-char-sequence digit
- n-char-sequence nondigit</pre>
+ n-char-sequence nondigit
+</pre>
</ul>
The subject sequence is defined as the longest initial subsequence of the input string,
starting with the first non-white-space character, that is of the expected form. The subject
the subject sequence begins with a minus sign, the sequence is interpreted as negated.<sup><a href="#note285"><b>285)</b></a></sup>
A character sequence INF or INFINITY is interpreted as an infinity, if representable in
the return type, else like a floating constant that is too large for the range of the return
- type. A character sequence NAN or NAN(n-char-sequenceopt), is interpreted as a quiet
+ type. A character sequence NAN or NAN(n-char-sequence<sub>opt</sub>), is interpreted as a quiet
NaN, if supported in the return type, else like a subject sequence part that does not have
the expected form; the meaning of the n-char sequences is implementation-defined.<sup><a href="#note286"><b>286)</b></a></sup> A
pointer to the final string is stored in the object pointed to by endptr, provided that
If the subject sequence is empty or does not have the expected form, no conversion is
performed; the value of nptr is stored in the object pointed to by endptr, provided
that endptr is not a null pointer.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 8 -->
If the subject sequence has the hexadecimal form, FLT_RADIX is not a power of 2, and
the result is not exactly representable, the result should be one of the two numbers in the
to the same internal floating value, but if not will round to adjacent values.
</small>
-<a name="7.22.1.4" href="#7.22.1.4"><h5>7.22.1.4 The strtol, strtoll, strtoul, and strtoull functions</h5></a>
+<h5><a name="7.22.1.4" href="#7.22.1.4">7.22.1.4 The strtol, strtoll, strtoul, and strtoull functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
unsigned long long int strtoull(
const char * restrict nptr,
char ** restrict endptr,
- int base);</pre>
+ int base);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strtol, strtoll, strtoul, and strtoull functions convert the initial
and sign of the value, if any), and the value of the macro ERANGE is stored in errno.
<!--page 364 -->
-<a name="7.22.2" href="#7.22.2"><h4>7.22.2 Pseudo-random sequence generation functions</h4></a>
+<h4><a name="7.22.2" href="#7.22.2">7.22.2 Pseudo-random sequence generation functions</a></h4>
-<a name="7.22.2.1" href="#7.22.2.1"><h5>7.22.2.1 The rand function</h5></a>
+<h5><a name="7.22.2.1" href="#7.22.2.1">7.22.2.1 The rand function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- int rand(void);</pre>
+ int rand(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The rand function computes a sequence of pseudo-random integers in the range 0 to
<h6>Returns</h6>
<p><!--para 4 -->
The rand function returns a pseudo-random integer.
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 5 -->
The value of the RAND_MAX macro shall be at least 32767.
particular requirements should use a generator that is known to be sufficient for their needs.
</small>
-<a name="7.22.2.2" href="#7.22.2.2"><h5>7.22.2.2 The srand function</h5></a>
+<h5><a name="7.22.2.2" href="#7.22.2.2">7.22.2.2 The srand function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- void srand(unsigned int seed);</pre>
+ void srand(unsigned int seed);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The srand function uses the argument as a seed for a new sequence of pseudo-random
void srand(unsigned int seed)
{
next = seed;
- }</pre>
+ }
+</pre>
-<a name="7.22.3" href="#7.22.3"><h4>7.22.3 Memory management functions</h4></a>
+<h4><a name="7.22.3" href="#7.22.3">7.22.3 Memory management functions</a></h4>
<p><!--para 1 -->
The order and contiguity of storage allocated by successive calls to the
aligned_alloc, calloc, malloc, and realloc functions is unspecified. The
is returned, or the behavior is as if the size were some nonzero value, except that the
returned pointer shall not be used to access an object.
-<a name="7.22.3.1" href="#7.22.3.1"><h5>7.22.3.1 The aligned_alloc function</h5></a>
+<h5><a name="7.22.3.1" href="#7.22.3.1">7.22.3.1 The aligned_alloc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- void *aligned_alloc(size_t alignment, size_t size);</pre>
+ void *aligned_alloc(size_t alignment, size_t size);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The aligned_alloc function allocates space for an object whose alignment is
space.
<!--page 366 -->
-<a name="7.22.3.2" href="#7.22.3.2"><h5>7.22.3.2 The calloc function</h5></a>
+<h5><a name="7.22.3.2" href="#7.22.3.2">7.22.3.2 The calloc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- void *calloc(size_t nmemb, size_t size);</pre>
+ void *calloc(size_t nmemb, size_t size);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The calloc function allocates space for an array of nmemb objects, each of whose size
constant.
</small>
-<a name="7.22.3.3" href="#7.22.3.3"><h5>7.22.3.3 The free function</h5></a>
+<h5><a name="7.22.3.3" href="#7.22.3.3">7.22.3.3 The free function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- void free(void *ptr);</pre>
+ void free(void *ptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The free function causes the space pointed to by ptr to be deallocated, that is, made
<p><!--para 3 -->
The free function returns no value.
-<a name="7.22.3.4" href="#7.22.3.4"><h5>7.22.3.4 The malloc function</h5></a>
+<h5><a name="7.22.3.4" href="#7.22.3.4">7.22.3.4 The malloc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- void *malloc(size_t size);</pre>
+ void *malloc(size_t size);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The malloc function allocates space for an object whose size is specified by size and
<p><!--para 3 -->
The malloc function returns either a null pointer or a pointer to the allocated space.
-<a name="7.22.3.5" href="#7.22.3.5"><h5>7.22.3.5 The realloc function</h5></a>
+<h5><a name="7.22.3.5" href="#7.22.3.5">7.22.3.5 The realloc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- void *realloc(void *ptr, size_t size);</pre>
+ void *realloc(void *ptr, size_t size);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The realloc function deallocates the old object pointed to by ptr and returns a
value as a pointer to the old object), or a null pointer if the new object could not be
allocated.
-<a name="7.22.4" href="#7.22.4"><h4>7.22.4 Communication with the environment</h4></a>
+<h4><a name="7.22.4" href="#7.22.4">7.22.4 Communication with the environment</a></h4>
-<a name="7.22.4.1" href="#7.22.4.1"><h5>7.22.4.1 The abort function</h5></a>
+<h5><a name="7.22.4.1" href="#7.22.4.1">7.22.4.1 The abort function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- _Noreturn void abort(void);</pre>
+ _Noreturn void abort(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The abort function causes abnormal program termination to occur, unless the signal
<p><!--para 3 -->
The abort function does not return to its caller.
-<a name="7.22.4.2" href="#7.22.4.2"><h5>7.22.4.2 The atexit function</h5></a>
+<h5><a name="7.22.4.2" href="#7.22.4.2">7.22.4.2 The atexit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- int atexit(void (*func)(void));</pre>
+ int atexit(void (*func)(void));
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The atexit function registers the function pointed to by func, to be called without
arguments at normal program termination.<sup><a href="#note290"><b>290)</b></a></sup>
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 3 -->
The implementation shall support the registration of at least 32 functions.
<h6>Returns</h6>
applications may need to call both registration functions with the same argument.
</small>
-<a name="7.22.4.3" href="#7.22.4.3"><h5>7.22.4.3 The at_quick_exit function</h5></a>
+<h5><a name="7.22.4.3" href="#7.22.4.3">7.22.4.3 The at_quick_exit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- int at_quick_exit(void (*func)(void));</pre>
+ int at_quick_exit(void (*func)(void));
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The at_quick_exit function registers the function pointed to by func, to be called
without arguments should quick_exit be called.<sup><a href="#note291"><b>291)</b></a></sup>
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 3 -->
The implementation shall support the registration of at least 32 functions.
<h6>Returns</h6>
applications may need to call both registration functions with the same argument.
</small>
-<a name="7.22.4.4" href="#7.22.4.4"><h5>7.22.4.4 The exit function</h5></a>
+<h5><a name="7.22.4.4" href="#7.22.4.4">7.22.4.4 The exit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- _Noreturn void exit(int status);</pre>
+ _Noreturn void exit(int status);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The exit function causes normal program termination to occur. No functions registered
other registered functions.
</small>
-<a name="7.22.4.5" href="#7.22.4.5"><h5>7.22.4.5 The _Exit function</h5></a>
+<h5><a name="7.22.4.5" href="#7.22.4.5">7.22.4.5 The _Exit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- _Noreturn void _Exit(int status);</pre>
+ _Noreturn void _Exit(int status);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The _Exit function causes normal program termination to occur and control to be
<p><!--para 3 -->
The _Exit function cannot return to its caller.
-<a name="7.22.4.6" href="#7.22.4.6"><h5>7.22.4.6 The getenv function</h5></a>
+<h5><a name="7.22.4.6" href="#7.22.4.6">7.22.4.6 The getenv function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- char *getenv(const char *name);</pre>
+ char *getenv(const char *name);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The getenv function searches an environment list, provided by the host environment,
<p><small><a name="note293" href="#note293">293)</a> Many implementations provide non-standard functions that modify the environment list.
</small>
-<a name="7.22.4.7" href="#7.22.4.7"><h5>7.22.4.7 The quick_exit function</h5></a>
+<h5><a name="7.22.4.7" href="#7.22.4.7">7.22.4.7 The quick_exit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- _Noreturn void quick_exit(int status);</pre>
+ _Noreturn void quick_exit(int status);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The quick_exit function causes normal program termination to occur. No functions
other registered functions.
</small>
-<a name="7.22.4.8" href="#7.22.4.8"><h5>7.22.4.8 The system function</h5></a>
+<h5><a name="7.22.4.8" href="#7.22.4.8">7.22.4.8 The system function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- int system(const char *string);</pre>
+ int system(const char *string);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If string is a null pointer, the system function determines whether the host
command processor is available. If the argument is not a null pointer, and the system
function does return, it returns an implementation-defined value.
-<a name="7.22.5" href="#7.22.5"><h4>7.22.5 Searching and sorting utilities</h4></a>
+<h4><a name="7.22.5" href="#7.22.5">7.22.5 Searching and sorting utilities</a></h4>
<p><!--para 1 -->
These utilities make use of a comparison function to search or sort arrays of unspecified
type. Where an argument declared as size_t nmemb specifies the length of the array
<pre>
((char *)p - (char *)base) % size == 0
(char *)p >= (char *)base
- (char *)p < (char *)base + nmemb * size</pre>
+ (char *)p < (char *)base + nmemb * size
+</pre>
</small>
-<a name="7.22.5.1" href="#7.22.5.1"><h5>7.22.5.1 The bsearch function</h5></a>
+<h5><a name="7.22.5.1" href="#7.22.5.1">7.22.5.1 The bsearch function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
void *bsearch(const void *key, const void *base,
size_t nmemb, size_t size,
- int (*compar)(const void *, const void *));</pre>
+ int (*compar)(const void *, const void *));
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The bsearch function searches an array of nmemb objects, the initial element of which
<p><small><a name="note296" href="#note296">296)</a> In practice, the entire array is sorted according to the comparison function.
</small>
-<a name="7.22.5.2" href="#7.22.5.2"><h5>7.22.5.2 The qsort function</h5></a>
+<h5><a name="7.22.5.2" href="#7.22.5.2">7.22.5.2 The qsort function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
void qsort(void *base, size_t nmemb, size_t size,
- int (*compar)(const void *, const void *));</pre>
+ int (*compar)(const void *, const void *));
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The qsort function sorts an array of nmemb objects, the initial element of which is
<p><!--para 5 -->
The qsort function returns no value.
-<a name="7.22.6" href="#7.22.6"><h4>7.22.6 Integer arithmetic functions</h4></a>
+<h4><a name="7.22.6" href="#7.22.6">7.22.6 Integer arithmetic functions</a></h4>
-<a name="7.22.6.1" href="#7.22.6.1"><h5>7.22.6.1 The abs, labs and llabs functions</h5></a>
+<h5><a name="7.22.6.1" href="#7.22.6.1">7.22.6.1 The abs, labs and llabs functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
int abs(int j);
long int labs(long int j);
- long long int llabs(long long int j);</pre>
+ long long int llabs(long long int j);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The abs, labs, and llabs functions compute the absolute value of an integer j. If the
<p><small><a name="note297" href="#note297">297)</a> The absolute value of the most negative number cannot be represented in two's complement.
</small>
-<a name="7.22.6.2" href="#7.22.6.2"><h5>7.22.6.2 The div, ldiv, and lldiv functions</h5></a>
+<h5><a name="7.22.6.2" href="#7.22.6.2">7.22.6.2 The div, ldiv, and lldiv functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
div_t div(int numer, int denom);
ldiv_t ldiv(long int numer, long int denom);
- lldiv_t lldiv(long long int numer, long long int denom);</pre>
+ lldiv_t lldiv(long long int numer, long long int denom);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The div, ldiv, and lldiv, functions compute numer / denom and numer %
each of which has the same type as the arguments numer and denom. If either part of
the result cannot be represented, the behavior is undefined.
-<a name="7.22.7" href="#7.22.7"><h4>7.22.7 Multibyte/wide character conversion functions</h4></a>
+<h4><a name="7.22.7" href="#7.22.7">7.22.7 Multibyte/wide character conversion functions</a></h4>
<p><!--para 1 -->
The behavior of the multibyte character functions is affected by the LC_CTYPE category
of the current locale. For a state-dependent encoding, each function is placed into its
character codes, but are grouped with an adjacent multibyte character.
</small>
-<a name="7.22.7.1" href="#7.22.7.1"><h5>7.22.7.1 The mblen function</h5></a>
+<h5><a name="7.22.7.1" href="#7.22.7.1">7.22.7.1 The mblen function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- int mblen(const char *s, size_t n);</pre>
+ int mblen(const char *s, size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If s is not a null pointer, the mblen function determines the number of bytes contained
<!--page 375 -->
-<p><!--para 3 -->
<pre>
mbtowc((wchar_t *)0, (const char *)0, 0);
- mbtowc((wchar_t *)0, s, n);</pre>
+ mbtowc((wchar_t *)0, s, n);
+</pre>
+<p><!--para 3 -->
The implementation shall behave as if no library function calls the mblen function.
<h6>Returns</h6>
<p><!--para 4 -->
multibyte character).
<p><b> Forward references</b>: the mbtowc function (<a href="#7.22.7.2">7.22.7.2</a>).
-<a name="7.22.7.2" href="#7.22.7.2"><h5>7.22.7.2 The mbtowc function</h5></a>
+<h5><a name="7.22.7.2" href="#7.22.7.2">7.22.7.2 The mbtowc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
int mbtowc(wchar_t * restrict pwc,
const char * restrict s,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If s is not a null pointer, the mbtowc function inspects at most n bytes beginning with
macro.
<!--page 376 -->
-<a name="7.22.7.3" href="#7.22.7.3"><h5>7.22.7.3 The wctomb function</h5></a>
+<h5><a name="7.22.7.3" href="#7.22.7.3">7.22.7.3 The wctomb function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
- int wctomb(char *s, wchar_t wc);</pre>
+ int wctomb(char *s, wchar_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wctomb function determines the number of bytes needed to represent the multibyte
<p><!--para 5 -->
In no case will the value returned be greater than the value of the MB_CUR_MAX macro.
-<a name="7.22.8" href="#7.22.8"><h4>7.22.8 Multibyte/wide string conversion functions</h4></a>
+<h4><a name="7.22.8" href="#7.22.8">7.22.8 Multibyte/wide string conversion functions</a></h4>
<p><!--para 1 -->
The behavior of the multibyte string functions is affected by the LC_CTYPE category of
the current locale.
-<a name="7.22.8.1" href="#7.22.8.1"><h5>7.22.8.1 The mbstowcs function</h5></a>
+<h5><a name="7.22.8.1" href="#7.22.8.1">7.22.8.1 The mbstowcs function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
size_t mbstowcs(wchar_t * restrict pwcs,
const char * restrict s,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mbstowcs function converts a sequence of multibyte characters that begins in the
<p><small><a name="note299" href="#note299">299)</a> The array will not be null-terminated if the value returned is n.
</small>
-<a name="7.22.8.2" href="#7.22.8.2"><h5>7.22.8.2 The wcstombs function</h5></a>
+<h5><a name="7.22.8.2" href="#7.22.8.2">7.22.8.2 The wcstombs function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
size_t wcstombs(char * restrict s,
const wchar_t * restrict pwcs,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcstombs function converts a sequence of wide characters from the array pointed
If a wide character is encountered that does not correspond to a valid multibyte character,
the wcstombs function returns (size_t)(-1). Otherwise, the wcstombs function
returns the number of bytes modified, not including a terminating null character, if
- any.299)
+ any.<sup><a href="#note299"><b>299)</b></a></sup>
<!--page 378 -->
-<a name="7.23" href="#7.23"><h3>7.23 String handling <string.h></h3></a>
+<h3><a name="7.23" href="#7.23">7.23 String handling <string.h></a></h3>
-<a name="7.23.1" href="#7.23.1"><h4>7.23.1 String function conventions</h4></a>
+<h4><a name="7.23.1" href="#7.23.1">7.23.1 String function conventions</a></h4>
<p><!--para 1 -->
The header <a href="#7.23"><string.h></a> declares one type and several functions, and defines one
macro useful for manipulating arrays of character type and other objects treated as arrays
<p><small><a name="note300" href="#note300">300)</a> See ''future library directions'' (<a href="#7.30.11">7.30.11</a>).
</small>
-<a name="7.23.2" href="#7.23.2"><h4>7.23.2 Copying functions</h4></a>
+<h4><a name="7.23.2" href="#7.23.2">7.23.2 Copying functions</a></h4>
-<a name="7.23.2.1" href="#7.23.2.1"><h5>7.23.2.1 The memcpy function</h5></a>
+<h5><a name="7.23.2.1" href="#7.23.2.1">7.23.2.1 The memcpy function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
void *memcpy(void * restrict s1,
const void * restrict s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The memcpy function copies n characters from the object pointed to by s2 into the
<!--page 379 -->
-<a name="7.23.2.2" href="#7.23.2.2"><h5>7.23.2.2 The memmove function</h5></a>
+<h5><a name="7.23.2.2" href="#7.23.2.2">7.23.2.2 The memmove function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- void *memmove(void *s1, const void *s2, size_t n);</pre>
+ void *memmove(void *s1, const void *s2, size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The memmove function copies n characters from the object pointed to by s2 into the
<p><!--para 3 -->
The memmove function returns the value of s1.
-<a name="7.23.2.3" href="#7.23.2.3"><h5>7.23.2.3 The strcpy function</h5></a>
+<h5><a name="7.23.2.3" href="#7.23.2.3">7.23.2.3 The strcpy function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
char *strcpy(char * restrict s1,
- const char * restrict s2);</pre>
+ const char * restrict s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strcpy function copies the string pointed to by s2 (including the terminating null
<p><!--para 3 -->
The strcpy function returns the value of s1.
-<a name="7.23.2.4" href="#7.23.2.4"><h5>7.23.2.4 The strncpy function</h5></a>
+<h5><a name="7.23.2.4" href="#7.23.2.4">7.23.2.4 The strncpy function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
char *strncpy(char * restrict s1,
const char * restrict s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strncpy function copies not more than n characters (characters that follow a null
not be null-terminated.
</small>
-<a name="7.23.3" href="#7.23.3"><h4>7.23.3 Concatenation functions</h4></a>
+<h4><a name="7.23.3" href="#7.23.3">7.23.3 Concatenation functions</a></h4>
-<a name="7.23.3.1" href="#7.23.3.1"><h5>7.23.3.1 The strcat function</h5></a>
+<h5><a name="7.23.3.1" href="#7.23.3.1">7.23.3.1 The strcat function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
char *strcat(char * restrict s1,
- const char * restrict s2);</pre>
+ const char * restrict s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strcat function appends a copy of the string pointed to by s2 (including the
<p><!--para 3 -->
The strcat function returns the value of s1.
-<a name="7.23.3.2" href="#7.23.3.2"><h5>7.23.3.2 The strncat function</h5></a>
+<h5><a name="7.23.3.2" href="#7.23.3.2">7.23.3.2 The strncat function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
char *strncat(char * restrict s1,
const char * restrict s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strncat function appends not more than n characters (a null character and
strlen(s1)+n+1.
</small>
-<a name="7.23.4" href="#7.23.4"><h4>7.23.4 Comparison functions</h4></a>
+<h4><a name="7.23.4" href="#7.23.4">7.23.4 Comparison functions</a></h4>
<p><!--para 1 -->
The sign of a nonzero value returned by the comparison functions memcmp, strcmp,
and strncmp is determined by the sign of the difference between the values of the first
pair of characters (both interpreted as unsigned char) that differ in the objects being
compared.
-<a name="7.23.4.1" href="#7.23.4.1"><h5>7.23.4.1 The memcmp function</h5></a>
+<h5><a name="7.23.4.1" href="#7.23.4.1">7.23.4.1 The memcmp function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- int memcmp(const void *s1, const void *s2, size_t n);</pre>
+ int memcmp(const void *s1, const void *s2, size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The memcmp function compares the first n characters of the object pointed to by s1 to
comparison.
</small>
-<a name="7.23.4.2" href="#7.23.4.2"><h5>7.23.4.2 The strcmp function</h5></a>
+<h5><a name="7.23.4.2" href="#7.23.4.2">7.23.4.2 The strcmp function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- int strcmp(const char *s1, const char *s2);</pre>
+ int strcmp(const char *s1, const char *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strcmp function compares the string pointed to by s1 to the string pointed to by
<!--page 382 -->
pointed to by s2.
-<a name="7.23.4.3" href="#7.23.4.3"><h5>7.23.4.3 The strcoll function</h5></a>
+<h5><a name="7.23.4.3" href="#7.23.4.3">7.23.4.3 The strcoll function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- int strcoll(const char *s1, const char *s2);</pre>
+ int strcoll(const char *s1, const char *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strcoll function compares the string pointed to by s1 to the string pointed to by
accordingly as the string pointed to by s1 is greater than, equal to, or less than the string
pointed to by s2 when both are interpreted as appropriate to the current locale.
-<a name="7.23.4.4" href="#7.23.4.4"><h5>7.23.4.4 The strncmp function</h5></a>
+<h5><a name="7.23.4.4" href="#7.23.4.4">7.23.4.4 The strncmp function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- int strncmp(const char *s1, const char *s2, size_t n);</pre>
+ int strncmp(const char *s1, const char *s2, size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strncmp function compares not more than n characters (characters that follow a
accordingly as the possibly null-terminated array pointed to by s1 is greater than, equal
to, or less than the possibly null-terminated array pointed to by s2.
-<a name="7.23.4.5" href="#7.23.4.5"><h5>7.23.4.5 The strxfrm function</h5></a>
+<h5><a name="7.23.4.5" href="#7.23.4.5">7.23.4.5 The strxfrm function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
size_t strxfrm(char * restrict s1,
const char * restrict s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strxfrm function transforms the string pointed to by s2 and places the resulting
EXAMPLE The value of the following expression is the size of the array needed to hold the
transformation of the string pointed to by s.
<pre>
- 1 + strxfrm(NULL, s, 0)</pre>
+ 1 + strxfrm(NULL, s, 0)
+</pre>
-<a name="7.23.5" href="#7.23.5"><h4>7.23.5 Search functions</h4></a>
+<h4><a name="7.23.5" href="#7.23.5">7.23.5 Search functions</a></h4>
-<a name="7.23.5.1" href="#7.23.5.1"><h5>7.23.5.1 The memchr function</h5></a>
+<h5><a name="7.23.5.1" href="#7.23.5.1">7.23.5.1 The memchr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- void *memchr(const void *s, int c, size_t n);</pre>
+ void *memchr(const void *s, int c, size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The memchr function locates the first occurrence of c (converted to an unsigned
The memchr function returns a pointer to the located character, or a null pointer if the
character does not occur in the object.
-<a name="7.23.5.2" href="#7.23.5.2"><h5>7.23.5.2 The strchr function</h5></a>
+<h5><a name="7.23.5.2" href="#7.23.5.2">7.23.5.2 The strchr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- char *strchr(const char *s, int c);</pre>
+ char *strchr(const char *s, int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strchr function locates the first occurrence of c (converted to a char) in the
The strchr function returns a pointer to the located character, or a null pointer if the
character does not occur in the string.
-<a name="7.23.5.3" href="#7.23.5.3"><h5>7.23.5.3 The strcspn function</h5></a>
+<h5><a name="7.23.5.3" href="#7.23.5.3">7.23.5.3 The strcspn function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- size_t strcspn(const char *s1, const char *s2);</pre>
+ size_t strcspn(const char *s1, const char *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strcspn function computes the length of the maximum initial segment of the string
<p><!--para 3 -->
The strcspn function returns the length of the segment.
-<a name="7.23.5.4" href="#7.23.5.4"><h5>7.23.5.4 The strpbrk function</h5></a>
+<h5><a name="7.23.5.4" href="#7.23.5.4">7.23.5.4 The strpbrk function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- char *strpbrk(const char *s1, const char *s2);</pre>
+ char *strpbrk(const char *s1, const char *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strpbrk function locates the first occurrence in the string pointed to by s1 of any
The strpbrk function returns a pointer to the character, or a null pointer if no character
from s2 occurs in s1.
-<a name="7.23.5.5" href="#7.23.5.5"><h5>7.23.5.5 The strrchr function</h5></a>
+<h5><a name="7.23.5.5" href="#7.23.5.5">7.23.5.5 The strrchr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- char *strrchr(const char *s, int c);</pre>
+ char *strrchr(const char *s, int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strrchr function locates the last occurrence of c (converted to a char) in the
The strrchr function returns a pointer to the character, or a null pointer if c does not
occur in the string.
-<a name="7.23.5.6" href="#7.23.5.6"><h5>7.23.5.6 The strspn function</h5></a>
+<h5><a name="7.23.5.6" href="#7.23.5.6">7.23.5.6 The strspn function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- size_t strspn(const char *s1, const char *s2);</pre>
+ size_t strspn(const char *s1, const char *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strspn function computes the length of the maximum initial segment of the string
<p><!--para 3 -->
The strspn function returns the length of the segment.
-<a name="7.23.5.7" href="#7.23.5.7"><h5>7.23.5.7 The strstr function</h5></a>
+<h5><a name="7.23.5.7" href="#7.23.5.7">7.23.5.7 The strstr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- char *strstr(const char *s1, const char *s2);</pre>
+ char *strstr(const char *s1, const char *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strstr function locates the first occurrence in the string pointed to by s1 of the
The strstr function returns a pointer to the located string, or a null pointer if the string
is not found. If s2 points to a string with zero length, the function returns s1.
-<a name="7.23.5.8" href="#7.23.5.8"><h5>7.23.5.8 The strtok function</h5></a>
+<h5><a name="7.23.5.8" href="#7.23.5.8">7.23.5.8 The strtok function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
char *strtok(char * restrict s1,
- const char * restrict s2);</pre>
+ const char * restrict s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A sequence of calls to the strtok function breaks the string pointed to by s1 into a
t = strtok(str, "?"); // t points to the token "a"
t = strtok(NULL, ","); // t points to the token "??b"
t = strtok(NULL, "#,"); // t points to the token "c"
- t = strtok(NULL, "?"); // t is a null pointer</pre>
+ t = strtok(NULL, "?"); // t is a null pointer
+</pre>
-<a name="7.23.6" href="#7.23.6"><h4>7.23.6 Miscellaneous functions</h4></a>
+<h4><a name="7.23.6" href="#7.23.6">7.23.6 Miscellaneous functions</a></h4>
-<a name="7.23.6.1" href="#7.23.6.1"><h5>7.23.6.1 The memset function</h5></a>
+<h5><a name="7.23.6.1" href="#7.23.6.1">7.23.6.1 The memset function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- void *memset(void *s, int c, size_t n);</pre>
+ void *memset(void *s, int c, size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The memset function copies the value of c (converted to an unsigned char) into
The memset function returns the value of s.
<!--page 387 -->
-<a name="7.23.6.2" href="#7.23.6.2"><h5>7.23.6.2 The strerror function</h5></a>
+<h5><a name="7.23.6.2" href="#7.23.6.2">7.23.6.2 The strerror function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- char *strerror(int errnum);</pre>
+ char *strerror(int errnum);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strerror function maps the number in errnum to a message string. Typically,
specific. The array pointed to shall not be modified by the program, but may be
overwritten by a subsequent call to the strerror function.
-<a name="7.23.6.3" href="#7.23.6.3"><h5>7.23.6.3 The strlen function</h5></a>
+<h5><a name="7.23.6.3" href="#7.23.6.3">7.23.6.3 The strlen function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
- size_t strlen(const char *s);</pre>
+ size_t strlen(const char *s);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strlen function computes the length of the string pointed to by s.
character.
<!--page 388 -->
-<a name="7.24" href="#7.24"><h3>7.24 Type-generic math <tgmath.h></h3></a>
+<h3><a name="7.24" href="#7.24">7.24 Type-generic math <tgmath.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.24"><tgmath.h></a> includes the headers <a href="#7.12"><math.h></a> and <a href="#7.3"><complex.h></a> and
defines several type-generic macros.
log clog log
pow cpow pow
sqrt csqrt sqrt
- fabs cabs fabs</pre>
+ fabs cabs fabs
+</pre>
If at least one argument for a generic parameter is complex, then use of the macro invokes
a complex function; otherwise, use of the macro invokes a real function.
<p><!--para 5 -->
exp2 ilogb lround tgamma
expm1 ldexp nearbyint trunc
fdim lgamma nextafter
- floor llrint nexttoward</pre>
+ floor llrint nexttoward
+</pre>
If all arguments for generic parameters are real, then use of the macro invokes a real
function; otherwise, use of the macro results in undefined behavior.
<!--page 390 -->
function. These type-generic macros are:
<pre>
carg conj creal
- cimag cproj</pre>
+ cimag cproj
+</pre>
Use of the macro with any real or complex argument invokes a complex function.
<p><!--para 7 -->
EXAMPLE With the declarations
long double ld;
float complex fc;
double complex dc;
- long double complex ldc;</pre>
+ long double complex ldc;
+</pre>
functions invoked by use of type-generic macros are shown in the following table:
<!--page 391 -->
<pre>
cimag(ld) cimagl(ld)
fabs(fc) cabsf(fc)
carg(dc) carg(dc), the function
- cproj(ldc) cprojl(ldc)</pre>
+ cproj(ldc) cprojl(ldc)
+</pre>
<h6>footnotes</h6>
<p><small><a name="note304" href="#note304">304)</a> Like other function-like macros in Standard libraries, each type-generic macro can be suppressed to
the behavior is undefined.
</small>
-<a name="7.25" href="#7.25"><h3>7.25 Threads <threads.h></h3></a>
+<h3><a name="7.25" href="#7.25">7.25 Threads <threads.h></a></h3>
-<a name="7.25.1" href="#7.25.1"><h4>7.25.1 Introduction</h4></a>
+<h4><a name="7.25.1" href="#7.25.1">7.25.1 Introduction</a></h4>
<p><!--para 1 -->
The header <a href="#7.25"><threads.h></a> defines macros, and declares types, enumeration constants,
and functions that support multiple threads of execution.
<p><!--para 3 -->
The macros are
<pre>
- ONCE_FLAG_INIT</pre>
+ ONCE_FLAG_INIT
+</pre>
which expands to a value that can be used to initialize an object of type once_flag;
and
<pre>
- TSS_DTOR_ITERATIONS</pre>
+ TSS_DTOR_ITERATIONS
+</pre>
which expands to an integer constant expression representing the maximum number of
times that destructors will be called when a thread terminates.
<p><!--para 4 -->
The types are
<pre>
- cnd_t</pre>
+ cnd_t
+</pre>
which is a complete object type that holds an identifier for a condition variable;
<pre>
- thrd_t</pre>
+ thrd_t
+</pre>
which is a complete object type that holds an identifier for a thread;
<pre>
- tss_t</pre>
+ tss_t
+</pre>
which is a complete object type that holds an identifier for a thread-specific storage
pointer;
<pre>
- mtx_t</pre>
+ mtx_t
+</pre>
which is a complete object type that holds an identifier for a mutex;
<pre>
- tss_dtor_t</pre>
+ tss_dtor_t
+</pre>
which is the function pointer type void (*)(void*), used for a destructor for a
thread-specific storage pointer;
<pre>
- thrd_start_t</pre>
+ thrd_start_t
+</pre>
which is the function pointer type int (*)(void*) that is passed to thrd_create
to create a new thread;
<pre>
- once_flag</pre>
+ once_flag
+</pre>
which is a complete object type that holds a flag for use by call_once; and
<!--page 392 -->
<pre>
- xtime</pre>
+ xtime
+</pre>
which is a structure type that holds a time specified in seconds and nanoseconds. The
structure shall contain at least the following members, in any order.
-<p><!--para 5 -->
<pre>
time_t sec;
- long nsec;</pre>
+ long nsec;
+</pre>
+<p><!--para 5 -->
The enumeration constants are
<pre>
- mtx_plain</pre>
+ mtx_plain
+</pre>
which is passed to mtx_init to create a mutex object that supports neither timeout nor
test and return;
<pre>
- mtx_recursive</pre>
+ mtx_recursive
+</pre>
which is passed to mtx_init to create a mutex object that supports recursive locking;
<pre>
- mtx_timed</pre>
+ mtx_timed
+</pre>
which is passed to mtx_init to create a mutex object that supports timeout;
<pre>
- mtx_try</pre>
+ mtx_try
+</pre>
which is passed to mtx_init to create a mutex object that supports test and return;
<pre>
- thrd_timeout</pre>
+ thrd_timeout
+</pre>
which is returned by a timed wait function to indicate that the time specified in the call
was reached without acquiring the requested resource;
<pre>
- thrd_success</pre>
+ thrd_success
+</pre>
which is returned by a function to indicate that the requested operation succeeded;
<pre>
- thrd_busy</pre>
+ thrd_busy
+</pre>
which is returned by a function to indicate that the requested operation failed because a
resource requested by a test and return function is already in use;
<pre>
- thrd_error</pre>
+ thrd_error
+</pre>
which is returned by a function to indicate that the requested operation failed; and
<pre>
- thrd_nomem</pre>
+ thrd_nomem
+</pre>
which is returned by a function to indicate that the requested operation failed because it
was unable to allocate memory.
<!--page 393 -->
-<a name="7.25.2" href="#7.25.2"><h4>7.25.2 Initialization functions</h4></a>
+<h4><a name="7.25.2" href="#7.25.2">7.25.2 Initialization functions</a></h4>
-<a name="7.25.2.1" href="#7.25.2.1"><h5>7.25.2.1 The call_once function</h5></a>
+<h5><a name="7.25.2.1" href="#7.25.2.1">7.25.2.1 The call_once function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- void call_once(once_flag *flag, void (*func)(void));</pre>
+ void call_once(once_flag *flag, void (*func)(void));
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The call_once function uses the once_flag pointed to by flag to ensure that
<p><!--para 3 -->
The call_once function returns no value.
-<a name="7.25.3" href="#7.25.3"><h4>7.25.3 Condition variable functions</h4></a>
+<h4><a name="7.25.3" href="#7.25.3">7.25.3 Condition variable functions</a></h4>
-<a name="7.25.3.1" href="#7.25.3.1"><h5>7.25.3.1 The cnd_broadcast function</h5></a>
+<h5><a name="7.25.3.1" href="#7.25.3.1">7.25.3.1 The cnd_broadcast function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int cnd_broadcast(cnd_t *cond);</pre>
+ int cnd_broadcast(cnd_t *cond);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cnd_broadcast function unblocks all of the threads that are blocked on the
The cnd_broadcast function returns thrd_success on success, or thrd_error
if the request could not be honored.
-<a name="7.25.3.2" href="#7.25.3.2"><h5>7.25.3.2 The cnd_destroy function</h5></a>
+<h5><a name="7.25.3.2" href="#7.25.3.2">7.25.3.2 The cnd_destroy function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- void cnd_destroy(cnd_t *cond);</pre>
+ void cnd_destroy(cnd_t *cond);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cnd_destroy function releases all resources used by the condition variable
<p><!--para 3 -->
The cnd_destroy function returns no value.
-<a name="7.25.3.3" href="#7.25.3.3"><h5>7.25.3.3 The cnd_init function</h5></a>
+<h5><a name="7.25.3.3" href="#7.25.3.3">7.25.3.3 The cnd_init function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int cnd_init(cnd_t *cond);</pre>
+ int cnd_init(cnd_t *cond);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cnd_init function creates a condition variable. If it succeeds it sets the variable
memory could be allocated for the newly created condition, or thrd_error if the
request could not be honored.
-<a name="7.25.3.4" href="#7.25.3.4"><h5>7.25.3.4 The cnd_signal function</h5></a>
+<h5><a name="7.25.3.4" href="#7.25.3.4">7.25.3.4 The cnd_signal function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int cnd_signal(cnd_t *cond);</pre>
+ int cnd_signal(cnd_t *cond);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cnd_signal function unblocks one of the threads that are blocked on the
The cnd_signal function returns thrd_success on success or thrd_error if
the request could not be honored.
-<a name="7.25.3.5" href="#7.25.3.5"><h5>7.25.3.5 The cnd_timedwait function</h5></a>
+<h5><a name="7.25.3.5" href="#7.25.3.5">7.25.3.5 The cnd_timedwait function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<!--page 395 -->
<pre>
#include <a href="#7.25"><threads.h></a>
int cnd_timedwait(cnd_t *cond, mtx_t *mtx,
- const xtime *xt);</pre>
+ const xtime *xt);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cnd_timedwait function atomically unlocks the mutex pointed to by mtx and
thrd_timeout if the time specified in the call was reached without acquiring the
requested resource, or thrd_error if the request could not be honored.
-<a name="7.25.3.6" href="#7.25.3.6"><h5>7.25.3.6 The cnd_wait function</h5></a>
+<h5><a name="7.25.3.6" href="#7.25.3.6">7.25.3.6 The cnd_wait function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int cnd_wait(cnd_t *cond, mtx_t *mtx);</pre>
+ int cnd_wait(cnd_t *cond, mtx_t *mtx);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The cnd_wait function atomically unlocks the mutex pointed to by mtx and endeavors
The cnd_wait function returns thrd_success on success or thrd_error if the
request could not be honored.
-<a name="7.25.4" href="#7.25.4"><h4>7.25.4 Mutex functions</h4></a>
+<h4><a name="7.25.4" href="#7.25.4">7.25.4 Mutex functions</a></h4>
-<a name="7.25.4.1" href="#7.25.4.1"><h5>7.25.4.1 The mtx_destroy function</h5></a>
+<h5><a name="7.25.4.1" href="#7.25.4.1">7.25.4.1 The mtx_destroy function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- void mtx_destroy(mtx_t *mtx);</pre>
+ void mtx_destroy(mtx_t *mtx);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mtx_destroy function releases any resources used by the mutex pointed to by
<p><!--para 3 -->
The mtx_destroy function returns no value.
-<a name="7.25.4.2" href="#7.25.4.2"><h5>7.25.4.2 The mtx_init function</h5></a>
+<h5><a name="7.25.4.2" href="#7.25.4.2">7.25.4.2 The mtx_init function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int mtx_init(mtx_t *mtx, int type);</pre>
+ int mtx_init(mtx_t *mtx, int type);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mtx_init function creates a mutex object with properties indicated by type,
The mtx_init function returns thrd_success on success, or thrd_error if the
request could not be honored.
-<a name="7.25.4.3" href="#7.25.4.3"><h5>7.25.4.3 The mtx_lock function</h5></a>
+<h5><a name="7.25.4.3" href="#7.25.4.3">7.25.4.3 The mtx_lock function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int mtx_lock(mtx_t *mtx);</pre>
+ int mtx_lock(mtx_t *mtx);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mtx_lock function blocks until it locks the mutex pointed to by mtx. If the mutex
honored.
<!--page 397 -->
-<a name="7.25.4.4" href="#7.25.4.4"><h5>7.25.4.4 The mtx_timedlock function</h5></a>
+<h5><a name="7.25.4.4" href="#7.25.4.4">7.25.4.4 The mtx_timedlock function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int mtx_timedlock(mtx_t *mtx, const xtime *xt);</pre>
+ int mtx_timedlock(mtx_t *mtx, const xtime *xt);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mtx_timedlock function endeavors to block until it locks the mutex pointed to by
reached without acquiring the requested resource, or thrd_error if the request could
not be honored.
-<a name="7.25.4.5" href="#7.25.4.5"><h5>7.25.4.5 The mtx_trylock function</h5></a>
+<h5><a name="7.25.4.5" href="#7.25.4.5">7.25.4.5 The mtx_trylock function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int mtx_trylock(mtx_t *mtx);</pre>
+ int mtx_trylock(mtx_t *mtx);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mtx_trylock function endeavors to lock the mutex pointed to by mtx. The
the resource requested is already in use, or thrd_error if the request could not be
honored.
-<a name="7.25.4.6" href="#7.25.4.6"><h5>7.25.4.6 The mtx_unlock function</h5></a>
+<h5><a name="7.25.4.6" href="#7.25.4.6">7.25.4.6 The mtx_unlock function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int mtx_unlock(mtx_t *mtx);</pre>
+ int mtx_unlock(mtx_t *mtx);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mtx_unlock function unlocks the mutex pointed to by mtx. The mutex pointed to
The mtx_unlock function returns thrd_success on success or thrd_error if
the request could not be honored.
-<a name="7.25.5" href="#7.25.5"><h4>7.25.5 Thread functions</h4></a>
+<h4><a name="7.25.5" href="#7.25.5">7.25.5 Thread functions</a></h4>
-<a name="7.25.5.1" href="#7.25.5.1"><h5>7.25.5.1 The thrd_create function</h5></a>
+<h5><a name="7.25.5.1" href="#7.25.5.1">7.25.5.1 The thrd_create function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
int thrd_create(thrd_t *thr, thrd_start_t func,
- void *arg);</pre>
+ void *arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The thrd_create function creates a new thread executing func(arg). If the
no memory could be allocated for the thread requested, or thrd_error if the request
could not be honored.
-<a name="7.25.5.2" href="#7.25.5.2"><h5>7.25.5.2 The thrd_current function</h5></a>
+<h5><a name="7.25.5.2" href="#7.25.5.2">7.25.5.2 The thrd_current function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- thrd_t thrd_current(void);</pre>
+ thrd_t thrd_current(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The thrd_current function identifies the thread that called it.
<p><!--para 3 -->
The thrd_current function returns the identifier of the thread that called it.
-<a name="7.25.5.3" href="#7.25.5.3"><h5>7.25.5.3 The thrd_detach function</h5></a>
+<h5><a name="7.25.5.3" href="#7.25.5.3">7.25.5.3 The thrd_detach function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<!--page 399 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int thrd_detach(thrd_t thr);</pre>
+ int thrd_detach(thrd_t thr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The thrd_detach function tells the operating system to dispose of any resources
The thrd_detach function returns thrd_success on success or thrd_error if
the request could not be honored.
-<a name="7.25.5.4" href="#7.25.5.4"><h5>7.25.5.4 The thrd_equal function</h5></a>
+<h5><a name="7.25.5.4" href="#7.25.5.4">7.25.5.4 The thrd_equal function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int thrd_equal(thrd_t thr0, thrd_t thr1);</pre>
+ int thrd_equal(thrd_t thr0, thrd_t thr1);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The thrd_equal function will determine whether the thread identified by thr0 refers
The thrd_equal function returns zero if the thread thr0 and the thread thr1 refer to
different threads. Otherwise the thrd_equal function returns a nonzero value.
-<a name="7.25.5.5" href="#7.25.5.5"><h5>7.25.5.5 The thrd_exit function</h5></a>
+<h5><a name="7.25.5.5" href="#7.25.5.5">7.25.5.5 The thrd_exit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- void thrd_exit(int res);</pre>
+ void thrd_exit(int res);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The thrd_exit function terminates execution of the calling thread and sets its result
<p><!--para 3 -->
The thrd_exit function returns no value.
-<a name="7.25.5.6" href="#7.25.5.6"><h5>7.25.5.6 The thrd_join function</h5></a>
+<h5><a name="7.25.5.6" href="#7.25.5.6">7.25.5.6 The thrd_join function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int thrd_join(thrd_t thr, int *res);</pre>
+ int thrd_join(thrd_t thr, int *res);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The thrd_join function joins the thread identified by thr with the current thread by
The thrd_join function returns thrd_success on success or thrd_error if the
request could not be honored.
-<a name="7.25.5.7" href="#7.25.5.7"><h5>7.25.5.7 The thrd_sleep function</h5></a>
+<h5><a name="7.25.5.7" href="#7.25.5.7">7.25.5.7 The thrd_sleep function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- void thrd_sleep(const xtime *xt);</pre>
+ void thrd_sleep(const xtime *xt);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The thrd_sleep function suspends execution of the calling thread until after the time
<p><!--para 3 -->
The thrd_sleep function returns no value.
-<a name="7.25.5.8" href="#7.25.5.8"><h5>7.25.5.8 The thrd_yield function</h5></a>
+<h5><a name="7.25.5.8" href="#7.25.5.8">7.25.5.8 The thrd_yield function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- void thrd_yield(void);</pre>
+ void thrd_yield(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The thrd_yield function endeavors to permit other threads to run, even if the current
<p><!--para 3 -->
The thrd_yield function returns no value.
-<a name="7.25.6" href="#7.25.6"><h4>7.25.6 Thread-specific storage functions</h4></a>
+<h4><a name="7.25.6" href="#7.25.6">7.25.6 Thread-specific storage functions</a></h4>
-<a name="7.25.6.1" href="#7.25.6.1"><h5>7.25.6.1 The tss_create function</h5></a>
+<h5><a name="7.25.6.1" href="#7.25.6.1">7.25.6.1 The tss_create function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int tss_create(tss_t *key, tss_dtor_t dtor);</pre>
+ int tss_create(tss_t *key, tss_dtor_t dtor);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tss_create function creates a thread-specific storage pointer with destructor
thrd_success; otherwise, thrd_error is returned and the thread-specific storage
pointed to by key is set to an undefined value.
-<a name="7.25.6.2" href="#7.25.6.2"><h5>7.25.6.2 The tss_delete function</h5></a>
+<h5><a name="7.25.6.2" href="#7.25.6.2">7.25.6.2 The tss_delete function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- void tss_delete(tss_t key);</pre>
+ void tss_delete(tss_t key);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tss_delete function releases any resources used by the thread-specific storage
<p><!--para 3 -->
The tss_delete function returns no value.
-<a name="7.25.6.3" href="#7.25.6.3"><h5>7.25.6.3 The tss_get function</h5></a>
+<h5><a name="7.25.6.3" href="#7.25.6.3">7.25.6.3 The tss_get function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- void *tss_get(tss_t key);</pre>
+ void *tss_get(tss_t key);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tss_get function returns the value for the current thread held in the thread-specific
The tss_get function returns the value for the current thread if successful, or zero if
unsuccessful.
-<a name="7.25.6.4" href="#7.25.6.4"><h5>7.25.6.4 The tss_set function</h5></a>
+<h5><a name="7.25.6.4" href="#7.25.6.4">7.25.6.4 The tss_set function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int tss_set(tss_t key, void *val);</pre>
+ int tss_set(tss_t key, void *val);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The tss_set function sets the value for the current thread held in the thread-specific
The tss_set function returns thrd_success on success or thrd_error if the
request could not be honored.
-<a name="7.25.7" href="#7.25.7"><h4>7.25.7 Time functions</h4></a>
+<h4><a name="7.25.7" href="#7.25.7">7.25.7 Time functions</a></h4>
-<a name="7.25.7.1" href="#7.25.7.1"><h5>7.25.7.1 The xtime_get function</h5></a>
+<h5><a name="7.25.7.1" href="#7.25.7.1">7.25.7.1 The xtime_get function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.25"><threads.h></a>
- int xtime_get(xtime *xt, int base);</pre>
+ int xtime_get(xtime *xt, int base);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The xtime_get function sets the xtime object pointed to by xt to hold the current
xtime object is system dependent.
</small>
-<a name="7.26" href="#7.26"><h3>7.26 Date and time <time.h></h3></a>
+<h3><a name="7.26" href="#7.26">7.26 Date and time <time.h></a></h3>
-<a name="7.26.1" href="#7.26.1"><h4>7.26.1 Components of time</h4></a>
+<h4><a name="7.26.1" href="#7.26.1">7.26.1 Components of time</a></h4>
<p><!--para 1 -->
The header <a href="#7.26"><time.h></a> defines two macros, and declares several types and functions for
manipulating time. Many functions deal with a calendar time that represents the current
<p><!--para 2 -->
The macros defined are NULL (described in <a href="#7.19">7.19</a>); and
<pre>
- CLOCKS_PER_SEC</pre>
+ CLOCKS_PER_SEC
+</pre>
which expands to an expression with type clock_t (described below) that is the
number per second of the value returned by the clock function.
<p><!--para 3 -->
The types declared are size_t (described in <a href="#7.19">7.19</a>);
<pre>
- clock_t</pre>
+ clock_t
+</pre>
and
<pre>
- time_t</pre>
+ time_t
+</pre>
which are arithmetic types capable of representing times; and
<pre>
- struct tm</pre>
+ struct tm
+</pre>
which holds the components of a calendar time, called the broken-down time.
<p><!--para 4 -->
The range and precision of times representable in clock_t and time_t are
int tm_year; // years since 1900
int tm_wday; // days since Sunday -- [0, 6]
int tm_yday; // days since January 1 -- [0, 365]
- int tm_isdst; // Daylight Saving Time flag</pre>
+ int tm_isdst; // Daylight Saving Time flag
+</pre>
<p><small><a name="note307" href="#note307">307)</a> The range [0, 60] for tm_sec allows for a positive leap second.
</small>
-<a name="7.26.2" href="#7.26.2"><h4>7.26.2 Time manipulation functions</h4></a>
+<h4><a name="7.26.2" href="#7.26.2">7.26.2 Time manipulation functions</a></h4>
-<a name="7.26.2.1" href="#7.26.2.1"><h5>7.26.2.1 The clock function</h5></a>
+<h5><a name="7.26.2.1" href="#7.26.2.1">7.26.2.1 The clock function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.26"><time.h></a>
- clock_t clock(void);</pre>
+ clock_t clock(void);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The clock function determines the processor time used.
the program and its return value subtracted from the value returned by subsequent calls.
</small>
-<a name="7.26.2.2" href="#7.26.2.2"><h5>7.26.2.2 The difftime function</h5></a>
+<h5><a name="7.26.2.2" href="#7.26.2.2">7.26.2.2 The difftime function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.26"><time.h></a>
- double difftime(time_t time1, time_t time0);</pre>
+ double difftime(time_t time1, time_t time0);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The difftime function computes the difference between two calendar times: time1 -
<!--page 405 -->
-<a name="7.26.2.3" href="#7.26.2.3"><h5>7.26.2.3 The mktime function</h5></a>
+<h5><a name="7.26.2.3" href="#7.26.2.3">7.26.2.3 The mktime function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.26"><time.h></a>
- time_t mktime(struct tm *timeptr);</pre>
+ time_t mktime(struct tm *timeptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mktime function converts the broken-down time, expressed as local time, in the
"Thursday", "Friday", "Saturday", "-unknown-"
};
struct tm time_str;
- /* ... */</pre>
+ /* ... */
+</pre>
time_str.tm_isdst = -1;
if (mktime(&time_str) == (time_t)(-1))
time_str.tm_wday = 7;
- printf("%s\n", wday[time_str.tm_wday]);</pre>
+ printf("%s\n", wday[time_str.tm_wday]);
+</pre>
<h6>footnotes</h6>
causes it to attempt to determine whether Daylight Saving Time is in effect for the specified time.
</small>
-<a name="7.26.2.4" href="#7.26.2.4"><h5>7.26.2.4 The time function</h5></a>
+<h5><a name="7.26.2.4" href="#7.26.2.4">7.26.2.4 The time function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.26"><time.h></a>
- time_t time(time_t *timer);</pre>
+ time_t time(time_t *timer);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The time function determines the current calendar time. The encoding of the value is
available. If timer is not a null pointer, the return value is also assigned to the object it
points to.
-<a name="7.26.3" href="#7.26.3"><h4>7.26.3 Time conversion functions</h4></a>
+<h4><a name="7.26.3" href="#7.26.3">7.26.3 Time conversion functions</a></h4>
<p><!--para 1 -->
Except for the strftime function, these functions each return a pointer to one of two
types of static objects: a broken-down time structure or an array of char. Execution of
previous call to any of them and the functions are not required to avoid data races. The
implementation shall behave as if no other library functions call these functions.
-<a name="7.26.3.1" href="#7.26.3.1"><h5>7.26.3.1 The asctime function</h5></a>
+<h5><a name="7.26.3.1" href="#7.26.3.1">7.26.3.1 The asctime function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.26"><time.h></a>
- char *asctime(const struct tm *timeptr);</pre>
+ char *asctime(const struct tm *timeptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The asctime function converts the broken-down time in the structure pointed to by
timeptr into a string in the form
<!--page 407 -->
<pre>
- Sun Sep 16 01:03:52 1973\n\0</pre>
+ Sun Sep 16 01:03:52 1973\n\0
+</pre>
using the equivalent of the following algorithm.
char *asctime(const struct tm *timeptr)
{
timeptr->tm_mday, timeptr->tm_hour,
timeptr->tm_min, timeptr->tm_sec,
1900 + timeptr->tm_year);
- return result;</pre>
+ return result;
+</pre>
}
<p><!--para 3 -->
If any of the fields of the broken-down time contain values that are outside their normal
<p><small><a name="note310" href="#note310">310)</a> See <a href="#7.26.1">7.26.1</a>.
</small>
-<a name="7.26.3.2" href="#7.26.3.2"><h5>7.26.3.2 The ctime function</h5></a>
+<h5><a name="7.26.3.2" href="#7.26.3.2">7.26.3.2 The ctime function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.26"><time.h></a>
- char *ctime(const time_t *timer);</pre>
+ char *ctime(const time_t *timer);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ctime function converts the calendar time pointed to by timer to local time in the
form of a string. It is equivalent to
<pre>
- asctime(localtime(timer))</pre>
+ asctime(localtime(timer))
+</pre>
broken-down time as argument.
<p><b> Forward references</b>: the localtime function (<a href="#7.26.3.4">7.26.3.4</a>).
-<a name="7.26.3.3" href="#7.26.3.3"><h5>7.26.3.3 The gmtime function</h5></a>
+<h5><a name="7.26.3.3" href="#7.26.3.3">7.26.3.3 The gmtime function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.26"><time.h></a>
- struct tm *gmtime(const time_t *timer);</pre>
+ struct tm *gmtime(const time_t *timer);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The gmtime function converts the calendar time pointed to by timer into a broken-
The gmtime function returns a pointer to the broken-down time, or a null pointer if the
specified time cannot be converted to UTC.
-<a name="7.26.3.4" href="#7.26.3.4"><h5>7.26.3.4 The localtime function</h5></a>
+<h5><a name="7.26.3.4" href="#7.26.3.4">7.26.3.4 The localtime function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.26"><time.h></a>
- struct tm *localtime(const time_t *timer);</pre>
+ struct tm *localtime(const time_t *timer);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The localtime function converts the calendar time pointed to by timer into a
The localtime function returns a pointer to the broken-down time, or a null pointer if
the specified time cannot be converted to local time.
-<a name="7.26.3.5" href="#7.26.3.5"><h5>7.26.3.5 The strftime function</h5></a>
+<h5><a name="7.26.3.5" href="#7.26.3.5">7.26.3.5 The strftime function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<!--page 409 -->
size_t strftime(char * restrict s,
size_t maxsize,
const char * restrict format,
- const struct tm * restrict timeptr);</pre>
+ const struct tm * restrict timeptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strftime function places characters into the array pointed to by s as controlled by
%B is replaced by the locale's full month name. [tm_mon]
%c is replaced by the locale's appropriate date and time representation. [all specified
<pre>
- in <a href="#7.26.1">7.26.1</a>]</pre>
+ in <a href="#7.26.1">7.26.1</a>]
+</pre>
%C is replaced by the year divided by 100 and truncated to an integer, as a decimal
<pre>
- number (00-99). [tm_year]</pre>
+ number (00-99). [tm_year]
+</pre>
%d is replaced by the day of the month as a decimal number (01-31). [tm_mday]
%D is equivalent to ''%m/%d/%y''. [tm_mon, tm_mday, tm_year]
%e is replaced by the day of the month as a decimal number (1-31); a single digit is
<pre>
- preceded by a space. [tm_mday]</pre>
+ preceded by a space. [tm_mday]
+</pre>
%F is equivalent to ''%Y-%m-%d'' (the ISO 8601 date format). [tm_year, tm_mon,
<pre>
- tm_mday]</pre>
+ tm_mday]
+</pre>
%g is replaced by the last 2 digits of the week-based year (see below) as a decimal
<pre>
- number (00-99). [tm_year, tm_wday, tm_yday]</pre>
+ number (00-99). [tm_year, tm_wday, tm_yday]
+</pre>
%G is replaced by the week-based year (see below) as a decimal number (e.g., 1997).
<pre>
- [tm_year, tm_wday, tm_yday]</pre>
+ [tm_year, tm_wday, tm_yday]
+</pre>
%h is equivalent to ''%b''. [tm_mon]
%H is replaced by the hour (24-hour clock) as a decimal number (00-23). [tm_hour]
%I is replaced by the hour (12-hour clock) as a decimal number (01-12). [tm_hour]
<!--page 410 -->
%p is replaced by the locale's equivalent of the AM/PM designations associated with a
<pre>
- 12-hour clock. [tm_hour]</pre>
+ 12-hour clock. [tm_hour]
+</pre>
%r is replaced by the locale's 12-hour clock time. [tm_hour, tm_min, tm_sec]
%R is equivalent to ''%H:%M''. [tm_hour, tm_min]
%S is replaced by the second as a decimal number (00-60). [tm_sec]
%t is replaced by a horizontal-tab character.
%T is equivalent to ''%H:%M:%S'' (the ISO 8601 time format). [tm_hour, tm_min,
<pre>
- tm_sec]</pre>
+ tm_sec]
+</pre>
%u is replaced by the ISO 8601 weekday as a decimal number (1-7), where Monday
<pre>
- is 1. [tm_wday]</pre>
+ is 1. [tm_wday]
+</pre>
%U is replaced by the week number of the year (the first Sunday as the first day of week
<pre>
- 1) as a decimal number (00-53). [tm_year, tm_wday, tm_yday]</pre>
+ 1) as a decimal number (00-53). [tm_year, tm_wday, tm_yday]
+</pre>
%V is replaced by the ISO 8601 week number (see below) as a decimal number
<pre>
- (01-53). [tm_year, tm_wday, tm_yday]</pre>
+ (01-53). [tm_year, tm_wday, tm_yday]
+</pre>
%w is replaced by the weekday as a decimal number (0-6), where Sunday is 0.
<pre>
- [tm_wday]</pre>
+ [tm_wday]
+</pre>
%W is replaced by the week number of the year (the first Monday as the first day of
<pre>
- week 1) as a decimal number (00-53). [tm_year, tm_wday, tm_yday]</pre>
+ week 1) as a decimal number (00-53). [tm_year, tm_wday, tm_yday]
+</pre>
%x is replaced by the locale's appropriate date representation. [all specified in <a href="#7.26.1">7.26.1</a>]
%X is replaced by the locale's appropriate time representation. [all specified in <a href="#7.26.1">7.26.1</a>]
%y is replaced by the last 2 digits of the year as a decimal number (00-99).
<pre>
- [tm_year]</pre>
+ [tm_year]
+</pre>
%Y is replaced by the year as a decimal number (e.g., 1997). [tm_year]
%z is replaced by the offset from UTC in the ISO 8601 format ''-0430'' (meaning 4
<pre>
hours 30 minutes behind UTC, west of Greenwich), or by no characters if no time
- zone is determinable. [tm_isdst]</pre>
+ zone is determinable. [tm_isdst]
+</pre>
%Z is replaced by the locale's time zone name or abbreviation, or by no characters if no
<pre>
- time zone is determinable. [tm_isdst]</pre>
+ time zone is determinable. [tm_isdst]
+</pre>
%% is replaced by %.
<p><!--para 4 -->
Some conversion specifiers can be modified by the inclusion of an E or O modifier
%Ec is replaced by the locale's alternative date and time representation.
%EC is replaced by the name of the base year (period) in the locale's alternative
<pre>
- representation.</pre>
+ representation.
+</pre>
%Ex is replaced by the locale's alternative date representation.
%EX is replaced by the locale's alternative time representation.
%Ey is replaced by the offset from %EC (year only) in the locale's alternative
<pre>
- representation.</pre>
+ representation.
+</pre>
%EY is replaced by the locale's full alternative year representation.
<!--page 411 -->
%Od is replaced by the day of the month, using the locale's alternative numeric symbols
<pre>
(filled as needed with leading zeros, or with leading spaces if there is no alternative
- symbol for zero).</pre>
+ symbol for zero).
+</pre>
%Oe is replaced by the day of the month, using the locale's alternative numeric symbols
<pre>
- (filled as needed with leading spaces).</pre>
+ (filled as needed with leading spaces).
+</pre>
%OH is replaced by the hour (24-hour clock), using the locale's alternative numeric
<pre>
- symbols.</pre>
+ symbols.
+</pre>
%OI is replaced by the hour (12-hour clock), using the locale's alternative numeric
<pre>
- symbols.</pre>
+ symbols.
+</pre>
%Om is replaced by the month, using the locale's alternative numeric symbols.
%OM is replaced by the minutes, using the locale's alternative numeric symbols.
%OS is replaced by the seconds, using the locale's alternative numeric symbols.
%Ou is replaced by the ISO 8601 weekday as a number in the locale's alternative
<pre>
- representation, where Monday is 1.</pre>
+ representation, where Monday is 1.
+</pre>
%OU is replaced by the week number, using the locale's alternative numeric symbols.
%OV is replaced by the ISO 8601 week number, using the locale's alternative numeric
<pre>
- symbols.</pre>
+ symbols.
+</pre>
%Ow is replaced by the weekday as a number, using the locale's alternative numeric
<pre>
- symbols.</pre>
+ symbols.
+</pre>
%OW is replaced by the week number of the year, using the locale's alternative numeric
<pre>
- symbols.</pre>
+ symbols.
+</pre>
%Oy is replaced by the last 2 digits of the year, using the locale's alternative numeric
-<p><!--para 5 -->
<pre>
- symbols.</pre>
+ symbols.
+</pre>
+<p><!--para 5 -->
%g, %G, and %V give values according to the ISO 8601 week-based year. In this system,
weeks begin on a Monday and week 1 of the year is the week that includes January 4th,
which is also the week that includes the first Thursday of the year, and is also the first
zero is returned and the contents of the array are indeterminate.
<!--page 413 -->
-<a name="7.27" href="#7.27"><h3>7.27 Unicode utilities <uchar.h></h3></a>
+<h3><a name="7.27" href="#7.27">7.27 Unicode utilities <uchar.h></a></h3>
<p><!--para 1 -->
The header <a href="#7.27"><uchar.h></a> declares types and functions for manipulating Unicode
characters.
The types declared are mbstate_t (described in <a href="#7.29.1">7.29.1</a>) and size_t (described in
<a href="#7.19">7.19</a>);
<pre>
- char16_t</pre>
+ char16_t
+</pre>
which is an unsigned integer type used for 16-bit characters and is the same type as
uint_least16_t (described in <a href="#7.20.1.2">7.20.1.2</a>); and
<pre>
- char32_t</pre>
+ char32_t
+</pre>
which is an unsigned integer type used for 32-bit characters and is the same type as
uint_least32_t (also described in <a href="#7.20.1.2">7.20.1.2</a>).
-<a name="7.27.1" href="#7.27.1"><h4>7.27.1 Restartable multibyte/wide character conversion functions</h4></a>
+<h4><a name="7.27.1" href="#7.27.1">7.27.1 Restartable multibyte/wide character conversion functions</a></h4>
<p><!--para 1 -->
These functions have a parameter, ps, of type pointer to mbstate_t that points to an
object that can completely describe the current conversion state of the associated
to avoid data races in this case. The implementation behaves as if no library function
calls these functions with a null pointer for ps.
-<a name="7.27.1.1" href="#7.27.1.1"><h5>7.27.1.1 The mbrtoc16 function</h5></a>
+<h5><a name="7.27.1.1" href="#7.27.1.1">7.27.1.1 The mbrtoc16 function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.27"><uchar.h></a>
size_t mbrtoc16(char16_t * restrict pc16,
const char * restrict s, size_t n,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If s is a null pointer, the mbrtoc16 function is equivalent to the call:
<pre>
- mbrtoc16(NULL, "", 1, ps)</pre>
+ mbrtoc16(NULL, "", 1, ps)
+</pre>
In this case, the values of the parameters pc16 and n are ignored.
<p><!--para 3 -->
If s is not a null pointer, the mbrtoc16 function inspects at most n bytes beginning with
conversion state):
0 if the next n or fewer bytes complete the multibyte character that
<pre>
- corresponds to the null wide character (which is the value stored).</pre>
+ corresponds to the null wide character (which is the value stored).
+</pre>
between 1 and n inclusive if the next n or fewer bytes complete a valid multibyte
<pre>
character (which is the value stored); the value returned is the number
- of bytes that complete the multibyte character.</pre>
+ of bytes that complete the multibyte character.
+</pre>
(size_t)(-3) if the next character resulting from a previous call has been stored (no
<pre>
- bytes from the input have been consumed by this call).</pre>
+ bytes from the input have been consumed by this call).
+</pre>
(size_t)(-2) if the next n bytes contribute to an incomplete (but potentially valid)
<pre>
multibyte character, and all n bytes have been processed (no value is
- stored).<sup><a href="#note311"><b>311)</b></a></sup></pre>
+ stored).<sup><a href="#note311"><b>311)</b></a></sup>
+</pre>
(size_t)(-1) if an encoding error occurs, in which case the next n or fewer bytes
<pre>
do not contribute to a complete and valid multibyte character (no
value is stored); the value of the macro EILSEQ is stored in errno,
- and the conversion state is unspecified.</pre>
+ and the conversion state is unspecified.
+</pre>
<h6>footnotes</h6>
<p><small><a name="note311" href="#note311">311)</a> When n has at least the value of the MB_CUR_MAX macro, this case can only occur if s points at a
sequence of redundant shift sequences (for implementations with state-dependent encodings).
</small>
-<a name="7.27.1.2" href="#7.27.1.2"><h5>7.27.1.2 The c16rtomb function</h5></a>
+<h5><a name="7.27.1.2" href="#7.27.1.2">7.27.1.2 The c16rtomb function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.27"><uchar.h></a>
size_t c16rtomb(char * restrict s, char16_t c16,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If s is a null pointer, the c16rtomb function is equivalent to the call
<pre>
- c16rtomb(buf, L'\0', ps)</pre>
+ c16rtomb(buf, L'\0', ps)
+</pre>
where buf is an internal buffer.
<p><!--para 3 -->
If s is not a null pointer, the c16rtomb function determines the number of bytes needed
the function stores the value of the macro EILSEQ in errno and returns
(size_t)(-1); the conversion state is unspecified.
-<a name="7.27.1.3" href="#7.27.1.3"><h5>7.27.1.3 The mbrtoc32 function</h5></a>
+<h5><a name="7.27.1.3" href="#7.27.1.3">7.27.1.3 The mbrtoc32 function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.27"><uchar.h></a>
size_t mbrtoc32(char32_t * restrict pc32,
const char * restrict s, size_t n,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If s is a null pointer, the mbrtoc32 function is equivalent to the call:
<pre>
- mbrtoc32(NULL, "", 1, ps)</pre>
+ mbrtoc32(NULL, "", 1, ps)
+</pre>
In this case, the values of the parameters pc32 and n are ignored.
<p><!--para 3 -->
If s is not a null pointer, the mbrtoc32 function inspects at most n bytes beginning with
conversion state):
0 if the next n or fewer bytes complete the multibyte character that
<pre>
- corresponds to the null wide character (which is the value stored).</pre>
+ corresponds to the null wide character (which is the value stored).
+</pre>
between 1 and n inclusive if the next n or fewer bytes complete a valid multibyte
<!--page 416 -->
<pre>
character (which is the value stored); the value returned is the number
- of bytes that complete the multibyte character.</pre>
+ of bytes that complete the multibyte character.
+</pre>
(size_t)(-3) if the next character resulting from a previous call has been stored (no
<pre>
- bytes from the input have been consumed by this call).</pre>
+ bytes from the input have been consumed by this call).
+</pre>
(size_t)(-2) if the next n bytes contribute to an incomplete (but potentially valid)
<pre>
multibyte character, and all n bytes have been processed (no value is
- stored).<sup><a href="#note312"><b>312)</b></a></sup></pre>
+ stored).<sup><a href="#note312"><b>312)</b></a></sup>
+</pre>
(size_t)(-1) if an encoding error occurs, in which case the next n or fewer bytes
<pre>
do not contribute to a complete and valid multibyte character (no
value is stored); the value of the macro EILSEQ is stored in errno,
- and the conversion state is unspecified.</pre>
+ and the conversion state is unspecified.
+</pre>
<h6>footnotes</h6>
<p><small><a name="note312" href="#note312">312)</a> When n has at least the value of the MB_CUR_MAX macro, this case can only occur if s points at a
sequence of redundant shift sequences (for implementations with state-dependent encodings).
</small>
-<a name="7.27.1.4" href="#7.27.1.4"><h5>7.27.1.4 The c32rtomb function</h5></a>
+<h5><a name="7.27.1.4" href="#7.27.1.4">7.27.1.4 The c32rtomb function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.27"><uchar.h></a>
size_t c32rtomb(char * restrict s, char32_t c32,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If s is a null pointer, the c32rtomb function is equivalent to the call
<pre>
- c32rtomb(buf, L'\0', ps)</pre>
+ c32rtomb(buf, L'\0', ps)
+</pre>
where buf is an internal buffer.
<p><!--para 3 -->
If s is not a null pointer, the c32rtomb function determines the number of bytes needed
<!--page 417 -->
-<a name="7.28" href="#7.28"><h3>7.28 Extended multibyte and wide character utilities <wchar.h></h3></a>
+<h3><a name="7.28" href="#7.28">7.28 Extended multibyte and wide character utilities <wchar.h></a></h3>
-<a name="7.28.1" href="#7.28.1"><h4>7.28.1 Introduction</h4></a>
+<h4><a name="7.28.1" href="#7.28.1">7.28.1 Introduction</a></h4>
<p><!--para 1 -->
The header <a href="#7.28"><wchar.h></a> defines four macros, and declares four data types, one tag, and
many functions.<sup><a href="#note313"><b>313)</b></a></sup>
<p><!--para 2 -->
The types declared are wchar_t and size_t (both described in <a href="#7.19">7.19</a>);
<pre>
- mbstate_t</pre>
+ mbstate_t
+</pre>
which is a complete object type other than an array type that can hold the conversion state
information necessary to convert between sequences of multibyte characters and wide
characters;
<pre>
- wint_t</pre>
+ wint_t
+</pre>
which is an integer type unchanged by default argument promotions that can hold any
value corresponding to members of the extended character set, as well as at least one
value that does not correspond to any member of the extended character set (see WEOF
below);<sup><a href="#note314"><b>314)</b></a></sup> and
<pre>
- struct tm</pre>
+ struct tm
+</pre>
which is declared as an incomplete structure type (the contents are described in <a href="#7.26.1">7.26.1</a>).
<p><!--para 3 -->
The macros defined are NULL (described in <a href="#7.19">7.19</a>); WCHAR_MIN and WCHAR_MAX
(described in <a href="#7.20.3">7.20.3</a>); and
<pre>
- WEOF</pre>
+ WEOF
+</pre>
which expands to a constant expression of type wint_t whose value does not
correspond to any member of the extended character set.<sup><a href="#note315"><b>315)</b></a></sup> It is accepted (and returned)
by several functions in this subclause to indicate end-of-file, that is, no more input from a
<p><small><a name="note315" href="#note315">315)</a> The value of the macro WEOF may differ from that of EOF and need not be negative.
</small>
-<a name="7.28.2" href="#7.28.2"><h4>7.28.2 Formatted wide character input/output functions</h4></a>
+<h4><a name="7.28.2" href="#7.28.2">7.28.2 Formatted wide character input/output functions</a></h4>
<p><!--para 1 -->
The formatted wide character input/output functions shall behave as if there is a sequence
point after the actions associated with each specifier.<sup><a href="#note316"><b>316)</b></a></sup>
<p><small><a name="note316" href="#note316">316)</a> The fwprintf functions perform writes to memory for the %n specifier.
</small>
-<a name="7.28.2.1" href="#7.28.2.1"><h5>7.28.2.1 The fwprintf function</h5></a>
+<h5><a name="7.28.2.1" href="#7.28.2.1">7.28.2.1 The fwprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
int fwprintf(FILE * restrict stream,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fwprintf function writes output to the stream pointed to by stream, under
The flag wide characters and their meanings are:
- The result of the conversion is left-justified within the field. (It is right-justified if
<pre>
- this flag is not specified.)</pre>
+ this flag is not specified.)
+</pre>
+ The result of a signed conversion always begins with a plus or minus sign. (It
<pre>
begins with a sign only when a negative value is converted if this flag is not
- specified.)<sup><a href="#note318"><b>318)</b></a></sup></pre>
+ specified.)<sup><a href="#note318"><b>318)</b></a></sup>
+</pre>
space If the first wide character of a signed conversion is not a sign, or if a signed
<pre>
conversion results in no wide characters, a space is prefixed to the result. If the
- space and + flags both appear, the space flag is ignored.</pre>
+ space and + flags both appear, the space flag is ignored.
+</pre>
# The result is converted to an ''alternative form''. For o conversion, it increases
<pre>
the precision, if and only if necessary, to force the first digit of the result to be a
zero (if the value and precision are both 0, a single 0 is printed). For x (or X)
- conversion, a nonzero result has 0x (or 0X) prefixed to it. For a, A, e, E, f, F, g,</pre>
+ conversion, a nonzero result has 0x (or 0X) prefixed to it. For a, A, e, E, f, F, g,
+</pre>
<!--page 420 -->
contains a decimal-point wide character, even if no digits follow it. (Normally, a
decimal-point wide character appears in the result of these conversions only if a
digit follows it.) For g and G conversions, trailing zeros are not removed from the
- result. For other conversions, the behavior is undefined.</pre>
+ result. For other conversions, the behavior is undefined.
+</pre>
0 For d, i, o, u, x, X, a, A, e, E, f, F, g, and G conversions, leading zeros
-<p><!--para 7 -->
<pre>
(following any indication of sign or base) are used to pad to the field width rather
than performing space padding, except when converting an infinity or NaN. If the
0 and - flags both appear, the 0 flag is ignored. For d, i, o, u, x, and X
conversions, if a precision is specified, the 0 flag is ignored. For other
- conversions, the behavior is undefined.</pre>
+ conversions, the behavior is undefined.
+</pre>
+<p><!--para 7 -->
The length modifiers and their meanings are:
hh Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
been promoted according to the integer promotions, but its value shall be
converted to signed char or unsigned char before printing); or that
a following n conversion specifier applies to a pointer to a signed char
- argument.</pre>
+ argument.
+</pre>
h Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
short int or unsigned short int argument (the argument will
have been promoted according to the integer promotions, but its value shall
be converted to short int or unsigned short int before printing);
or that a following n conversion specifier applies to a pointer to a short
- int argument.</pre>
+ int argument.
+</pre>
l (ell) Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
long int or unsigned long int argument; that a following n
following c conversion specifier applies to a wint_t argument; that a
following s conversion specifier applies to a pointer to a wchar_t
argument; or has no effect on a following a, A, e, E, f, F, g, or G conversion
- specifier.</pre>
+ specifier.
+</pre>
ll (ell-ell) Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
long long int or unsigned long long int argument; or that a
following n conversion specifier applies to a pointer to a long long int
- argument.</pre>
+ argument.
+</pre>
j Specifies that a following d, i, o, u, x, or X conversion specifier applies to
<!--page 421 -->
<pre>
an intmax_t or uintmax_t argument; or that a following n conversion
- specifier applies to a pointer to an intmax_t argument.</pre>
+ specifier applies to a pointer to an intmax_t argument.
+</pre>
z Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
size_t or the corresponding signed integer type argument; or that a
following n conversion specifier applies to a pointer to a signed integer type
- corresponding to size_t argument.</pre>
+ corresponding to size_t argument.
+</pre>
t Specifies that a following d, i, o, u, x, or X conversion specifier applies to a
<pre>
ptrdiff_t or the corresponding unsigned integer type argument; or that a
following n conversion specifier applies to a pointer to a ptrdiff_t
- argument.</pre>
+ argument.
+</pre>
L Specifies that a following a, A, e, E, f, F, g, or G conversion specifier
<pre>
- applies to a long double argument.</pre>
+ applies to a long double argument.
+</pre>
If a length modifier appears with any conversion specifier other than as specified above,
the behavior is undefined.
<p><!--para 8 -->
precision specifies the minimum number of digits to appear; if the value
being converted can be represented in fewer digits, it is expanded with
leading zeros. The default precision is 1. The result of converting a zero
- value with a precision of zero is no wide characters.</pre>
+ value with a precision of zero is no wide characters.
+</pre>
o,u,x,X The unsigned int argument is converted to unsigned octal (o), unsigned
<pre>
decimal (u), or unsigned hexadecimal notation (x or X) in the style dddd; the
conversion. The precision specifies the minimum number of digits to appear;
if the value being converted can be represented in fewer digits, it is expanded
with leading zeros. The default precision is 1. The result of converting a
- zero value with a precision of zero is no wide characters.</pre>
+ zero value with a precision of zero is no wide characters.
+</pre>
f,F A double argument representing a floating-point number is converted to
<!--page 422 -->
<pre>
[-]nan or [-]nan(n-wchar-sequence) -- which style, and the meaning of
any n-wchar-sequence, is implementation-defined. The F conversion
specifier produces INF, INFINITY, or NAN instead of inf, infinity, or
- nan, respectively.<sup><a href="#note319"><b>319)</b></a></sup></pre>
+ nan, respectively.<sup><a href="#note319"><b>319)</b></a></sup>
+</pre>
e,E A double argument representing a floating-point number is converted in the
<pre>
style [-]d.ddd e(+-)dd, where there is one digit (which is nonzero if the
and only as many more digits as necessary to represent the exponent. If the
value is zero, the exponent is zero.
A double argument representing an infinity or NaN is converted in the style
- of an f or F conversion specifier.</pre>
+ of an f or F conversion specifier.
+</pre>
g,G A double argument representing a floating-point number is converted in
<pre>
style f or e (or in style F or E in the case of a G conversion specifier),
fractional portion of the result and the decimal-point wide character is
removed if there is no fractional portion remaining.
A double argument representing an infinity or NaN is converted in the style
- of an f or F conversion specifier.</pre>
+ of an f or F conversion specifier.
+</pre>
a,A A double argument representing a floating-point number is converted in the
<pre>
style [-]0xh.hhhh p(+-)d, where there is one hexadecimal digit (which is
nonzero if the argument is a normalized floating-point number and is
otherwise unspecified) before the decimal-point wide character<sup><a href="#note320"><b>320)</b></a></sup> and the
number of hexadecimal digits after it is equal to the precision; if the precision
- is missing and FLT_RADIX is a power of 2, then the precision is sufficient</pre>
+ is missing and FLT_RADIX is a power of 2, then the precision is sufficient
+</pre>
<!--page 423 -->
represent the decimal exponent of 2. If the value is zero, the exponent is
zero.
A double argument representing an infinity or NaN is converted in the style
- of an f or F conversion specifier.</pre>
+ of an f or F conversion specifier.
+</pre>
c If no l length modifier is present, the int argument is converted to a wide
<pre>
character as if by calling btowc and the resulting wide character is written.
If an l length modifier is present, the wint_t argument is converted to
- wchar_t and written.</pre>
+ wchar_t and written.
+</pre>
s If no l length modifier is present, the argument shall be a pointer to the initial
<pre>
element of a character array containing a multibyte character sequence
written up to (but not including) a terminating null wide character. If the
precision is specified, no more than that many wide characters are written. If
the precision is not specified or is greater than the size of the array, the array
- shall contain a null wide character.</pre>
+ shall contain a null wide character.
+</pre>
p The argument shall be a pointer to void. The value of the pointer is
<pre>
- converted to a sequence of printing wide characters, in an implementation-</pre>
+ converted to a sequence of printing wide characters, in an implementation-
+</pre>
<!--page 424 -->
<pre>
- defined manner.</pre>
+ defined manner.
+</pre>
n The argument shall be a pointer to signed integer into which is written the
<pre>
number of wide characters written to the output stream so far by this call to
fwprintf. No argument is converted, but one is consumed. If the
conversion specification includes any flags, a field width, or a precision, the
- behavior is undefined.</pre>
+ behavior is undefined.
+</pre>
% A % wide character is written. No argument is converted. The complete
-<p><!--para 9 -->
<pre>
- conversion specification shall be %%.</pre>
+ conversion specification shall be %%.
+</pre>
+<p><!--para 9 -->
If a conversion specification is invalid, the behavior is undefined.<sup><a href="#note322"><b>322)</b></a></sup> If any argument is
not the correct type for the corresponding conversion specification, the behavior is
undefined.
<p><!--para 11 -->
For a and A conversions, if FLT_RADIX is a power of 2, the value is correctly rounded
to a hexadecimal floating number with the given precision.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 12 -->
For a and A conversions, if FLT_RADIX is not a power of 2 and the result is not exactly
representable in the given precision, the result should be one of the two adjacent numbers
value if an output or encoding error occurred.
<!--page 425 -->
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 15 -->
The number of wide characters that can be produced by any single conversion shall be at
least 4095.
int day, hour, min;
fwprintf(stdout, L"%ls, %ls %d, %.2d:%.2d\n",
weekday, month, day, hour, min);
- fwprintf(stdout, L"pi = %.5f\n", 4 * atan(1.0));</pre>
+ fwprintf(stdout, L"pi = %.5f\n", 4 * atan(1.0));
+</pre>
<p><b> Forward references</b>: the btowc function (<a href="#7.28.6.1.1">7.28.6.1.1</a>), the mbrtowc function
(<a href="#7.28.6.3.2">7.28.6.3.2</a>).
the case of fixed-point conversion by the source value as well.
</small>
-<a name="7.28.2.2" href="#7.28.2.2"><h5>7.28.2.2 The fwscanf function</h5></a>
+<h5><a name="7.28.2.2" href="#7.28.2.2">7.28.2.2 The fwscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
int fwscanf(FILE * restrict stream,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fwscanf function reads input from the stream pointed to by stream, under
The length modifiers and their meanings are:
hh Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
- to an argument with type pointer to signed char or unsigned char.</pre>
+ to an argument with type pointer to signed char or unsigned char.
+</pre>
h Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to short int or unsigned short
- int.</pre>
+ int.
+</pre>
l (ell) Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to long int or unsigned long
int; that a following a, A, e, E, f, F, g, or G conversion specifier applies to
an argument with type pointer to double; or that a following c, s, or [
- conversion specifier applies to an argument with type pointer to wchar_t.</pre>
+ conversion specifier applies to an argument with type pointer to wchar_t.
+</pre>
ll (ell-ell) Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to long long int or unsigned
- long long int.</pre>
+ long long int.
+</pre>
j Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
- to an argument with type pointer to intmax_t or uintmax_t.</pre>
+ to an argument with type pointer to intmax_t or uintmax_t.
+</pre>
z Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to size_t or the corresponding signed
- integer type.</pre>
+ integer type.
+</pre>
t Specifies that a following d, i, o, u, x, X, or n conversion specifier applies
<pre>
to an argument with type pointer to ptrdiff_t or the corresponding
- unsigned integer type.</pre>
+ unsigned integer type.
+</pre>
L Specifies that a following a, A, e, E, f, F, g, or G conversion specifier
<pre>
- applies to an argument with type pointer to long double.</pre>
+ applies to an argument with type pointer to long double.
+</pre>
If a length modifier appears with any conversion specifier other than as specified above,
the behavior is undefined.
<p><!--para 12 -->
<pre>
expected for the subject sequence of the wcstol function with the value 10
for the base argument. The corresponding argument shall be a pointer to
- signed integer.</pre>
+ signed integer.
+</pre>
i Matches an optionally signed integer, whose format is the same as expected
<!--page 428 -->
<pre>
for the subject sequence of the wcstol function with the value 0 for the
base argument. The corresponding argument shall be a pointer to signed
- integer.</pre>
+ integer.
+</pre>
o Matches an optionally signed octal integer, whose format is the same as
<pre>
expected for the subject sequence of the wcstoul function with the value 8
for the base argument. The corresponding argument shall be a pointer to
- unsigned integer.</pre>
+ unsigned integer.
+</pre>
u Matches an optionally signed decimal integer, whose format is the same as
<pre>
expected for the subject sequence of the wcstoul function with the value 10
for the base argument. The corresponding argument shall be a pointer to
- unsigned integer.</pre>
+ unsigned integer.
+</pre>
x Matches an optionally signed hexadecimal integer, whose format is the same
<pre>
as expected for the subject sequence of the wcstoul function with the value
16 for the base argument. The corresponding argument shall be a pointer to
- unsigned integer.</pre>
+ unsigned integer.
+</pre>
a,e,f,g Matches an optionally signed floating-point number, infinity, or NaN, whose
<pre>
format is the same as expected for the subject sequence of the wcstod
- function. The corresponding argument shall be a pointer to floating.</pre>
+ function. The corresponding argument shall be a pointer to floating.
+</pre>
c Matches a sequence of wide characters of exactly the number specified by the
<pre>
field width (1 if no field width is present in the directive).
accept the sequence. No null character is added.
If an l length modifier is present, the corresponding argument shall be a
pointer to the initial element of an array of wchar_t large enough to accept
- the sequence. No null wide character is added.</pre>
+ the sequence. No null wide character is added.
+</pre>
s Matches a sequence of non-white-space wide characters.
<!--page 429 -->
<pre>
If an l length modifier is present, the corresponding argument shall be a
pointer to the initial element of an array of wchar_t large enough to accept
the sequence and the terminating null wide character, which will be added
- automatically.</pre>
+ automatically.
+</pre>
[ Matches a nonempty sequence of wide characters from a set of expected
<pre>
characters (the scanset).
the specification; otherwise the first following right bracket wide character is
the one that ends the specification. If a - wide character is in the scanlist and
is not the first, nor the second where the first wide character is a ^, nor the
- last character, the behavior is implementation-defined.</pre>
+ last character, the behavior is implementation-defined.
+</pre>
p Matches an implementation-defined set of sequences, which should be the
<pre>
same as the set of sequences that may be produced by the %p conversion of
pointer to void. The input item is converted to a pointer value in an
implementation-defined manner. If the input item is a value converted earlier
during the same program execution, the pointer that results shall compare
- equal to that value; otherwise the behavior of the %p conversion is undefined.</pre>
+ equal to that value; otherwise the behavior of the %p conversion is undefined.
+</pre>
n No input is consumed. The corresponding argument shall be a pointer to
<!--page 430 -->
<pre>
completion of execution of the fwscanf function. No argument is
converted, but one is consumed. If the conversion specification includes an
assignment-suppressing wide character or a field width, the behavior is
- undefined.</pre>
+ undefined.
+</pre>
% Matches a single % wide character; no conversion or assignment occurs. The
-<p><!--para 13 -->
<pre>
- complete conversion specification shall be %%.</pre>
+ complete conversion specification shall be %%.
+</pre>
+<p><!--para 13 -->
If a conversion specification is invalid, the behavior is undefined.<sup><a href="#note326"><b>326)</b></a></sup>
<p><!--para 14 -->
The conversion specifiers A, E, F, G, and X are also valid and behave the same as,
#include <a href="#7.28"><wchar.h></a>
/* ... */
int n, i; float x; wchar_t name[50];
- n = fwscanf(stdin, L"%d%f%ls", &i, &x, name);</pre>
+ n = fwscanf(stdin, L"%d%f%ls", &i, &x, name);
+</pre>
with the input line:
<pre>
- 25 54.32E-1 thompson</pre>
+ 25 54.32E-1 thompson
+</pre>
will assign to n the value 3, to i the value 25, to x the value 5.432, and to name the sequence
thompson\0.
#include <a href="#7.28"><wchar.h></a>
/* ... */
int i; float x; double y;
- fwscanf(stdin, L"%2d%f%*d %lf", &i, &x, &y);</pre>
+ fwscanf(stdin, L"%2d%f%*d %lf", &i, &x, &y);
+</pre>
with input:
<pre>
- 56789 0123 56a72</pre>
+ 56789 0123 56a72
+</pre>
will assign to i the value 56 and to x the value 789.0, will skip past 0123, and will assign to y the value
56.0. The next wide character read from the input stream will be a.
<p><small><a name="note326" href="#note326">326)</a> See ''future library directions'' (<a href="#7.30.12">7.30.12</a>).
</small>
-<a name="7.28.2.3" href="#7.28.2.3"><h5>7.28.2.3 The swprintf function</h5></a>
+<h5><a name="7.28.2.3" href="#7.28.2.3">7.28.2.3 The swprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int swprintf(wchar_t * restrict s,
size_t n,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The swprintf function is equivalent to fwprintf, except that the argument s
counting the terminating null wide character, or a negative value if an encoding error
occurred or if n or more wide characters were requested to be written.
-<a name="7.28.2.4" href="#7.28.2.4"><h5>7.28.2.4 The swscanf function</h5></a>
+<h5><a name="7.28.2.4" href="#7.28.2.4">7.28.2.4 The swscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int swscanf(const wchar_t * restrict s,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The swscanf function is equivalent to fwscanf, except that the argument s specifies a
zero, in the event of an early matching failure.
<!--page 432 -->
-<a name="7.28.2.5" href="#7.28.2.5"><h5>7.28.2.5 The vfwprintf function</h5></a>
+<h5><a name="7.28.2.5" href="#7.28.2.5">7.28.2.5 The vfwprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int vfwprintf(FILE * restrict stream,
const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vfwprintf function is equivalent to fwprintf, with the variable argument list
// print out remainder of message
vfwprintf(stderr, format, args);
va_end(args);
- }</pre>
+ }
+</pre>
invoke the va_arg macro, the value of arg after the return is indeterminate.
</small>
-<a name="7.28.2.6" href="#7.28.2.6"><h5>7.28.2.6 The vfwscanf function</h5></a>
+<h5><a name="7.28.2.6" href="#7.28.2.6">7.28.2.6 The vfwscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int vfwscanf(FILE * restrict stream,
const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vfwscanf function is equivalent to fwscanf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vfwscanf function does not invoke the
- va_end macro.327)
+ va_end macro.<sup><a href="#note327"><b>327)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vfwscanf function returns the value of the macro EOF if an input failure occurs
returns the number of input items assigned, which can be fewer than provided for, or even
zero, in the event of an early matching failure.
-<a name="7.28.2.7" href="#7.28.2.7"><h5>7.28.2.7 The vswprintf function</h5></a>
+<h5><a name="7.28.2.7" href="#7.28.2.7">7.28.2.7 The vswprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
int vswprintf(wchar_t * restrict s,
size_t n,
const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vswprintf function is equivalent to swprintf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vswprintf function does not invoke the
- va_end macro.327)
+ va_end macro.<sup><a href="#note327"><b>327)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vswprintf function returns the number of wide characters written in the array, not
occurred or if n or more wide characters were requested to be generated.
<!--page 434 -->
-<a name="7.28.2.8" href="#7.28.2.8"><h5>7.28.2.8 The vswscanf function</h5></a>
+<h5><a name="7.28.2.8" href="#7.28.2.8">7.28.2.8 The vswscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int vswscanf(const wchar_t * restrict s,
const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vswscanf function is equivalent to swscanf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vswscanf function does not invoke the
- va_end macro.327)
+ va_end macro.<sup><a href="#note327"><b>327)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vswscanf function returns the value of the macro EOF if an input failure occurs
returns the number of input items assigned, which can be fewer than provided for, or even
zero, in the event of an early matching failure.
-<a name="7.28.2.9" href="#7.28.2.9"><h5>7.28.2.9 The vwprintf function</h5></a>
+<h5><a name="7.28.2.9" href="#7.28.2.9">7.28.2.9 The vwprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
#include <a href="#7.28"><wchar.h></a>
int vwprintf(const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vwprintf function is equivalent to wprintf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vwprintf function does not invoke the
- va_end macro.327)
+ va_end macro.<sup><a href="#note327"><b>327)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vwprintf function returns the number of wide characters transmitted, or a negative
value if an output or encoding error occurred.
<!--page 435 -->
-<a name="7.28.2.10" href="#7.28.2.10"><h5>7.28.2.10 The vwscanf function</h5></a>
+<h5><a name="7.28.2.10" href="#7.28.2.10">7.28.2.10 The vwscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
#include <a href="#7.28"><wchar.h></a>
int vwscanf(const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The vwscanf function is equivalent to wscanf, with the variable argument list
replaced by arg, which shall have been initialized by the va_start macro (and
possibly subsequent va_arg calls). The vwscanf function does not invoke the
- va_end macro.327)
+ va_end macro.<sup><a href="#note327"><b>327)</b></a></sup>
<h6>Returns</h6>
<p><!--para 3 -->
The vwscanf function returns the value of the macro EOF if an input failure occurs
returns the number of input items assigned, which can be fewer than provided for, or even
zero, in the event of an early matching failure.
-<a name="7.28.2.11" href="#7.28.2.11"><h5>7.28.2.11 The wprintf function</h5></a>
+<h5><a name="7.28.2.11" href="#7.28.2.11">7.28.2.11 The wprintf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- int wprintf(const wchar_t * restrict format, ...);</pre>
+ int wprintf(const wchar_t * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wprintf function is equivalent to fwprintf with the argument stdout
The wprintf function returns the number of wide characters transmitted, or a negative
value if an output or encoding error occurred.
-<a name="7.28.2.12" href="#7.28.2.12"><h5>7.28.2.12 The wscanf function</h5></a>
+<h5><a name="7.28.2.12" href="#7.28.2.12">7.28.2.12 The wscanf function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- int wscanf(const wchar_t * restrict format, ...);</pre>
+ int wscanf(const wchar_t * restrict format, ...);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wscanf function is equivalent to fwscanf with the argument stdin interposed
returns the number of input items assigned, which can be fewer than provided for, or even
zero, in the event of an early matching failure.
-<a name="7.28.3" href="#7.28.3"><h4>7.28.3 Wide character input/output functions</h4></a>
+<h4><a name="7.28.3" href="#7.28.3">7.28.3 Wide character input/output functions</a></h4>
-<a name="7.28.3.1" href="#7.28.3.1"><h5>7.28.3.1 The fgetwc function</h5></a>
+<h5><a name="7.28.3.1" href="#7.28.3.1">7.28.3.1 The fgetwc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
- wint_t fgetwc(FILE *stream);</pre>
+ wint_t fgetwc(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If the end-of-file indicator for the input stream pointed to by stream is not set and a
Also, errno will be set to EILSEQ by input/output functions only if an encoding error occurs.
</small>
-<a name="7.28.3.2" href="#7.28.3.2"><h5>7.28.3.2 The fgetws function</h5></a>
+<h5><a name="7.28.3.2" href="#7.28.3.2">7.28.3.2 The fgetws function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
wchar_t *fgetws(wchar_t * restrict s,
- int n, FILE * restrict stream);</pre>
+ int n, FILE * restrict stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fgetws function reads at most one less than the number of wide characters
null pointer is returned. If a read or encoding error occurs during the operation, the array
contents are indeterminate and a null pointer is returned.
-<a name="7.28.3.3" href="#7.28.3.3"><h5>7.28.3.3 The fputwc function</h5></a>
+<h5><a name="7.28.3.3" href="#7.28.3.3">7.28.3.3 The fputwc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
- wint_t fputwc(wchar_t c, FILE *stream);</pre>
+ wint_t fputwc(wchar_t c, FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fputwc function writes the wide character specified by c to the output stream
error indicator for the stream is set and fputwc returns WEOF. If an encoding error
occurs, the value of the macro EILSEQ is stored in errno and fputwc returns WEOF.
-<a name="7.28.3.4" href="#7.28.3.4"><h5>7.28.3.4 The fputws function</h5></a>
+<h5><a name="7.28.3.4" href="#7.28.3.4">7.28.3.4 The fputws function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
int fputws(const wchar_t * restrict s,
- FILE * restrict stream);</pre>
+ FILE * restrict stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fputws function writes the wide string pointed to by s to the stream pointed to by
returns a nonnegative value.
<!--page 438 -->
-<a name="7.28.3.5" href="#7.28.3.5"><h5>7.28.3.5 The fwide function</h5></a>
+<h5><a name="7.28.3.5" href="#7.28.3.5">7.28.3.5 The fwide function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
- int fwide(FILE *stream, int mode);</pre>
+ int fwide(FILE *stream, int mode);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The fwide function determines the orientation of the stream pointed to by stream. If
<p><small><a name="note329" href="#note329">329)</a> If the orientation of the stream has already been determined, fwide does not change it.
</small>
-<a name="7.28.3.6" href="#7.28.3.6"><h5>7.28.3.6 The getwc function</h5></a>
+<h5><a name="7.28.3.6" href="#7.28.3.6">7.28.3.6 The getwc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
- wint_t getwc(FILE *stream);</pre>
+ wint_t getwc(FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The getwc function is equivalent to fgetwc, except that if it is implemented as a
The getwc function returns the next wide character from the input stream pointed to by
stream, or WEOF.
-<a name="7.28.3.7" href="#7.28.3.7"><h5>7.28.3.7 The getwchar function</h5></a>
+<h5><a name="7.28.3.7" href="#7.28.3.7">7.28.3.7 The getwchar function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- wint_t getwchar(void);</pre>
+ wint_t getwchar(void);
+</pre>
The getwchar function returns the next wide character from the input stream pointed to
by stdin, or WEOF.
-<a name="7.28.3.8" href="#7.28.3.8"><h5>7.28.3.8 The putwc function</h5></a>
+<h5><a name="7.28.3.8" href="#7.28.3.8">7.28.3.8 The putwc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
- wint_t putwc(wchar_t c, FILE *stream);</pre>
+ wint_t putwc(wchar_t c, FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The putwc function is equivalent to fputwc, except that if it is implemented as a
<p><!--para 3 -->
The putwc function returns the wide character written, or WEOF.
-<a name="7.28.3.9" href="#7.28.3.9"><h5>7.28.3.9 The putwchar function</h5></a>
+<h5><a name="7.28.3.9" href="#7.28.3.9">7.28.3.9 The putwchar function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- wint_t putwchar(wchar_t c);</pre>
+ wint_t putwchar(wchar_t c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The putwchar function is equivalent to putwc with the second argument stdout.
<p><!--para 3 -->
The putwchar function returns the character written, or WEOF.
-<a name="7.28.3.10" href="#7.28.3.10"><h5>7.28.3.10 The ungetwc function</h5></a>
+<h5><a name="7.28.3.10" href="#7.28.3.10">7.28.3.10 The ungetwc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
- wint_t ungetwc(wint_t c, FILE *stream);</pre>
+ wint_t ungetwc(wint_t c, FILE *stream);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The ungetwc function pushes the wide character specified by c back onto the input
The ungetwc function returns the wide character pushed back, or WEOF if the operation
fails.
-<a name="7.28.4" href="#7.28.4"><h4>7.28.4 General wide string utilities</h4></a>
+<h4><a name="7.28.4" href="#7.28.4">7.28.4 General wide string utilities</a></h4>
<p><!--para 1 -->
The header <a href="#7.28"><wchar.h></a> declares a number of functions useful for wide string
manipulation. Various methods are used for determining the lengths of the arrays, but in
zero wide characters.
<!--page 441 -->
-<a name="7.28.4.1" href="#7.28.4.1"><h5>7.28.4.1 Wide string numeric conversion functions</h5></a>
+<h5><a name="7.28.4.1" href="#7.28.4.1">7.28.4.1 Wide string numeric conversion functions</a></h5>
-<a name="7.28.4.1.1" href="#7.28.4.1.1"><h5>7.28.4.1.1 The wcstod, wcstof, and wcstold functions</h5></a>
+<h5><a name="7.28.4.1.1" href="#7.28.4.1.1">7.28.4.1.1 The wcstod, wcstof, and wcstold functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
float wcstof(const wchar_t * restrict nptr,
wchar_t ** restrict endptr);
long double wcstold(const wchar_t * restrict nptr,
- wchar_t ** restrict endptr);</pre>
+ wchar_t ** restrict endptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcstod, wcstof, and wcstold functions convert the initial portion of the wide
decimal-point wide character, then an optional binary exponent part as defined in
<a href="#6.4.4.2">6.4.4.2</a>;
<li> INF or INFINITY, or any other wide string equivalent except for case
-<li> NAN or NAN(n-wchar-sequenceopt), or any other wide string equivalent except for
+<li> NAN or NAN(n-wchar-sequence<sub>opt</sub>), or any other wide string equivalent except for
case in the NAN part, where:
<pre>
n-wchar-sequence:
digit
nondigit
n-wchar-sequence digit
- n-wchar-sequence nondigit</pre>
+ n-wchar-sequence nondigit
+</pre>
</ul>
The subject sequence is defined as the longest initial subsequence of the input wide
string, starting with the first non-white-space wide character, that is of the expected form.
sign, the sequence is interpreted as negated.<sup><a href="#note330"><b>330)</b></a></sup> A wide character sequence INF or
INFINITY is interpreted as an infinity, if representable in the return type, else like a
floating constant that is too large for the range of the return type. A wide character
- sequence NAN or NAN(n-wchar-sequenceopt) is interpreted as a quiet NaN, if supported
+ sequence NAN or NAN(n-wchar-sequence<sub>opt</sub>) is interpreted as a quiet NaN, if supported
in the return type, else like a subject sequence part that does not have the expected form;
the meaning of the n-wchar sequences is implementation-defined.<sup><a href="#note331"><b>331)</b></a></sup> A pointer to the
final wide string is stored in the object pointed to by endptr, provided that endptr is
If the subject sequence is empty or does not have the expected form, no conversion is
performed; the value of nptr is stored in the object pointed to by endptr, provided
that endptr is not a null pointer.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 8 -->
If the subject sequence has the hexadecimal form, FLT_RADIX is not a power of 2, and
the result is not exactly representable, the result should be one of the two numbers in the
to the same internal floating value, but if not will round to adjacent values.
</small>
-<a name="7.28.4.1.2" href="#7.28.4.1.2"><h5>7.28.4.1.2 The wcstol, wcstoll, wcstoul, and wcstoull functions</h5></a>
+<h5><a name="7.28.4.1.2" href="#7.28.4.1.2">7.28.4.1.2 The wcstol, wcstoll, wcstoul, and wcstoull functions</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
unsigned long long int wcstoull(
const wchar_t * restrict nptr,
wchar_t ** restrict endptr,
- int base);</pre>
+ int base);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcstol, wcstoll, wcstoul, and wcstoull functions convert the initial
LLONG_MAX, ULONG_MAX, or ULLONG_MAX is returned (according to the return type
sign of the value, if any), and the value of the macro ERANGE is stored in errno.
-<a name="7.28.4.2" href="#7.28.4.2"><h5>7.28.4.2 Wide string copying functions</h5></a>
+<h5><a name="7.28.4.2" href="#7.28.4.2">7.28.4.2 Wide string copying functions</a></h5>
-<a name="7.28.4.2.1" href="#7.28.4.2.1"><h5>7.28.4.2.1 The wcscpy function</h5></a>
+<h5><a name="7.28.4.2.1" href="#7.28.4.2.1">7.28.4.2.1 The wcscpy function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
wchar_t *wcscpy(wchar_t * restrict s1,
- const wchar_t * restrict s2);</pre>
+ const wchar_t * restrict s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcscpy function copies the wide string pointed to by s2 (including the terminating
The wcscpy function returns the value of s1.
<!--page 446 -->
-<a name="7.28.4.2.2" href="#7.28.4.2.2"><h5>7.28.4.2.2 The wcsncpy function</h5></a>
+<h5><a name="7.28.4.2.2" href="#7.28.4.2.2">7.28.4.2.2 The wcsncpy function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
wchar_t *wcsncpy(wchar_t * restrict s1,
const wchar_t * restrict s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsncpy function copies not more than n wide characters (those that follow a null
result will not be null-terminated.
</small>
-<a name="7.28.4.2.3" href="#7.28.4.2.3"><h5>7.28.4.2.3 The wmemcpy function</h5></a>
+<h5><a name="7.28.4.2.3" href="#7.28.4.2.3">7.28.4.2.3 The wmemcpy function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
wchar_t *wmemcpy(wchar_t * restrict s1,
const wchar_t * restrict s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wmemcpy function copies n wide characters from the object pointed to by s2 to the
<!--page 447 -->
-<a name="7.28.4.2.4" href="#7.28.4.2.4"><h5>7.28.4.2.4 The wmemmove function</h5></a>
+<h5><a name="7.28.4.2.4" href="#7.28.4.2.4">7.28.4.2.4 The wmemmove function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
wchar_t *wmemmove(wchar_t *s1, const wchar_t *s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wmemmove function copies n wide characters from the object pointed to by s2 to
<p><!--para 3 -->
The wmemmove function returns the value of s1.
-<a name="7.28.4.3" href="#7.28.4.3"><h5>7.28.4.3 Wide string concatenation functions</h5></a>
+<h5><a name="7.28.4.3" href="#7.28.4.3">7.28.4.3 Wide string concatenation functions</a></h5>
-<a name="7.28.4.3.1" href="#7.28.4.3.1"><h5>7.28.4.3.1 The wcscat function</h5></a>
+<h5><a name="7.28.4.3.1" href="#7.28.4.3.1">7.28.4.3.1 The wcscat function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
wchar_t *wcscat(wchar_t * restrict s1,
- const wchar_t * restrict s2);</pre>
+ const wchar_t * restrict s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcscat function appends a copy of the wide string pointed to by s2 (including the
<p><!--para 3 -->
The wcscat function returns the value of s1.
-<a name="7.28.4.3.2" href="#7.28.4.3.2"><h5>7.28.4.3.2 The wcsncat function</h5></a>
+<h5><a name="7.28.4.3.2" href="#7.28.4.3.2">7.28.4.3.2 The wcsncat function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
wchar_t *wcsncat(wchar_t * restrict s1,
const wchar_t * restrict s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsncat function appends not more than n wide characters (a null wide character
wcslen(s1)+n+1.
</small>
-<a name="7.28.4.4" href="#7.28.4.4"><h5>7.28.4.4 Wide string comparison functions</h5></a>
+<h5><a name="7.28.4.4" href="#7.28.4.4">7.28.4.4 Wide string comparison functions</a></h5>
<p><!--para 1 -->
Unless explicitly stated otherwise, the functions described in this subclause order two
wide characters the same way as two integers of the underlying integer type designated
by wchar_t.
-<a name="7.28.4.4.1" href="#7.28.4.4.1"><h5>7.28.4.4.1 The wcscmp function</h5></a>
+<h5><a name="7.28.4.4.1" href="#7.28.4.4.1">7.28.4.4.1 The wcscmp function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- int wcscmp(const wchar_t *s1, const wchar_t *s2);</pre>
+ int wcscmp(const wchar_t *s1, const wchar_t *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcscmp function compares the wide string pointed to by s1 to the wide string
accordingly as the wide string pointed to by s1 is greater than, equal to, or less than the
wide string pointed to by s2.
-<a name="7.28.4.4.2" href="#7.28.4.4.2"><h5>7.28.4.4.2 The wcscoll function</h5></a>
+<h5><a name="7.28.4.4.2" href="#7.28.4.4.2">7.28.4.4.2 The wcscoll function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- int wcscoll(const wchar_t *s1, const wchar_t *s2);</pre>
+ int wcscoll(const wchar_t *s1, const wchar_t *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcscoll function compares the wide string pointed to by s1 to the wide string
wide string pointed to by s2 when both are interpreted as appropriate to the current
locale.
-<a name="7.28.4.4.3" href="#7.28.4.4.3"><h5>7.28.4.4.3 The wcsncmp function</h5></a>
+<h5><a name="7.28.4.4.3" href="#7.28.4.4.3">7.28.4.4.3 The wcsncmp function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int wcsncmp(const wchar_t *s1, const wchar_t *s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsncmp function compares not more than n wide characters (those that follow a
accordingly as the possibly null-terminated array pointed to by s1 is greater than, equal
to, or less than the possibly null-terminated array pointed to by s2.
-<a name="7.28.4.4.4" href="#7.28.4.4.4"><h5>7.28.4.4.4 The wcsxfrm function</h5></a>
+<h5><a name="7.28.4.4.4" href="#7.28.4.4.4">7.28.4.4.4 The wcsxfrm function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
size_t wcsxfrm(wchar_t * restrict s1,
const wchar_t * restrict s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsxfrm function transforms the wide string pointed to by s2 and places the
transformation of the wide string pointed to by s:
<!--page 450 -->
<pre>
- 1 + wcsxfrm(NULL, s, 0)</pre>
+ 1 + wcsxfrm(NULL, s, 0)
+</pre>
-<a name="7.28.4.4.5" href="#7.28.4.4.5"><h5>7.28.4.4.5 The wmemcmp function</h5></a>
+<h5><a name="7.28.4.4.5" href="#7.28.4.4.5">7.28.4.4.5 The wmemcmp function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int wmemcmp(const wchar_t *s1, const wchar_t *s2,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wmemcmp function compares the first n wide characters of the object pointed to by
accordingly as the object pointed to by s1 is greater than, equal to, or less than the object
pointed to by s2.
-<a name="7.28.4.5" href="#7.28.4.5"><h5>7.28.4.5 Wide string search functions</h5></a>
+<h5><a name="7.28.4.5" href="#7.28.4.5">7.28.4.5 Wide string search functions</a></h5>
-<a name="7.28.4.5.1" href="#7.28.4.5.1"><h5>7.28.4.5.1 The wcschr function</h5></a>
+<h5><a name="7.28.4.5.1" href="#7.28.4.5.1">7.28.4.5.1 The wcschr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- wchar_t *wcschr(const wchar_t *s, wchar_t c);</pre>
+ wchar_t *wcschr(const wchar_t *s, wchar_t c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcschr function locates the first occurrence of c in the wide string pointed to by s.
The wcschr function returns a pointer to the located wide character, or a null pointer if
the wide character does not occur in the wide string.
-<a name="7.28.4.5.2" href="#7.28.4.5.2"><h5>7.28.4.5.2 The wcscspn function</h5></a>
+<h5><a name="7.28.4.5.2" href="#7.28.4.5.2">7.28.4.5.2 The wcscspn function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- size_t wcscspn(const wchar_t *s1, const wchar_t *s2);</pre>
+ size_t wcscspn(const wchar_t *s1, const wchar_t *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcscspn function computes the length of the maximum initial segment of the wide
<p><!--para 3 -->
The wcscspn function returns the length of the segment.
-<a name="7.28.4.5.3" href="#7.28.4.5.3"><h5>7.28.4.5.3 The wcspbrk function</h5></a>
+<h5><a name="7.28.4.5.3" href="#7.28.4.5.3">7.28.4.5.3 The wcspbrk function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- wchar_t *wcspbrk(const wchar_t *s1, const wchar_t *s2);</pre>
+ wchar_t *wcspbrk(const wchar_t *s1, const wchar_t *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcspbrk function locates the first occurrence in the wide string pointed to by s1 of
The wcspbrk function returns a pointer to the wide character in s1, or a null pointer if
no wide character from s2 occurs in s1.
-<a name="7.28.4.5.4" href="#7.28.4.5.4"><h5>7.28.4.5.4 The wcsrchr function</h5></a>
+<h5><a name="7.28.4.5.4" href="#7.28.4.5.4">7.28.4.5.4 The wcsrchr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- wchar_t *wcsrchr(const wchar_t *s, wchar_t c);</pre>
+ wchar_t *wcsrchr(const wchar_t *s, wchar_t c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsrchr function locates the last occurrence of c in the wide string pointed to by
The wcsrchr function returns a pointer to the wide character, or a null pointer if c does
not occur in the wide string.
-<a name="7.28.4.5.5" href="#7.28.4.5.5"><h5>7.28.4.5.5 The wcsspn function</h5></a>
+<h5><a name="7.28.4.5.5" href="#7.28.4.5.5">7.28.4.5.5 The wcsspn function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- size_t wcsspn(const wchar_t *s1, const wchar_t *s2);</pre>
+ size_t wcsspn(const wchar_t *s1, const wchar_t *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsspn function computes the length of the maximum initial segment of the wide
The wcsspn function returns the length of the segment.
<!--page 452 -->
-<a name="7.28.4.5.6" href="#7.28.4.5.6"><h5>7.28.4.5.6 The wcsstr function</h5></a>
+<h5><a name="7.28.4.5.6" href="#7.28.4.5.6">7.28.4.5.6 The wcsstr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- wchar_t *wcsstr(const wchar_t *s1, const wchar_t *s2);</pre>
+ wchar_t *wcsstr(const wchar_t *s1, const wchar_t *s2);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsstr function locates the first occurrence in the wide string pointed to by s1 of
wide string is not found. If s2 points to a wide string with zero length, the function
returns s1.
-<a name="7.28.4.5.7" href="#7.28.4.5.7"><h5>7.28.4.5.7 The wcstok function</h5></a>
+<h5><a name="7.28.4.5.7" href="#7.28.4.5.7">7.28.4.5.7 The wcstok function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
wchar_t *wcstok(wchar_t * restrict s1,
const wchar_t * restrict s2,
- wchar_t ** restrict ptr);</pre>
+ wchar_t ** restrict ptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A sequence of calls to the wcstok function breaks the wide string pointed to by s1 into
t = wcstok(NULL, L",", &ptr1); // t points to the token L"??b"
t = wcstok(str2, L" \t", &ptr2); // t is a null pointer
t = wcstok(NULL, L"#,", &ptr1); // t points to the token L"c"
- t = wcstok(NULL, L"?", &ptr1); // t is a null pointer</pre>
+ t = wcstok(NULL, L"?", &ptr1); // t is a null pointer
+</pre>
-<a name="7.28.4.5.8" href="#7.28.4.5.8"><h5>7.28.4.5.8 The wmemchr function</h5></a>
+<h5><a name="7.28.4.5.8" href="#7.28.4.5.8">7.28.4.5.8 The wmemchr function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
wchar_t *wmemchr(const wchar_t *s, wchar_t c,
- size_t n);</pre>
+ size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wmemchr function locates the first occurrence of c in the initial n wide characters of
the wide character does not occur in the object.
<!--page 454 -->
-<a name="7.28.4.6" href="#7.28.4.6"><h5>7.28.4.6 Miscellaneous functions</h5></a>
+<h5><a name="7.28.4.6" href="#7.28.4.6">7.28.4.6 Miscellaneous functions</a></h5>
-<a name="7.28.4.6.1" href="#7.28.4.6.1"><h5>7.28.4.6.1 The wcslen function</h5></a>
+<h5><a name="7.28.4.6.1" href="#7.28.4.6.1">7.28.4.6.1 The wcslen function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- size_t wcslen(const wchar_t *s);</pre>
+ size_t wcslen(const wchar_t *s);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcslen function computes the length of the wide string pointed to by s.
The wcslen function returns the number of wide characters that precede the terminating
null wide character.
-<a name="7.28.4.6.2" href="#7.28.4.6.2"><h5>7.28.4.6.2 The wmemset function</h5></a>
+<h5><a name="7.28.4.6.2" href="#7.28.4.6.2">7.28.4.6.2 The wmemset function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- wchar_t *wmemset(wchar_t *s, wchar_t c, size_t n);</pre>
+ wchar_t *wmemset(wchar_t *s, wchar_t c, size_t n);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wmemset function copies the value of c into each of the first n wide characters of
<p><!--para 3 -->
The wmemset function returns the value of s.
-<a name="7.28.5" href="#7.28.5"><h4>7.28.5 Wide character time conversion functions</h4></a>
+<h4><a name="7.28.5" href="#7.28.5">7.28.5 Wide character time conversion functions</a></h4>
-<a name="7.28.5.1" href="#7.28.5.1"><h5>7.28.5.1 The wcsftime function</h5></a>
+<h5><a name="7.28.5.1" href="#7.28.5.1">7.28.5.1 The wcsftime function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
size_t wcsftime(wchar_t * restrict s,
size_t maxsize,
const wchar_t * restrict format,
- const struct tm * restrict timeptr);</pre>
+ const struct tm * restrict timeptr);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsftime function is equivalent to the strftime function, except that:
wide character. Otherwise, zero is returned and the contents of the array are
indeterminate.
-<a name="7.28.6" href="#7.28.6"><h4>7.28.6 Extended multibyte/wide character conversion utilities</h4></a>
+<h4><a name="7.28.6" href="#7.28.6">7.28.6 Extended multibyte/wide character conversion utilities</a></h4>
<p><!--para 1 -->
The header <a href="#7.28"><wchar.h></a> declares an extended set of functions useful for conversion
between multibyte characters and wide characters.
character string.
</small>
-<a name="7.28.6.1" href="#7.28.6.1"><h5>7.28.6.1 Single-byte/wide character conversion functions</h5></a>
+<h5><a name="7.28.6.1" href="#7.28.6.1">7.28.6.1 Single-byte/wide character conversion functions</a></h5>
-<a name="7.28.6.1.1" href="#7.28.6.1.1"><h5>7.28.6.1.1 The btowc function</h5></a>
+<h5><a name="7.28.6.1.1" href="#7.28.6.1.1">7.28.6.1.1 The btowc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a> *
- wint_t btowc(int c);</pre>
+ wint_t btowc(int c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The btowc function determines whether c constitutes a valid single-byte character in the
does not constitute a valid single-byte character in the initial shift state. Otherwise, it
returns the wide character representation of that character.
-<a name="7.28.6.1.2" href="#7.28.6.1.2"><h5>7.28.6.1.2 The wctob function</h5></a>
+<h5><a name="7.28.6.1.2" href="#7.28.6.1.2">7.28.6.1.2 The wctob function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a> *
- int wctob(wint_t c);</pre>
+ int wctob(wint_t c);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wctob function determines whether c corresponds to a member of the extended
length one in the initial shift state. Otherwise, it returns the single-byte representation of
that character as an unsigned char converted to an int.
-<a name="7.28.6.2" href="#7.28.6.2"><h5>7.28.6.2 Conversion state functions</h5></a>
+<h5><a name="7.28.6.2" href="#7.28.6.2">7.28.6.2 Conversion state functions</a></h5>
-<a name="7.28.6.2.1" href="#7.28.6.2.1"><h5>7.28.6.2.1 The mbsinit function</h5></a>
+<h5><a name="7.28.6.2.1" href="#7.28.6.2.1">7.28.6.2.1 The mbsinit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
- int mbsinit(const mbstate_t *ps);</pre>
+ int mbsinit(const mbstate_t *ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If ps is not a null pointer, the mbsinit function determines whether the referenced
The mbsinit function returns nonzero if ps is a null pointer or if the referenced object
describes an initial conversion state; otherwise, it returns zero.
-<a name="7.28.6.3" href="#7.28.6.3"><h5>7.28.6.3 Restartable multibyte/wide character conversion functions</h5></a>
+<h5><a name="7.28.6.3" href="#7.28.6.3">7.28.6.3 Restartable multibyte/wide character conversion functions</a></h5>
<p><!--para 1 -->
These functions differ from the corresponding multibyte character functions of <a href="#7.22.7">7.22.7</a>
(mblen, mbtowc, and wctomb) in that they have an extra parameter, ps, of type
Also unlike their corresponding functions, the return value does not represent whether the
encoding is state-dependent.
-<a name="7.28.6.3.1" href="#7.28.6.3.1"><h5>7.28.6.3.1 The mbrlen function</h5></a>
+<h5><a name="7.28.6.3.1" href="#7.28.6.3.1">7.28.6.3.1 The mbrlen function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
size_t mbrlen(const char * restrict s,
size_t n,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mbrlen function is equivalent to the call:
<pre>
- mbrtowc(NULL, s, n, ps != NULL ? ps : &internal)</pre>
+ mbrtowc(NULL, s, n, ps != NULL ? ps : &internal)
+</pre>
where internal is the mbstate_t object for the mbrlen function, except that the
expression designated by ps is evaluated only once.
<h6>Returns</h6>
<p><b> Forward references</b>: the mbrtowc function (<a href="#7.28.6.3.2">7.28.6.3.2</a>).
<!--page 458 -->
-<a name="7.28.6.3.2" href="#7.28.6.3.2"><h5>7.28.6.3.2 The mbrtowc function</h5></a>
+<h5><a name="7.28.6.3.2" href="#7.28.6.3.2">7.28.6.3.2 The mbrtowc function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
size_t mbrtowc(wchar_t * restrict pwc,
const char * restrict s,
size_t n,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If s is a null pointer, the mbrtowc function is equivalent to the call:
<pre>
- mbrtowc(NULL, "", 1, ps)</pre>
+ mbrtowc(NULL, "", 1, ps)
+</pre>
In this case, the values of the parameters pwc and n are ignored.
<p><!--para 3 -->
If s is not a null pointer, the mbrtowc function inspects at most n bytes beginning with
conversion state):
0 if the next n or fewer bytes complete the multibyte character that
<pre>
- corresponds to the null wide character (which is the value stored).</pre>
+ corresponds to the null wide character (which is the value stored).
+</pre>
between 1 and n inclusive if the next n or fewer bytes complete a valid multibyte
<pre>
character (which is the value stored); the value returned is the number
- of bytes that complete the multibyte character.</pre>
+ of bytes that complete the multibyte character.
+</pre>
(size_t)(-2) if the next n bytes contribute to an incomplete (but potentially valid)
<pre>
multibyte character, and all n bytes have been processed (no value is
- stored).<sup><a href="#note336"><b>336)</b></a></sup></pre>
+ stored).<sup><a href="#note336"><b>336)</b></a></sup>
+</pre>
(size_t)(-1) if an encoding error occurs, in which case the next n or fewer bytes
<pre>
do not contribute to a complete and valid multibyte character (no
value is stored); the value of the macro EILSEQ is stored in errno,
- and the conversion state is unspecified.</pre>
+ and the conversion state is unspecified.
+</pre>
<!--page 459 -->
sequence of redundant shift sequences (for implementations with state-dependent encodings).
</small>
-<a name="7.28.6.3.3" href="#7.28.6.3.3"><h5>7.28.6.3.3 The wcrtomb function</h5></a>
+<h5><a name="7.28.6.3.3" href="#7.28.6.3.3">7.28.6.3.3 The wcrtomb function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
size_t wcrtomb(char * restrict s,
wchar_t wc,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
If s is a null pointer, the wcrtomb function is equivalent to the call
<pre>
- wcrtomb(buf, L'\0', ps)</pre>
+ wcrtomb(buf, L'\0', ps)
+</pre>
where buf is an internal buffer.
<p><!--para 3 -->
If s is not a null pointer, the wcrtomb function determines the number of bytes needed
the function stores the value of the macro EILSEQ in errno and returns
(size_t)(-1); the conversion state is unspecified.
-<a name="7.28.6.4" href="#7.28.6.4"><h5>7.28.6.4 Restartable multibyte/wide string conversion functions</h5></a>
+<h5><a name="7.28.6.4" href="#7.28.6.4">7.28.6.4 Restartable multibyte/wide string conversion functions</a></h5>
<p><!--para 1 -->
These functions differ from the corresponding multibyte string functions of <a href="#7.22.8">7.22.8</a>
(mbstowcs and wcstombs) in that they have an extra parameter, ps, of type pointer to
to reflect the amount of the source processed by that invocation.
<!--page 460 -->
-<a name="7.28.6.4.1" href="#7.28.6.4.1"><h5>7.28.6.4.1 The mbsrtowcs function</h5></a>
+<h5><a name="7.28.6.4.1" href="#7.28.6.4.1">7.28.6.4.1 The mbsrtowcs function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
size_t mbsrtowcs(wchar_t * restrict dst,
const char ** restrict src,
size_t len,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The mbsrtowcs function converts a sequence of multibyte characters that begins in the
<p><small><a name="note337" href="#note337">337)</a> Thus, the value of len is ignored if dst is a null pointer.
</small>
-<a name="7.28.6.4.2" href="#7.28.6.4.2"><h5>7.28.6.4.2 The wcsrtombs function</h5></a>
+<h5><a name="7.28.6.4.2" href="#7.28.6.4.2">7.28.6.4.2 The wcsrtombs function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
size_t wcsrtombs(char * restrict dst,
const wchar_t ** restrict src,
size_t len,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsrtombs function converts a sequence of wide characters from the array
include those necessary to reach the initial shift state immediately before the null byte.
</small>
-<a name="7.29" href="#7.29"><h3>7.29 Wide character classification and mapping utilities <wctype.h></h3></a>
+<h3><a name="7.29" href="#7.29">7.29 Wide character classification and mapping utilities <wctype.h></a></h3>
-<a name="7.29.1" href="#7.29.1"><h4>7.29.1 Introduction</h4></a>
+<h4><a name="7.29.1" href="#7.29.1">7.29.1 Introduction</a></h4>
<p><!--para 1 -->
The header <a href="#7.29"><wctype.h></a> defines one macro, and declares three data types and many
functions.<sup><a href="#note339"><b>339)</b></a></sup>
<p><!--para 2 -->
The types declared are
<pre>
- wint_t</pre>
+ wint_t
+</pre>
described in <a href="#7.28.1">7.28.1</a>;
<pre>
- wctrans_t</pre>
+ wctrans_t
+</pre>
which is a scalar type that can hold values which represent locale-specific character
mappings; and
<pre>
- wctype_t</pre>
+ wctype_t
+</pre>
which is a scalar type that can hold values which represent locale-specific character
classifications.
<p><!--para 3 -->
<p><small><a name="note339" href="#note339">339)</a> See ''future library directions'' (<a href="#7.30.13">7.30.13</a>).
</small>
-<a name="7.29.2" href="#7.29.2"><h4>7.29.2 Wide character classification utilities</h4></a>
+<h4><a name="7.29.2" href="#7.29.2">7.29.2 Wide character classification utilities</a></h4>
<p><!--para 1 -->
The header <a href="#7.29"><wctype.h></a> declares several functions useful for classifying wide
characters.
term control wide character refers to a member of a locale-specific set of wide characters
that are not printing wide characters.
-<a name="7.29.2.1" href="#7.29.2.1"><h5>7.29.2.1 Wide character classification functions</h5></a>
+<h5><a name="7.29.2.1" href="#7.29.2.1">7.29.2.1 Wide character classification functions</a></h5>
<p><!--para 1 -->
The functions in this subclause return nonzero (true) if and only if the value of the
argument wc conforms to that in the description of the function.
&& iswspace(wc) is true, but not both.
</small>
-<a name="7.29.2.1.1" href="#7.29.2.1.1"><h5>7.29.2.1.1 The iswalnum function</h5></a>
+<h5><a name="7.29.2.1.1" href="#7.29.2.1.1">7.29.2.1.1 The iswalnum function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswalnum(wint_t wc);</pre>
+ int iswalnum(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswalnum function tests for any wide character for which iswalpha or
iswdigit is true.
-<a name="7.29.2.1.2" href="#7.29.2.1.2"><h5>7.29.2.1.2 The iswalpha function</h5></a>
+<h5><a name="7.29.2.1.2" href="#7.29.2.1.2">7.29.2.1.2 The iswalpha function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswalpha(wint_t wc);</pre>
+ int iswalpha(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswalpha function tests for any wide character for which iswupper or
wide characters; all four combinations are possible.
</small>
-<a name="7.29.2.1.3" href="#7.29.2.1.3"><h5>7.29.2.1.3 The iswblank function</h5></a>
+<h5><a name="7.29.2.1.3" href="#7.29.2.1.3">7.29.2.1.3 The iswblank function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswblank(wint_t wc);</pre>
+ int iswblank(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswblank function tests for any wide character that is a standard blank wide
characters are the following: space (L' '), and horizontal tab (L'\t'). In the "C"
locale, iswblank returns true only for the standard blank characters.
-<a name="7.29.2.1.4" href="#7.29.2.1.4"><h5>7.29.2.1.4 The iswcntrl function</h5></a>
+<h5><a name="7.29.2.1.4" href="#7.29.2.1.4">7.29.2.1.4 The iswcntrl function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswcntrl(wint_t wc);</pre>
+ int iswcntrl(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswcntrl function tests for any control wide character.
-<a name="7.29.2.1.5" href="#7.29.2.1.5"><h5>7.29.2.1.5 The iswdigit function</h5></a>
+<h5><a name="7.29.2.1.5" href="#7.29.2.1.5">7.29.2.1.5 The iswdigit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswdigit(wint_t wc);</pre>
+ int iswdigit(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswdigit function tests for any wide character that corresponds to a decimal-digit
character (as defined in <a href="#5.2.1">5.2.1</a>).
-<a name="7.29.2.1.6" href="#7.29.2.1.6"><h5>7.29.2.1.6 The iswgraph function</h5></a>
+<h5><a name="7.29.2.1.6" href="#7.29.2.1.6">7.29.2.1.6 The iswgraph function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswgraph(wint_t wc);</pre>
+ int iswgraph(wint_t wc);
+</pre>
characters other than ' '.
</small>
-<a name="7.29.2.1.7" href="#7.29.2.1.7"><h5>7.29.2.1.7 The iswlower function</h5></a>
+<h5><a name="7.29.2.1.7" href="#7.29.2.1.7">7.29.2.1.7 The iswlower function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswlower(wint_t wc);</pre>
+ int iswlower(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswlower function tests for any wide character that corresponds to a lowercase
letter or is one of a locale-specific set of wide characters for which none of iswcntrl,
iswdigit, iswpunct, or iswspace is true.
-<a name="7.29.2.1.8" href="#7.29.2.1.8"><h5>7.29.2.1.8 The iswprint function</h5></a>
+<h5><a name="7.29.2.1.8" href="#7.29.2.1.8">7.29.2.1.8 The iswprint function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswprint(wint_t wc);</pre>
+ int iswprint(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswprint function tests for any printing wide character.
-<a name="7.29.2.1.9" href="#7.29.2.1.9"><h5>7.29.2.1.9 The iswpunct function</h5></a>
+<h5><a name="7.29.2.1.9" href="#7.29.2.1.9">7.29.2.1.9 The iswpunct function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswpunct(wint_t wc);</pre>
+ int iswpunct(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswpunct function tests for any printing wide character that is one of a locale-
specific set of punctuation wide characters for which neither iswspace nor iswalnum
- is true.342)
+ is true.<sup><a href="#note342"><b>342)</b></a></sup>
-<a name="7.29.2.1.10" href="#7.29.2.1.10"><h5>7.29.2.1.10 The iswspace function</h5></a>
+<h5><a name="7.29.2.1.10" href="#7.29.2.1.10">7.29.2.1.10 The iswspace function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswspace(wint_t wc);</pre>
+ int iswspace(wint_t wc);
+</pre>
set of white-space wide characters for which none of iswalnum, iswgraph, or
iswpunct is true.
-<a name="7.29.2.1.11" href="#7.29.2.1.11"><h5>7.29.2.1.11 The iswupper function</h5></a>
+<h5><a name="7.29.2.1.11" href="#7.29.2.1.11">7.29.2.1.11 The iswupper function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswupper(wint_t wc);</pre>
+ int iswupper(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswupper function tests for any wide character that corresponds to an uppercase
letter or is one of a locale-specific set of wide characters for which none of iswcntrl,
iswdigit, iswpunct, or iswspace is true.
-<a name="7.29.2.1.12" href="#7.29.2.1.12"><h5>7.29.2.1.12 The iswxdigit function</h5></a>
+<h5><a name="7.29.2.1.12" href="#7.29.2.1.12">7.29.2.1.12 The iswxdigit function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswxdigit(wint_t wc);</pre>
+ int iswxdigit(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswxdigit function tests for any wide character that corresponds to a
hexadecimal-digit character (as defined in <a href="#6.4.4.1">6.4.4.1</a>).
-<a name="7.29.2.2" href="#7.29.2.2"><h5>7.29.2.2 Extensible wide character classification functions</h5></a>
+<h5><a name="7.29.2.2" href="#7.29.2.2">7.29.2.2 Extensible wide character classification functions</a></h5>
<p><!--para 1 -->
The functions wctype and iswctype provide extensible wide character classification
as well as testing equivalent to that performed by the functions described in the previous
subclause (<a href="#7.29.2.1">7.29.2.1</a>).
-<a name="7.29.2.2.1" href="#7.29.2.2.1"><h5>7.29.2.2.1 The iswctype function</h5></a>
+<h5><a name="7.29.2.2.1" href="#7.29.2.2.1">7.29.2.2.1 The iswctype function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- int iswctype(wint_t wc, wctype_t desc);</pre>
+ int iswctype(wint_t wc, wctype_t desc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The iswctype function determines whether the wide character wc has the property
iswctype(wc, wctype("punct")) // iswpunct(wc)
iswctype(wc, wctype("space")) // iswspace(wc)
iswctype(wc, wctype("upper")) // iswupper(wc)
- iswctype(wc, wctype("xdigit")) // iswxdigit(wc)</pre>
+ iswctype(wc, wctype("xdigit")) // iswxdigit(wc)
+</pre>
<h6>Returns</h6>
<p><!--para 4 -->
The iswctype function returns nonzero (true) if and only if the value of the wide
function returns zero (false).
<p><b> Forward references</b>: the wctype function (<a href="#7.29.2.2.2">7.29.2.2.2</a>).
-<a name="7.29.2.2.2" href="#7.29.2.2.2"><h5>7.29.2.2.2 The wctype function</h5></a>
+<h5><a name="7.29.2.2.2" href="#7.29.2.2.2">7.29.2.2.2 The wctype function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- wctype_t wctype(const char *property);</pre>
+ wctype_t wctype(const char *property);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wctype function constructs a value with type wctype_t that describes a class of
as the second argument to the iswctype function; otherwise, it returns zero.
<!--page 468 -->
-<a name="7.29.3" href="#7.29.3"><h4>7.29.3 Wide character case mapping utilities</h4></a>
+<h4><a name="7.29.3" href="#7.29.3">7.29.3 Wide character case mapping utilities</a></h4>
<p><!--para 1 -->
The header <a href="#7.29"><wctype.h></a> declares several functions useful for mapping wide characters.
-<a name="7.29.3.1" href="#7.29.3.1"><h5>7.29.3.1 Wide character case mapping functions</h5></a>
+<h5><a name="7.29.3.1" href="#7.29.3.1">7.29.3.1 Wide character case mapping functions</a></h5>
-<a name="7.29.3.1.1" href="#7.29.3.1.1"><h5>7.29.3.1.1 The towlower function</h5></a>
+<h5><a name="7.29.3.1.1" href="#7.29.3.1.1">7.29.3.1.1 The towlower function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- wint_t towlower(wint_t wc);</pre>
+ wint_t towlower(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The towlower function converts an uppercase letter to a corresponding lowercase letter.
characters (always the same one for any given locale); otherwise, the argument is
returned unchanged.
-<a name="7.29.3.1.2" href="#7.29.3.1.2"><h5>7.29.3.1.2 The towupper function</h5></a>
+<h5><a name="7.29.3.1.2" href="#7.29.3.1.2">7.29.3.1.2 The towupper function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- wint_t towupper(wint_t wc);</pre>
+ wint_t towupper(wint_t wc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The towupper function converts a lowercase letter to a corresponding uppercase letter.
characters (always the same one for any given locale); otherwise, the argument is
returned unchanged.
-<a name="7.29.3.2" href="#7.29.3.2"><h5>7.29.3.2 Extensible wide character case mapping functions</h5></a>
+<h5><a name="7.29.3.2" href="#7.29.3.2">7.29.3.2 Extensible wide character case mapping functions</a></h5>
<p><!--para 1 -->
The functions wctrans and towctrans provide extensible wide character mapping as
well as case mapping equivalent to that performed by the functions described in the
previous subclause (<a href="#7.29.3.1">7.29.3.1</a>).
<!--page 469 -->
-<a name="7.29.3.2.1" href="#7.29.3.2.1"><h5>7.29.3.2.1 The towctrans function</h5></a>
+<h5><a name="7.29.3.2.1" href="#7.29.3.2.1">7.29.3.2.1 The towctrans function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- wint_t towctrans(wint_t wc, wctrans_t desc);</pre>
+ wint_t towctrans(wint_t wc, wctrans_t desc);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The towctrans function maps the wide character wc using the mapping described by
mapping function (<a href="#7.29.3.1">7.29.3.1</a>) in the comment that follows the expression:
<pre>
towctrans(wc, wctrans("tolower")) // towlower(wc)
- towctrans(wc, wctrans("toupper")) // towupper(wc)</pre>
+ towctrans(wc, wctrans("toupper")) // towupper(wc)
+</pre>
<h6>Returns</h6>
<p><!--para 4 -->
The towctrans function returns the mapped value of wc using the mapping described
by desc. If desc is zero, the towctrans function returns the value of wc.
-<a name="7.29.3.2.2" href="#7.29.3.2.2"><h5>7.29.3.2.2 The wctrans function</h5></a>
+<h5><a name="7.29.3.2.2" href="#7.29.3.2.2">7.29.3.2.2 The wctrans function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.29"><wctype.h></a>
- wctrans_t wctrans(const char *property);</pre>
+ wctrans_t wctrans(const char *property);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wctrans function constructs a value with type wctrans_t that describes a
as the second argument to the towctrans function; otherwise, it returns zero.
<!--page 470 -->
-<a name="7.30" href="#7.30"><h3>7.30 Future library directions</h3></a>
+<h3><a name="7.30" href="#7.30">7.30 Future library directions</a></h3>
<p><!--para 1 -->
The following names are grouped under individual headers for convenience. All external
names described below are reserved no matter what headers are included by the program.
-<a name="7.30.1" href="#7.30.1"><h4>7.30.1 Complex arithmetic <complex.h></h4></a>
+<h4><a name="7.30.1" href="#7.30.1">7.30.1 Complex arithmetic <complex.h></a></h4>
<p><!--para 1 -->
The function names
<pre>
cerf cexpm1 clog2
cerfc clog10 clgamma
- cexp2 clog1p ctgamma</pre>
+ cexp2 clog1p ctgamma
+</pre>
and the same names suffixed with f or l may be added to the declarations in the
<a href="#7.3"><complex.h></a> header.
-<a name="7.30.2" href="#7.30.2"><h4>7.30.2 Character handling <ctype.h></h4></a>
+<h4><a name="7.30.2" href="#7.30.2">7.30.2 Character handling <ctype.h></a></h4>
<p><!--para 1 -->
Function names that begin with either is or to, and a lowercase letter may be added to
the declarations in the <a href="#7.4"><ctype.h></a> header.
-<a name="7.30.3" href="#7.30.3"><h4>7.30.3 Errors <errno.h></h4></a>
+<h4><a name="7.30.3" href="#7.30.3">7.30.3 Errors <errno.h></a></h4>
<p><!--para 1 -->
Macros that begin with E and a digit or E and an uppercase letter may be added to the
declarations in the <a href="#7.5"><errno.h></a> header.
-<a name="7.30.4" href="#7.30.4"><h4>7.30.4 Format conversion of integer types <inttypes.h></h4></a>
+<h4><a name="7.30.4" href="#7.30.4">7.30.4 Format conversion of integer types <inttypes.h></a></h4>
<p><!--para 1 -->
Macro names beginning with PRI or SCN followed by any lowercase letter or X may be
added to the macros defined in the <a href="#7.8"><inttypes.h></a> header.
-<a name="7.30.5" href="#7.30.5"><h4>7.30.5 Localization <locale.h></h4></a>
+<h4><a name="7.30.5" href="#7.30.5">7.30.5 Localization <locale.h></a></h4>
<p><!--para 1 -->
Macros that begin with LC_ and an uppercase letter may be added to the definitions in
the <a href="#7.11"><locale.h></a> header.
-<a name="7.30.6" href="#7.30.6"><h4>7.30.6 Signal handling <signal.h></h4></a>
+<h4><a name="7.30.6" href="#7.30.6">7.30.6 Signal handling <signal.h></a></h4>
<p><!--para 1 -->
Macros that begin with either SIG and an uppercase letter or SIG_ and an uppercase
letter may be added to the definitions in the <a href="#7.14"><signal.h></a> header.
-<a name="7.30.7" href="#7.30.7"><h4>7.30.7 Boolean type and values <stdbool.h></h4></a>
+<h4><a name="7.30.7" href="#7.30.7">7.30.7 Boolean type and values <stdbool.h></a></h4>
<p><!--para 1 -->
The ability to undefine and perhaps then redefine the macros bool, true, and false is
an obsolescent feature.
-<a name="7.30.8" href="#7.30.8"><h4>7.30.8 Integer types <stdint.h></h4></a>
+<h4><a name="7.30.8" href="#7.30.8">7.30.8 Integer types <stdint.h></a></h4>
<p><!--para 1 -->
Typedef names beginning with int or uint and ending with _t may be added to the
types defined in the <a href="#7.20"><stdint.h></a> header. Macro names beginning with INT or UINT
<a href="#7.20"><stdint.h></a> header.
<!--page 471 -->
-<a name="7.30.9" href="#7.30.9"><h4>7.30.9 Input/output <stdio.h></h4></a>
+<h4><a name="7.30.9" href="#7.30.9">7.30.9 Input/output <stdio.h></a></h4>
<p><!--para 1 -->
Lowercase letters may be added to the conversion specifiers and length modifiers in
fprintf and fscanf. Other characters may be used in extensions.
The use of ungetc on a binary stream where the file position indicator is zero prior to *
the call is an obsolescent feature.
-<a name="7.30.10" href="#7.30.10"><h4>7.30.10 General utilities <stdlib.h></h4></a>
+<h4><a name="7.30.10" href="#7.30.10">7.30.10 General utilities <stdlib.h></a></h4>
<p><!--para 1 -->
Function names that begin with str and a lowercase letter may be added to the
declarations in the <a href="#7.22"><stdlib.h></a> header.
-<a name="7.30.11" href="#7.30.11"><h4>7.30.11 String handling <string.h></h4></a>
+<h4><a name="7.30.11" href="#7.30.11">7.30.11 String handling <string.h></a></h4>
<p><!--para 1 -->
Function names that begin with str, mem, or wcs and a lowercase letter may be added
to the declarations in the <a href="#7.23"><string.h></a> header.
-<a name="7.30.12" href="#7.30.12"><h4>7.30.12 Extended multibyte and wide character utilities <wchar.h></h4></a>
+<h4><a name="7.30.12" href="#7.30.12">7.30.12 Extended multibyte and wide character utilities <wchar.h></a></h4>
<p><!--para 1 -->
Function names that begin with wcs and a lowercase letter may be added to the
declarations in the <a href="#7.28"><wchar.h></a> header.
Lowercase letters may be added to the conversion specifiers and length modifiers in
fwprintf and fwscanf. Other characters may be used in extensions.
-<a name="7.30.13" href="#7.30.13"><h4>7.30.13 Wide character classification and mapping utilities</h4></a>
+<h4><a name="7.30.13" href="#7.30.13">7.30.13 Wide character classification and mapping utilities</a></h4>
<a href="#7.29"><wctype.h></a>
<p><!--para 1 -->
Function names that begin with is or to and a lowercase letter may be added to the
declarations in the <a href="#7.29"><wctype.h></a> header.
<!--page 472 -->
-<a name="A" href="#A"><h2>Annex A</h2></a>
-<p><!--para 1 -->
+<h2><a name="A" href="#A">Annex A</a></h2>
<pre>
(informative)
- Language syntax summary</pre>
+ Language syntax summary
+</pre>
+<p><!--para 1 -->
NOTE The notation is described in <a href="#6.1">6.1</a>.
-<a name="A.1" href="#A.1"><h3>A.1 Lexical grammar</h3></a>
+<h3><a name="A.1" href="#A.1">A.1 Lexical grammar</a></h3>
-<a name="A.1.1" href="#A.1.1"><h4>A.1.1 Lexical elements</h4></a>
+<h4><a name="A.1.1" href="#A.1.1">A.1.1 Lexical elements</a></h4>
(<a href="#6.4">6.4</a>) token:
<pre>
keyword
identifier
constant
string-literal
- punctuator</pre>
+ punctuator
+</pre>
(<a href="#6.4">6.4</a>) preprocessing-token:
<!--page 473 -->
<pre>
character-constant
string-literal
punctuator
- each non-white-space character that cannot be one of the above</pre>
+ each non-white-space character that cannot be one of the above
+</pre>
-<a name="A.1.2" href="#A.1.2"><h4>A.1.2 Keywords</h4></a>
+<h4><a name="A.1.2" href="#A.1.2">A.1.2 Keywords</a></h4>
(<a href="#6.4.1">6.4.1</a>) keyword: one of
<pre>
alignof goto union
enum static _Noreturn
extern struct _Static_assert
float switch _Thread_local
- for typedef</pre>
+ for typedef
+</pre>
-<a name="A.1.3" href="#A.1.3"><h4>A.1.3 Identifiers</h4></a>
+<h4><a name="A.1.3" href="#A.1.3">A.1.3 Identifiers</a></h4>
(<a href="#6.4.2.1">6.4.2.1</a>) identifier:
<pre>
identifier-nondigit
identifier identifier-nondigit
- identifier digit</pre>
+ identifier digit
+</pre>
(<a href="#6.4.2.1">6.4.2.1</a>) identifier-nondigit:
<pre>
nondigit
universal-character-name
- other implementation-defined characters</pre>
+ other implementation-defined characters
+</pre>
(<a href="#6.4.2.1">6.4.2.1</a>) nondigit: one of
<pre>
_ a b c d e f g h i j k l m
n o p q r s t u v w x y z
A B C D E F G H I J K L M
- N O P Q R S T U V W X Y Z</pre>
+ N O P Q R S T U V W X Y Z
+</pre>
(<a href="#6.4.2.1">6.4.2.1</a>) digit: one of
<!--page 474 -->
<pre>
- 0 1 2 3 4 5 6 7 8 9</pre>
+ 0 1 2 3 4 5 6 7 8 9
+</pre>
-<a name="A.1.4" href="#A.1.4"><h4>A.1.4 Universal character names</h4></a>
+<h4><a name="A.1.4" href="#A.1.4">A.1.4 Universal character names</a></h4>
(<a href="#6.4.3">6.4.3</a>) universal-character-name:
<pre>
\u hex-quad
- \U hex-quad hex-quad</pre>
+ \U hex-quad hex-quad
+</pre>
(<a href="#6.4.3">6.4.3</a>) hex-quad:
<pre>
hexadecimal-digit hexadecimal-digit
- hexadecimal-digit hexadecimal-digit</pre>
+ hexadecimal-digit hexadecimal-digit
+</pre>
-<a name="A.1.5" href="#A.1.5"><h4>A.1.5 Constants</h4></a>
+<h4><a name="A.1.5" href="#A.1.5">A.1.5 Constants</a></h4>
(<a href="#6.4.4">6.4.4</a>) constant:
<pre>
integer-constant
floating-constant
enumeration-constant
- character-constant</pre>
+ character-constant
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) integer-constant:
<pre>
- decimal-constant integer-suffixopt
- octal-constant integer-suffixopt
- hexadecimal-constant integer-suffixopt</pre>
+ decimal-constant integer-suffix<sub>opt</sub>
+ octal-constant integer-suffix<sub>opt</sub>
+ hexadecimal-constant integer-suffix<sub>opt</sub>
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) decimal-constant:
<pre>
nonzero-digit
- decimal-constant digit</pre>
+ decimal-constant digit
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) octal-constant:
<pre>
0
- octal-constant octal-digit</pre>
+ octal-constant octal-digit
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) hexadecimal-constant:
<pre>
hexadecimal-prefix hexadecimal-digit
- hexadecimal-constant hexadecimal-digit</pre>
+ hexadecimal-constant hexadecimal-digit
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) hexadecimal-prefix: one of
<pre>
- 0x 0X</pre>
+ 0x 0X
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) nonzero-digit: one of
<pre>
- 1 2 3 4 5 6 7 8 9</pre>
+ 1 2 3 4 5 6 7 8 9
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) octal-digit: one of
<!--page 475 -->
<pre>
- 0 1 2 3 4 5 6 7</pre>
+ 0 1 2 3 4 5 6 7
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) hexadecimal-digit: one of
<pre>
0 1 2 3 4 5 6 7 8 9
a b c d e f
- A B C D E F</pre>
+ A B C D E F
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) integer-suffix:
<pre>
- unsigned-suffix long-suffixopt
+ unsigned-suffix long-suffix<sub>opt</sub>
unsigned-suffix long-long-suffix
- long-suffix unsigned-suffixopt
- long-long-suffix unsigned-suffixopt</pre>
+ long-suffix unsigned-suffix<sub>opt</sub>
+ long-long-suffix unsigned-suffix<sub>opt</sub>
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) unsigned-suffix: one of
<pre>
- u U</pre>
+ u U
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) long-suffix: one of
<pre>
- l L</pre>
+ l L
+</pre>
(<a href="#6.4.4.1">6.4.4.1</a>) long-long-suffix: one of
<pre>
- ll LL</pre>
+ ll LL
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) floating-constant:
<pre>
decimal-floating-constant
- hexadecimal-floating-constant</pre>
+ hexadecimal-floating-constant
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) decimal-floating-constant:
<pre>
- fractional-constant exponent-partopt floating-suffixopt
- digit-sequence exponent-part floating-suffixopt</pre>
+ fractional-constant exponent-part<sub>opt</sub> floating-suffix<sub>opt</sub>
+ digit-sequence exponent-part floating-suffix<sub>opt</sub>
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) hexadecimal-floating-constant:
<pre>
hexadecimal-prefix hexadecimal-fractional-constant
- binary-exponent-part floating-suffixopt
+ binary-exponent-part floating-suffix<sub>opt</sub>
hexadecimal-prefix hexadecimal-digit-sequence
- binary-exponent-part floating-suffixopt</pre>
+ binary-exponent-part floating-suffix<sub>opt</sub>
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) fractional-constant:
<pre>
- digit-sequenceopt . digit-sequence
- digit-sequence .</pre>
+ digit-sequence<sub>opt</sub> . digit-sequence
+ digit-sequence .
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) exponent-part:
<pre>
- e signopt digit-sequence
- E signopt digit-sequence</pre>
+ e sign<sub>opt</sub> digit-sequence
+ E sign<sub>opt</sub> digit-sequence
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) sign: one of
<!--page 476 -->
<pre>
- + -</pre>
+ + -
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) digit-sequence:
<pre>
digit
- digit-sequence digit</pre>
+ digit-sequence digit
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) hexadecimal-fractional-constant:
<pre>
- hexadecimal-digit-sequenceopt .
+ hexadecimal-digit-sequence<sub>opt</sub> .
hexadecimal-digit-sequence
- hexadecimal-digit-sequence .</pre>
+ hexadecimal-digit-sequence .
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) binary-exponent-part:
<pre>
- p signopt digit-sequence
- P signopt digit-sequence</pre>
+ p sign<sub>opt</sub> digit-sequence
+ P sign<sub>opt</sub> digit-sequence
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) hexadecimal-digit-sequence:
<pre>
hexadecimal-digit
- hexadecimal-digit-sequence hexadecimal-digit</pre>
+ hexadecimal-digit-sequence hexadecimal-digit
+</pre>
(<a href="#6.4.4.2">6.4.4.2</a>) floating-suffix: one of
<pre>
- f l F L</pre>
+ f l F L
+</pre>
(<a href="#6.4.4.3">6.4.4.3</a>) enumeration-constant:
<pre>
- identifier</pre>
+ identifier
+</pre>
(<a href="#6.4.4.4">6.4.4.4</a>) character-constant:
<pre>
' c-char-sequence '
L' c-char-sequence '
u' c-char-sequence '
- U' c-char-sequence '</pre>
+ U' c-char-sequence '
+</pre>
(<a href="#6.4.4.4">6.4.4.4</a>) c-char-sequence:
<pre>
c-char
- c-char-sequence c-char</pre>
+ c-char-sequence c-char
+</pre>
(<a href="#6.4.4.4">6.4.4.4</a>) c-char:
<pre>
any member of the source character set except
the single-quote ', backslash \, or new-line character
- escape-sequence</pre>
+ escape-sequence
+</pre>
(<a href="#6.4.4.4">6.4.4.4</a>) escape-sequence:
<!--page 477 -->
<pre>
simple-escape-sequence
octal-escape-sequence
hexadecimal-escape-sequence
- universal-character-name</pre>
+ universal-character-name
+</pre>
(<a href="#6.4.4.4">6.4.4.4</a>) simple-escape-sequence: one of
<pre>
\' \" \? \\
- \a \b \f \n \r \t \v</pre>
+ \a \b \f \n \r \t \v
+</pre>
(<a href="#6.4.4.4">6.4.4.4</a>) octal-escape-sequence:
<pre>
\ octal-digit
\ octal-digit octal-digit
- \ octal-digit octal-digit octal-digit</pre>
+ \ octal-digit octal-digit octal-digit
+</pre>
(<a href="#6.4.4.4">6.4.4.4</a>) hexadecimal-escape-sequence:
<pre>
\x hexadecimal-digit
- hexadecimal-escape-sequence hexadecimal-digit</pre>
+ hexadecimal-escape-sequence hexadecimal-digit
+</pre>
-<a name="A.1.6" href="#A.1.6"><h4>A.1.6 String literals</h4></a>
+<h4><a name="A.1.6" href="#A.1.6">A.1.6 String literals</a></h4>
(<a href="#6.4.5">6.4.5</a>) string-literal:
<pre>
- encoding-prefixopt " s-char-sequenceopt "</pre>
+ encoding-prefix<sub>opt</sub> " s-char-sequence<sub>opt</sub> "
+</pre>
(<a href="#6.4.5">6.4.5</a>) encoding-prefix:
<pre>
u8
u
U
- L</pre>
+ L
+</pre>
(<a href="#6.4.5">6.4.5</a>) s-char-sequence:
<pre>
s-char
- s-char-sequence s-char</pre>
+ s-char-sequence s-char
+</pre>
(<a href="#6.4.5">6.4.5</a>) s-char:
<pre>
any member of the source character set except
the double-quote ", backslash \, or new-line character
- escape-sequence</pre>
+ escape-sequence
+</pre>
-<a name="A.1.7" href="#A.1.7"><h4>A.1.7 Punctuators</h4></a>
+<h4><a name="A.1.7" href="#A.1.7">A.1.7 Punctuators</a></h4>
(<a href="#6.4.6">6.4.6</a>) punctuator: one of
<!--page 478 -->
<pre>
? : ; ...
= *= /= %= += -= <<= >>= &= ^= |=
, # ##
- <: :> <% %> %: %:%:</pre>
+ <: :> <% %> %: %:%:
+</pre>
-<a name="A.1.8" href="#A.1.8"><h4>A.1.8 Header names</h4></a>
+<h4><a name="A.1.8" href="#A.1.8">A.1.8 Header names</a></h4>
(<a href="#6.4.7">6.4.7</a>) header-name:
<pre>
< h-char-sequence >
- " q-char-sequence "</pre>
+ " q-char-sequence "
+</pre>
(<a href="#6.4.7">6.4.7</a>) h-char-sequence:
<pre>
h-char
- h-char-sequence h-char</pre>
+ h-char-sequence h-char
+</pre>
(<a href="#6.4.7">6.4.7</a>) h-char:
<pre>
any member of the source character set except
- the new-line character and ></pre>
+ the new-line character and >
+</pre>
(<a href="#6.4.7">6.4.7</a>) q-char-sequence:
<pre>
q-char
- q-char-sequence q-char</pre>
+ q-char-sequence q-char
+</pre>
(<a href="#6.4.7">6.4.7</a>) q-char:
<pre>
any member of the source character set except
- the new-line character and "</pre>
+ the new-line character and "
+</pre>
-<a name="A.1.9" href="#A.1.9"><h4>A.1.9 Preprocessing numbers</h4></a>
+<h4><a name="A.1.9" href="#A.1.9">A.1.9 Preprocessing numbers</a></h4>
(<a href="#6.4.8">6.4.8</a>) pp-number:
<!--page 479 -->
<pre>
pp-number E sign
pp-number p sign
pp-number P sign
- pp-number .</pre>
+ pp-number .
+</pre>
-<a name="A.2" href="#A.2"><h3>A.2 Phrase structure grammar</h3></a>
+<h3><a name="A.2" href="#A.2">A.2 Phrase structure grammar</a></h3>
-<a name="A.2.1" href="#A.2.1"><h4>A.2.1 Expressions</h4></a>
+<h4><a name="A.2.1" href="#A.2.1">A.2.1 Expressions</a></h4>
(<a href="#6.5.1">6.5.1</a>) primary-expression:
<pre>
identifier
constant
string-literal
( expression )
- generic-selection</pre>
+ generic-selection
+</pre>
(<a href="#6.5.1.1">6.5.1.1</a>) generic-selection:
<pre>
- _Generic ( assignment-expression , generic-assoc-list )</pre>
+ _Generic ( assignment-expression , generic-assoc-list )
+</pre>
(<a href="#6.5.1.1">6.5.1.1</a>) generic-assoc-list:
<pre>
generic-association
- generic-assoc-list , generic-association</pre>
+ generic-assoc-list , generic-association
+</pre>
(<a href="#6.5.1.1">6.5.1.1</a>) generic-association:
<pre>
type-name : assignment-expression
- default : assignment-expression</pre>
+ default : assignment-expression
+</pre>
(<a href="#6.5.2">6.5.2</a>) postfix-expression:
<pre>
primary-expression
postfix-expression [ expression ]
- postfix-expression ( argument-expression-listopt )
+ postfix-expression ( argument-expression-list<sub>opt</sub> )
postfix-expression . identifier
postfix-expression -> identifier
postfix-expression ++
postfix-expression --
( type-name ) { initializer-list }
- ( type-name ) { initializer-list , }</pre>
+ ( type-name ) { initializer-list , }
+</pre>
(<a href="#6.5.2">6.5.2</a>) argument-expression-list:
<pre>
assignment-expression
- argument-expression-list , assignment-expression</pre>
+ argument-expression-list , assignment-expression
+</pre>
(<a href="#6.5.3">6.5.3</a>) unary-expression:
<!--page 480 -->
<pre>
unary-operator cast-expression
sizeof unary-expression
sizeof ( type-name )
- alignof ( type-name )</pre>
+ alignof ( type-name )
+</pre>
(<a href="#6.5.3">6.5.3</a>) unary-operator: one of
<pre>
- & * + - ~ !</pre>
+ & * + - ~ !
+</pre>
(<a href="#6.5.4">6.5.4</a>) cast-expression:
<pre>
unary-expression
- ( type-name ) cast-expression</pre>
+ ( type-name ) cast-expression
+</pre>
(<a href="#6.5.5">6.5.5</a>) multiplicative-expression:
<pre>
cast-expression
multiplicative-expression * cast-expression
multiplicative-expression / cast-expression
- multiplicative-expression % cast-expression</pre>
+ multiplicative-expression % cast-expression
+</pre>
(<a href="#6.5.6">6.5.6</a>) additive-expression:
<pre>
multiplicative-expression
additive-expression + multiplicative-expression
- additive-expression - multiplicative-expression</pre>
+ additive-expression - multiplicative-expression
+</pre>
(<a href="#6.5.7">6.5.7</a>) shift-expression:
<pre>
additive-expression
shift-expression << additive-expression
- shift-expression >> additive-expression</pre>
+ shift-expression >> additive-expression
+</pre>
(<a href="#6.5.8">6.5.8</a>) relational-expression:
<pre>
shift-expression
relational-expression < shift-expression
relational-expression > shift-expression
relational-expression <= shift-expression
- relational-expression >= shift-expression</pre>
+ relational-expression >= shift-expression
+</pre>
(<a href="#6.5.9">6.5.9</a>) equality-expression:
<pre>
relational-expression
equality-expression == relational-expression
- equality-expression != relational-expression</pre>
+ equality-expression != relational-expression
+</pre>
(<a href="#6.5.10">6.5.10</a>) AND-expression:
<pre>
equality-expression
- AND-expression & equality-expression</pre>
+ AND-expression & equality-expression
+</pre>
(<a href="#6.5.11">6.5.11</a>) exclusive-OR-expression:
<!--page 481 -->
<pre>
AND-expression
- exclusive-OR-expression ^ AND-expression</pre>
+ exclusive-OR-expression ^ AND-expression
+</pre>
(<a href="#6.5.12">6.5.12</a>) inclusive-OR-expression:
<pre>
exclusive-OR-expression
- inclusive-OR-expression | exclusive-OR-expression</pre>
+ inclusive-OR-expression | exclusive-OR-expression
+</pre>
(<a href="#6.5.13">6.5.13</a>) logical-AND-expression:
<pre>
inclusive-OR-expression
- logical-AND-expression && inclusive-OR-expression</pre>
+ logical-AND-expression && inclusive-OR-expression
+</pre>
(<a href="#6.5.14">6.5.14</a>) logical-OR-expression:
<pre>
logical-AND-expression
- logical-OR-expression || logical-AND-expression</pre>
+ logical-OR-expression || logical-AND-expression
+</pre>
(<a href="#6.5.15">6.5.15</a>) conditional-expression:
<pre>
logical-OR-expression
- logical-OR-expression ? expression : conditional-expression</pre>
+ logical-OR-expression ? expression : conditional-expression
+</pre>
(<a href="#6.5.16">6.5.16</a>) assignment-expression:
<pre>
conditional-expression
- unary-expression assignment-operator assignment-expression</pre>
+ unary-expression assignment-operator assignment-expression
+</pre>
(<a href="#6.5.16">6.5.16</a>) assignment-operator: one of
<pre>
- = *= /= %= += -= <<= >>= &= ^= |=</pre>
+ = *= /= %= += -= <<= >>= &= ^= |=
+</pre>
(<a href="#6.5.17">6.5.17</a>) expression:
<pre>
assignment-expression
- expression , assignment-expression</pre>
+ expression , assignment-expression
+</pre>
(<a href="#6.6">6.6</a>) constant-expression:
<pre>
- conditional-expression</pre>
+ conditional-expression
+</pre>
-<a name="A.2.2" href="#A.2.2"><h4>A.2.2 Declarations</h4></a>
+<h4><a name="A.2.2" href="#A.2.2">A.2.2 Declarations</a></h4>
(<a href="#6.7">6.7</a>) declaration:
<pre>
- declaration-specifiers init-declarator-listopt ;
- static_assert-declaration</pre>
+ declaration-specifiers init-declarator-list<sub>opt</sub> ;
+ static_assert-declaration
+</pre>
(<a href="#6.7">6.7</a>) declaration-specifiers:
<pre>
- storage-class-specifier declaration-specifiersopt
- type-specifier declaration-specifiersopt
- type-qualifier declaration-specifiersopt
- function-specifier declaration-specifiersopt
- alignment-specifier declaration-specifiersopt</pre>
+ storage-class-specifier declaration-specifiers<sub>opt</sub>
+ type-specifier declaration-specifiers<sub>opt</sub>
+ type-qualifier declaration-specifiers<sub>opt</sub>
+ function-specifier declaration-specifiers<sub>opt</sub>
+ alignment-specifier declaration-specifiers<sub>opt</sub>
+</pre>
(<a href="#6.7">6.7</a>) init-declarator-list:
<!--page 482 -->
<pre>
init-declarator
- init-declarator-list , init-declarator</pre>
+ init-declarator-list , init-declarator
+</pre>
(<a href="#6.7">6.7</a>) init-declarator:
<pre>
declarator
- declarator = initializer</pre>
+ declarator = initializer
+</pre>
(<a href="#6.7.1">6.7.1</a>) storage-class-specifier:
<pre>
typedef
static
_Thread_local
auto
- register</pre>
+ register
+</pre>
(<a href="#6.7.2">6.7.2</a>) type-specifier:
<pre>
void
atomic-type-specifier
struct-or-union-specifier
enum-specifier
- typedef-name</pre>
+ typedef-name
+</pre>
(<a href="#6.7.2.1">6.7.2.1</a>) struct-or-union-specifier:
<pre>
- struct-or-union identifieropt { struct-declaration-list }
- struct-or-union identifier</pre>
+ struct-or-union identifier<sub>opt</sub> { struct-declaration-list }
+ struct-or-union identifier
+</pre>
(<a href="#6.7.2.1">6.7.2.1</a>) struct-or-union:
<pre>
struct
- union</pre>
+ union
+</pre>
(<a href="#6.7.2.1">6.7.2.1</a>) struct-declaration-list:
<pre>
struct-declaration
- struct-declaration-list struct-declaration</pre>
+ struct-declaration-list struct-declaration
+</pre>
(<a href="#6.7.2.1">6.7.2.1</a>) struct-declaration:
<!--page 483 -->
<pre>
- specifier-qualifier-list struct-declarator-listopt ;
- static_assert-declaration</pre>
+ specifier-qualifier-list struct-declarator-list<sub>opt</sub> ;
+ static_assert-declaration
+</pre>
(<a href="#6.7.2.1">6.7.2.1</a>) specifier-qualifier-list:
<pre>
- type-specifier specifier-qualifier-listopt
- type-qualifier specifier-qualifier-listopt</pre>
+ type-specifier specifier-qualifier-list<sub>opt</sub>
+ type-qualifier specifier-qualifier-list<sub>opt</sub>
+</pre>
(<a href="#6.7.2.1">6.7.2.1</a>) struct-declarator-list:
<pre>
struct-declarator
- struct-declarator-list , struct-declarator</pre>
+ struct-declarator-list , struct-declarator
+</pre>
(<a href="#6.7.2.1">6.7.2.1</a>) struct-declarator:
<pre>
declarator
- declaratoropt : constant-expression</pre>
+ declarator<sub>opt</sub> : constant-expression
+</pre>
(<a href="#6.7.2.2">6.7.2.2</a>) enum-specifier:
<pre>
- enum identifieropt { enumerator-list }
- enum identifieropt { enumerator-list , }
- enum identifier</pre>
+ enum identifier<sub>opt</sub> { enumerator-list }
+ enum identifier<sub>opt</sub> { enumerator-list , }
+ enum identifier
+</pre>
(<a href="#6.7.2.2">6.7.2.2</a>) enumerator-list:
<pre>
enumerator
- enumerator-list , enumerator</pre>
+ enumerator-list , enumerator
+</pre>
(<a href="#6.7.2.2">6.7.2.2</a>) enumerator:
<pre>
enumeration-constant
- enumeration-constant = constant-expression</pre>
+ enumeration-constant = constant-expression
+</pre>
(<a href="#6.7.2.4">6.7.2.4</a>) atomic-type-specifier:
<pre>
- _Atomic ( type-name )</pre>
+ _Atomic ( type-name )
+</pre>
(<a href="#6.7.3">6.7.3</a>) type-qualifier:
<pre>
const
restrict
volatile
- _Atomic</pre>
+ _Atomic
+</pre>
(<a href="#6.7.4">6.7.4</a>) function-specifier:
<pre>
inline
- _Noreturn</pre>
+ _Noreturn
+</pre>
(<a href="#6.7.5">6.7.5</a>) alignment-specifier:
<pre>
_Alignas ( type-name )
- _Alignas ( constant-expression )</pre>
+ _Alignas ( constant-expression )
+</pre>
(<a href="#6.7.6">6.7.6</a>) declarator:
<!--page 484 -->
<pre>
- pointeropt direct-declarator</pre>
+ pointer<sub>opt</sub> direct-declarator
+</pre>
(<a href="#6.7.6">6.7.6</a>) direct-declarator:
<pre>
identifier
( declarator )
- direct-declarator [ type-qualifier-listopt assignment-expressionopt ]
- direct-declarator [ static type-qualifier-listopt assignment-expression ]
+ direct-declarator [ type-qualifier-list<sub>opt</sub> assignment-expression<sub>opt</sub> ]
+ direct-declarator [ static type-qualifier-list<sub>opt</sub> assignment-expression ]
direct-declarator [ type-qualifier-list static assignment-expression ]
- direct-declarator [ type-qualifier-listopt * ]
+ direct-declarator [ type-qualifier-list<sub>opt</sub> * ]
direct-declarator ( parameter-type-list )
- direct-declarator ( identifier-listopt )</pre>
+ direct-declarator ( identifier-list<sub>opt</sub> )
+</pre>
(<a href="#6.7.6">6.7.6</a>) pointer:
<pre>
- * type-qualifier-listopt
- * type-qualifier-listopt pointer</pre>
+ * type-qualifier-list<sub>opt</sub>
+ * type-qualifier-list<sub>opt</sub> pointer
+</pre>
(<a href="#6.7.6">6.7.6</a>) type-qualifier-list:
<pre>
type-qualifier
- type-qualifier-list type-qualifier</pre>
+ type-qualifier-list type-qualifier
+</pre>
(<a href="#6.7.6">6.7.6</a>) parameter-type-list:
<pre>
parameter-list
- parameter-list , ...</pre>
+ parameter-list , ...
+</pre>
(<a href="#6.7.6">6.7.6</a>) parameter-list:
<pre>
parameter-declaration
- parameter-list , parameter-declaration</pre>
+ parameter-list , parameter-declaration
+</pre>
(<a href="#6.7.6">6.7.6</a>) parameter-declaration:
<pre>
declaration-specifiers declarator
- declaration-specifiers abstract-declaratoropt</pre>
+ declaration-specifiers abstract-declarator<sub>opt</sub>
+</pre>
(<a href="#6.7.6">6.7.6</a>) identifier-list:
<pre>
identifier
- identifier-list , identifier</pre>
+ identifier-list , identifier
+</pre>
(<a href="#6.7.7">6.7.7</a>) type-name:
<pre>
- specifier-qualifier-list abstract-declaratoropt</pre>
+ specifier-qualifier-list abstract-declarator<sub>opt</sub>
+</pre>
(<a href="#6.7.7">6.7.7</a>) abstract-declarator:
<!--page 485 -->
<pre>
pointer
- pointeropt direct-abstract-declarator</pre>
+ pointer<sub>opt</sub> direct-abstract-declarator
+</pre>
(<a href="#6.7.7">6.7.7</a>) direct-abstract-declarator:
<pre>
( abstract-declarator )
- direct-abstract-declaratoropt [ type-qualifier-listopt
- assignment-expressionopt ]
- direct-abstract-declaratoropt [ static type-qualifier-listopt
+ direct-abstract-declarator<sub>opt</sub> [ type-qualifier-list<sub>opt</sub>
+ assignment-expression<sub>opt</sub> ]
+ direct-abstract-declarator<sub>opt</sub> [ static type-qualifier-list<sub>opt</sub>
assignment-expression ]
- direct-abstract-declaratoropt [ type-qualifier-list static
+ direct-abstract-declarator<sub>opt</sub> [ type-qualifier-list static
assignment-expression ]
- direct-abstract-declaratoropt [ * ]
- direct-abstract-declaratoropt ( parameter-type-listopt )</pre>
+ direct-abstract-declarator<sub>opt</sub> [ * ]
+ direct-abstract-declarator<sub>opt</sub> ( parameter-type-list<sub>opt</sub> )
+</pre>
(<a href="#6.7.8">6.7.8</a>) typedef-name:
<pre>
- identifier</pre>
+ identifier
+</pre>
(<a href="#6.7.9">6.7.9</a>) initializer:
<pre>
assignment-expression
{ initializer-list }
- { initializer-list , }</pre>
+ { initializer-list , }
+</pre>
(<a href="#6.7.9">6.7.9</a>) initializer-list:
<pre>
- designationopt initializer
- initializer-list , designationopt initializer</pre>
+ designation<sub>opt</sub> initializer
+ initializer-list , designation<sub>opt</sub> initializer
+</pre>
(<a href="#6.7.9">6.7.9</a>) designation:
<pre>
- designator-list =</pre>
+ designator-list =
+</pre>
(<a href="#6.7.9">6.7.9</a>) designator-list:
<pre>
designator
- designator-list designator</pre>
+ designator-list designator
+</pre>
(<a href="#6.7.9">6.7.9</a>) designator:
<pre>
[ constant-expression ]
- . identifier</pre>
+ . identifier
+</pre>
(<a href="#6.7.10">6.7.10</a>) static_assert-declaration:
<!--page 486 -->
<pre>
- _Static_assert ( constant-expression , string-literal ) ;</pre>
+ _Static_assert ( constant-expression , string-literal ) ;
+</pre>
-<a name="A.2.3" href="#A.2.3"><h4>A.2.3 Statements</h4></a>
+<h4><a name="A.2.3" href="#A.2.3">A.2.3 Statements</a></h4>
(<a href="#6.8">6.8</a>) statement:
<pre>
labeled-statement
expression-statement
selection-statement
iteration-statement
- jump-statement</pre>
+ jump-statement
+</pre>
(<a href="#6.8.1">6.8.1</a>) labeled-statement:
<pre>
identifier : statement
case constant-expression : statement
- default : statement</pre>
+ default : statement
+</pre>
(<a href="#6.8.2">6.8.2</a>) compound-statement:
<pre>
- { block-item-listopt }</pre>
+ { block-item-list<sub>opt</sub> }
+</pre>
(<a href="#6.8.2">6.8.2</a>) block-item-list:
<pre>
block-item
- block-item-list block-item</pre>
+ block-item-list block-item
+</pre>
(<a href="#6.8.2">6.8.2</a>) block-item:
<pre>
declaration
- statement</pre>
+ statement
+</pre>
(<a href="#6.8.3">6.8.3</a>) expression-statement:
<pre>
- expressionopt ;</pre>
+ expression<sub>opt</sub> ;
+</pre>
(<a href="#6.8.4">6.8.4</a>) selection-statement:
<pre>
if ( expression ) statement
if ( expression ) statement else statement
- switch ( expression ) statement</pre>
+ switch ( expression ) statement
+</pre>
(<a href="#6.8.5">6.8.5</a>) iteration-statement:
<pre>
while ( expression ) statement
do statement while ( expression ) ;
- for ( expressionopt ; expressionopt ; expressionopt ) statement
- for ( declaration expressionopt ; expressionopt ) statement</pre>
+ for ( expression<sub>opt</sub> ; expression<sub>opt</sub> ; expression<sub>opt</sub> ) statement
+ for ( declaration expression<sub>opt</sub> ; expression<sub>opt</sub> ) statement
+</pre>
(<a href="#6.8.6">6.8.6</a>) jump-statement:
<!--page 487 -->
<pre>
goto identifier ;
continue ;
break ;
- return expressionopt ;</pre>
+ return expression<sub>opt</sub> ;
+</pre>
-<a name="A.2.4" href="#A.2.4"><h4>A.2.4 External definitions</h4></a>
+<h4><a name="A.2.4" href="#A.2.4">A.2.4 External definitions</a></h4>
(<a href="#6.9">6.9</a>) translation-unit:
<pre>
external-declaration
- translation-unit external-declaration</pre>
+ translation-unit external-declaration
+</pre>
(<a href="#6.9">6.9</a>) external-declaration:
<pre>
function-definition
- declaration</pre>
+ declaration
+</pre>
(<a href="#6.9.1">6.9.1</a>) function-definition:
<pre>
- declaration-specifiers declarator declaration-listopt compound-statement</pre>
+ declaration-specifiers declarator declaration-list<sub>opt</sub> compound-statement
+</pre>
(<a href="#6.9.1">6.9.1</a>) declaration-list:
<pre>
declaration
- declaration-list declaration</pre>
+ declaration-list declaration
+</pre>
-<a name="A.3" href="#A.3"><h3>A.3 Preprocessing directives</h3></a>
+<h3><a name="A.3" href="#A.3">A.3 Preprocessing directives</a></h3>
(<a href="#6.10">6.10</a>) preprocessing-file:
<pre>
- groupopt</pre>
+ group<sub>opt</sub>
+</pre>
(<a href="#6.10">6.10</a>) group:
<pre>
group-part
- group group-part</pre>
+ group group-part
+</pre>
(<a href="#6.10">6.10</a>) group-part:
<pre>
if-section
control-line
text-line
- # non-directive</pre>
+ # non-directive
+</pre>
(<a href="#6.10">6.10</a>) if-section:
<pre>
- if-group elif-groupsopt else-groupopt endif-line</pre>
+ if-group elif-groups<sub>opt</sub> else-group<sub>opt</sub> endif-line
+</pre>
(<a href="#6.10">6.10</a>) if-group:
<pre>
- # if constant-expression new-line groupopt
- # ifdef identifier new-line groupopt
- # ifndef identifier new-line groupopt</pre>
+ # if constant-expression new-line group<sub>opt</sub>
+ # ifdef identifier new-line group<sub>opt</sub>
+ # ifndef identifier new-line group<sub>opt</sub>
+</pre>
(<a href="#6.10">6.10</a>) elif-groups:
<pre>
elif-group
- elif-groups elif-group</pre>
+ elif-groups elif-group
+</pre>
(<a href="#6.10">6.10</a>) elif-group:
<!--page 488 -->
<pre>
- # elif constant-expression new-line groupopt</pre>
+ # elif constant-expression new-line group<sub>opt</sub>
+</pre>
(<a href="#6.10">6.10</a>) else-group:
<pre>
- # else new-line groupopt</pre>
+ # else new-line group<sub>opt</sub>
+</pre>
(<a href="#6.10">6.10</a>) endif-line:
<pre>
- # endif new-line</pre>
+ # endif new-line
+</pre>
(<a href="#6.10">6.10</a>) control-line:
<pre>
# include pp-tokens new-line
# define identifier replacement-list new-line
- # define identifier lparen identifier-listopt )
+ # define identifier lparen identifier-list<sub>opt</sub> )
replacement-list new-line
# define identifier lparen ... ) replacement-list new-line
# define identifier lparen identifier-list , ... )
replacement-list new-line
# undef identifier new-line
# line pp-tokens new-line
- # error pp-tokensopt new-line
- # pragma pp-tokensopt new-line
- # new-line</pre>
+ # error pp-tokens<sub>opt</sub> new-line
+ # pragma pp-tokens<sub>opt</sub> new-line
+ # new-line
+</pre>
(<a href="#6.10">6.10</a>) text-line:
<pre>
- pp-tokensopt new-line</pre>
+ pp-tokens<sub>opt</sub> new-line
+</pre>
(<a href="#6.10">6.10</a>) non-directive:
<pre>
- pp-tokens new-line</pre>
+ pp-tokens new-line
+</pre>
(<a href="#6.10">6.10</a>) lparen:
<pre>
- a ( character not immediately preceded by white-space</pre>
+ a ( character not immediately preceded by white-space
+</pre>
(<a href="#6.10">6.10</a>) replacement-list:
<pre>
- pp-tokensopt</pre>
+ pp-tokens<sub>opt</sub>
+</pre>
(<a href="#6.10">6.10</a>) pp-tokens:
<pre>
preprocessing-token
- pp-tokens preprocessing-token</pre>
+ pp-tokens preprocessing-token
+</pre>
(<a href="#6.10">6.10</a>) new-line:
<!--page 489 -->
<pre>
- the new-line character</pre>
+ the new-line character
+</pre>
-<a name="B" href="#B"><h2>Annex B</h2></a>
+<h2><a name="B" href="#B">Annex B</a></h2>
<pre>
(informative)
- Library summary</pre>
+ Library summary
+</pre>
-<a name="B.1" href="#B.1"><h3>B.1 Diagnostics <assert.h></h3></a>
+<h3><a name="B.1" href="#B.1">B.1 Diagnostics <assert.h></a></h3>
<pre>
NDEBUG
static_assert
- void assert(scalar expression);</pre>
+ void assert(scalar expression);
+</pre>
-<a name="B.2" href="#B.2"><h3>B.2 Complex <complex.h></h3></a>
+<h3><a name="B.2" href="#B.2">B.2 Complex <complex.h></a></h3>
<!--page 490 -->
<!--page 491 -->
<pre>
long double complex cprojl(long double complex z);
double creal(double complex z);
float crealf(float complex z);
- long double creall(long double complex z);</pre>
+ long double creall(long double complex z);
+</pre>
-<a name="B.3" href="#B.3"><h3>B.3 Character handling <ctype.h></h3></a>
+<h3><a name="B.3" href="#B.3">B.3 Character handling <ctype.h></a></h3>
<pre>
int isalnum(int c);
int isalpha(int c);
int isupper(int c);
int isxdigit(int c);
int tolower(int c);
- int toupper(int c);</pre>
+ int toupper(int c);
+</pre>
-<a name="B.4" href="#B.4"><h3>B.4 Errors <errno.h></h3></a>
+<h3><a name="B.4" href="#B.4">B.4 Errors <errno.h></a></h3>
<pre>
EDOM EILSEQ ERANGE errno
__STDC_WANT_LIB_EXT1__
- errno_t</pre>
+ errno_t
+</pre>
-<a name="B.5" href="#B.5"><h3>B.5 Floating-point environment <fenv.h></h3></a>
+<h3><a name="B.5" href="#B.5">B.5 Floating-point environment <fenv.h></a></h3>
<!--page 492 -->
<pre>
fenv_t FE_OVERFLOW FE_TOWARDZERO
int fegetenv(fenv_t *envp);
int feholdexcept(fenv_t *envp);
int fesetenv(const fenv_t *envp);
- int feupdateenv(const fenv_t *envp);</pre>
+ int feupdateenv(const fenv_t *envp);
+</pre>
-<a name="B.6" href="#B.6"><h3>B.6 Characteristics of floating types <float.h></h3></a>
+<h3><a name="B.6" href="#B.6">B.6 Characteristics of floating types <float.h></a></h3>
<pre>
FLT_ROUNDS DBL_DIG FLT_MAX
FLT_EVAL_METHOD LDBL_DIG DBL_MAX
DBL_DECIMAL_DIG LDBL_MAX_EXP DBL_TRUE_MIN
LDBL_DECIMAL_DIG FLT_MAX_10_EXP LDBL_TRUE_MIN
DECIMAL_DIG DBL_MAX_10_EXP
- FLT_DIG LDBL_MAX_10_EXP</pre>
+ FLT_DIG LDBL_MAX_10_EXP
+</pre>
-<a name="B.7" href="#B.7"><h3>B.7 Format conversion of integer types <inttypes.h></h3></a>
+<h3><a name="B.7" href="#B.7">B.7 Format conversion of integer types <inttypes.h></a></h3>
<!--page 493 -->
<pre>
imaxdiv_t
intmax_t wcstoimax(const wchar_t * restrict nptr,
wchar_t ** restrict endptr, int base);
uintmax_t wcstoumax(const wchar_t * restrict nptr,
- wchar_t ** restrict endptr, int base);</pre>
+ wchar_t ** restrict endptr, int base);
+</pre>
-<a name="B.8" href="#B.8"><h3>B.8 Alternative spellings <iso646.h></h3></a>
+<h3><a name="B.8" href="#B.8">B.8 Alternative spellings <iso646.h></a></h3>
<pre>
and bitor not_eq xor
and_eq compl or xor_eq
- bitand not or_eq</pre>
+ bitand not or_eq
+</pre>
-<a name="B.9" href="#B.9"><h3>B.9 Sizes of integer types <limits.h></h3></a>
+<h3><a name="B.9" href="#B.9">B.9 Sizes of integer types <limits.h></a></h3>
<pre>
CHAR_BIT CHAR_MAX INT_MIN ULONG_MAX
SCHAR_MIN MB_LEN_MAX INT_MAX LLONG_MIN
SCHAR_MAX SHRT_MIN UINT_MAX LLONG_MAX
UCHAR_MAX SHRT_MAX LONG_MIN ULLONG_MAX
- CHAR_MIN USHRT_MAX LONG_MAX</pre>
+ CHAR_MIN USHRT_MAX LONG_MAX
+</pre>
-<a name="B.10" href="#B.10"><h3>B.10 Localization <locale.h></h3></a>
+<h3><a name="B.10" href="#B.10">B.10 Localization <locale.h></a></h3>
<pre>
struct lconv LC_ALL LC_CTYPE LC_NUMERIC
NULL LC_COLLATE LC_MONETARY LC_TIME
char *setlocale(int category, const char *locale);
- struct lconv *localeconv(void);</pre>
+ struct lconv *localeconv(void);
+</pre>
-<a name="B.11" href="#B.11"><h3>B.11 Mathematics <math.h></h3></a>
+<h3><a name="B.11" href="#B.11">B.11 Mathematics <math.h></a></h3>
<!--page 494 -->
<!--page 495 -->
<!--page 496 -->
int isless(real-floating x, real-floating y);
int islessequal(real-floating x, real-floating y);
int islessgreater(real-floating x, real-floating y);
- int isunordered(real-floating x, real-floating y);</pre>
+ int isunordered(real-floating x, real-floating y);
+</pre>
-<a name="B.12" href="#B.12"><h3>B.12 Nonlocal jumps <setjmp.h></h3></a>
+<h3><a name="B.12" href="#B.12">B.12 Nonlocal jumps <setjmp.h></a></h3>
<pre>
jmp_buf
int setjmp(jmp_buf env);
- _Noreturn void longjmp(jmp_buf env, int val);</pre>
+ _Noreturn void longjmp(jmp_buf env, int val);
+</pre>
-<a name="B.13" href="#B.13"><h3>B.13 Signal handling <signal.h></h3></a>
+<h3><a name="B.13" href="#B.13">B.13 Signal handling <signal.h></a></h3>
<!--page 499 -->
<pre>
sig_atomic_t SIG_IGN SIGILL SIGTERM
SIG_DFL SIGABRT SIGINT
SIG_ERR SIGFPE SIGSEGV
void (*signal(int sig, void (*func)(int)))(int);
- int raise(int sig);</pre>
+ int raise(int sig);
+</pre>
-<a name="B.14" href="#B.14"><h3>B.14 Alignment <stdalign.h></h3></a>
+<h3><a name="B.14" href="#B.14">B.14 Alignment <stdalign.h></a></h3>
<pre>
alignas
- __alignas_is_defined</pre>
+ __alignas_is_defined
+</pre>
-<a name="B.15" href="#B.15"><h3>B.15 Variable arguments <stdarg.h></h3></a>
+<h3><a name="B.15" href="#B.15">B.15 Variable arguments <stdarg.h></a></h3>
<pre>
va_list
type va_arg(va_list ap, type);
void va_copy(va_list dest, va_list src);
void va_end(va_list ap);
- void va_start(va_list ap, parmN);</pre>
+ void va_start(va_list ap, parmN);
+</pre>
-<a name="B.16" href="#B.16"><h3>B.16 Atomics <stdatomic.h></h3></a>
+<h3><a name="B.16" href="#B.16">B.16 Atomics <stdatomic.h></a></h3>
<!--page 500 -->
<!--page 501 -->
<pre>
volatile atomic_flag *object, memory_order order);
void atomic_flag_clear(volatile atomic_flag *object);
void atomic_flag_clear_explicit(
- volatile atomic_flag *object, memory_order order);</pre>
+ volatile atomic_flag *object, memory_order order);
+</pre>
-<a name="B.17" href="#B.17"><h3>B.17 Boolean type and values <stdbool.h></h3></a>
+<h3><a name="B.17" href="#B.17">B.17 Boolean type and values <stdbool.h></a></h3>
<pre>
bool
true
false
- __bool_true_false_are_defined</pre>
+ __bool_true_false_are_defined
+</pre>
-<a name="B.18" href="#B.18"><h3>B.18 Common definitions <stddef.h></h3></a>
+<h3><a name="B.18" href="#B.18">B.18 Common definitions <stddef.h></a></h3>
<pre>
ptrdiff_t max_align_t NULL
size_t wchar_t
offsetof(type, member-designator)
__STDC_WANT_LIB_EXT1__
- rsize_t</pre>
+ rsize_t
+</pre>
-<a name="B.19" href="#B.19"><h3>B.19 Integer types <stdint.h></h3></a>
+<h3><a name="B.19" href="#B.19">B.19 Integer types <stdint.h></a></h3>
<!--page 502 -->
<pre>
intN_t INT_LEASTN_MIN PTRDIFF_MAX
INTN_MAX UINTMAX_MAX UINTMAX_C(value)
UINTN_MAX PTRDIFF_MIN
__STDC_WANT_LIB_EXT1__
- RSIZE_MAX</pre>
+ RSIZE_MAX
+</pre>
-<a name="B.20" href="#B.20"><h3>B.20 Input/output <stdio.h></h3></a>
+<h3><a name="B.20" href="#B.20">B.20 Input/output <stdio.h></a></h3>
<!--page 503 -->
<!--page 504 -->
<!--page 505 -->
int vsscanf_s(const char * restrict s,
const char * restrict format,
va_list arg);
- char *gets_s(char *s, rsize_t n);</pre>
+ char *gets_s(char *s, rsize_t n);
+</pre>
-<a name="B.21" href="#B.21"><h3>B.21 General utilities <stdlib.h></h3></a>
+<h3><a name="B.21" href="#B.21">B.21 General utilities <stdlib.h></a></h3>
<!--page 506 -->
<!--page 507 -->
<pre>
const char * restrict src, rsize_t len);
errno_t wcstombs_s(size_t * restrict retval,
char * restrict dst, rsize_t dstmax,
- const wchar_t * restrict src, rsize_t len);</pre>
+ const wchar_t * restrict src, rsize_t len);
+</pre>
-<a name="B.22" href="#B.22"><h3>B.22 String handling <string.h></h3></a>
+<h3><a name="B.22" href="#B.22">B.22 String handling <string.h></a></h3>
<!--page 508 -->
<!--page 509 -->
<pre>
errno_t strerror_s(char *s, rsize_t maxsize,
errno_t errnum);
size_t strerrorlen_s(errno_t errnum);
- size_t strnlen_s(const char *s, size_t maxsize);</pre>
+ size_t strnlen_s(const char *s, size_t maxsize);
+</pre>
-<a name="B.23" href="#B.23"><h3>B.23 Type-generic math <tgmath.h></h3></a>
+<h3><a name="B.23" href="#B.23">B.23 Type-generic math <tgmath.h></a></h3>
<pre>
acos sqrt fmod nextafter
asin fabs frexp nexttoward
tanh floor logb cimag
exp fma lrint conj
log fmax lround cproj
- pow fmin nearbyint creal</pre>
+ pow fmin nearbyint creal
+</pre>
-<a name="B.24" href="#B.24"><h3>B.24 Threads <threads.h></h3></a>
+<h3><a name="B.24" href="#B.24">B.24 Threads <threads.h></a></h3>
<!--page 510 -->
<pre>
ONCE_FLAG_INIT mtx_plain
void tss_delete(tss_t key);
void *tss_get(tss_t key);
int tss_set(tss_t key, void *val);
- int xtime_get(xtime *xt, int base);</pre>
+ int xtime_get(xtime *xt, int base);
+</pre>
-<a name="B.25" href="#B.25"><h3>B.25 Date and time <time.h></h3></a>
+<h3><a name="B.25" href="#B.25">B.25 Date and time <time.h></a></h3>
<!--page 511 -->
<pre>
NULL size_t time_t
struct tm *gmtime_s(const time_t * restrict timer,
struct tm * restrict result);
struct tm *localtime_s(const time_t * restrict timer,
- struct tm * restrict result);</pre>
+ struct tm * restrict result);
+</pre>
-<a name="B.26" href="#B.26"><h3>B.26 Unicode utilities <uchar.h></h3></a>
+<h3><a name="B.26" href="#B.26">B.26 Unicode utilities <uchar.h></a></h3>
<pre>
mbstate_t size_t char16_t char32_t
size_t mbrtoc16(char16_t * restrict pc16,
const char * restrict s, size_t n,
mbstate_t * restrict ps);
size_t c32rtomb(char * restrict s, char32_t c32,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
-<a name="B.27" href="#B.27"><h3>B.27 Extended multibyte/wide character utilities <wchar.h></h3></a>
+<h3><a name="B.27" href="#B.27">B.27 Extended multibyte/wide character utilities <wchar.h></a></h3>
<!--page 512 -->
<!--page 513 -->
<!--page 514 -->
errno_t wcsrtombs_s(size_t * restrict retval,
char * restrict dst, rsize_t dstmax,
const wchar_t ** restrict src, rsize_t len,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
-<a name="B.28" href="#B.28"><h3>B.28 Wide character classification and mapping utilities <wctype.h></h3></a>
+<h3><a name="B.28" href="#B.28">B.28 Wide character classification and mapping utilities <wctype.h></a></h3>
<!--page 517 -->
<pre>
wint_t wctrans_t wctype_t WEOF
wint_t towlower(wint_t wc);
wint_t towupper(wint_t wc);
wint_t towctrans(wint_t wc, wctrans_t desc);
- wctrans_t wctrans(const char *property);</pre>
+ wctrans_t wctrans(const char *property);
+</pre>
-<a name="C" href="#C"><h2>Annex C</h2></a>
-<p><!--para 1 -->
+<h2><a name="C" href="#C">Annex C</a></h2>
<pre>
(informative)
- Sequence points</pre>
+ Sequence points
+</pre>
+<p><!--para 1 -->
The following are the sequence points described in <a href="#5.1.2.3">5.1.2.3</a>:
<ul>
<li> Between the evaluations of the function designator and actual arguments in a function
<!--page 518 -->
</ul>
-<a name="D" href="#D"><h2>Annex D</h2></a>
-<p><!--para 1 -->
+<h2><a name="D" href="#D">Annex D</a></h2>
<pre>
(normative)
- Universal character names for identifiers</pre>
+ Universal character names for identifiers
+</pre>
+<p><!--para 1 -->
This clause lists the hexadecimal code values that are valid in universal character names
in identifiers.
-<a name="D.1" href="#D.1"><h3>D.1 Ranges of characters allowed</h3></a>
+<h3><a name="D.1" href="#D.1">D.1 Ranges of characters allowed</a></h3>
<p><!--para 1 -->
00A8, 00AA, 00AD, 00AF, 00B2-00B5, 00B7-00BA, 00BC-00BE, 00C0-00D6,
00D8-00F6, 00F8-00FF
60000-6FFFD, 70000-7FFFD, 80000-8FFFD, 90000-9FFFD, A0000-AFFFD,
B0000-BFFFD, C0000-CFFFD, D0000-DFFFD, E0000-EFFFD
-<a name="D.2" href="#D.2"><h3>D.2 Ranges of characters disallowed initially</h3></a>
+<h3><a name="D.2" href="#D.2">D.2 Ranges of characters disallowed initially</a></h3>
<p><!--para 1 -->
0300-036F, 1DC0-1DFF, 20D0-20FF, FE20-FE2F
<!--page 519 -->
-<a name="E" href="#E"><h2>Annex E</h2></a>
-<p><!--para 1 -->
+<h2><a name="E" href="#E">Annex E</a></h2>
<pre>
(informative)
- Implementation limits</pre>
+ Implementation limits
+</pre>
+<p><!--para 1 -->
The contents of the header <a href="#7.10"><limits.h></a> are given below, in alphabetical order. The
minimum magnitudes shown shall be replaced by implementation-defined magnitudes
with the same sign. The values shall all be constant expressions suitable for use in #if
preprocessing directives. The components are described further in <a href="#5.2.4.2.1">5.2.4.2.1</a>.
-<p><!--para 2 -->
<pre>
#define CHAR_BIT 8
#define CHAR_MAX UCHAR_MAX or SCHAR_MAX
#define USHRT_MAX 65535
#define UINT_MAX 65535
#define ULONG_MAX 4294967295
- #define ULLONG_MAX 18446744073709551615</pre>
+ #define ULLONG_MAX 18446744073709551615
+</pre>
+<p><!--para 2 -->
The contents of the header <a href="#7.7"><float.h></a> are given below. All integer values, except
FLT_ROUNDS, shall be constant expressions suitable for use in #if preprocessing
directives; all floating values shall be constant expressions. The components are
<p><!--para 3 -->
The values given in the following list shall be replaced by implementation-defined
expressions:
-<p><!--para 4 -->
<pre>
#define FLT_EVAL_METHOD
- #define FLT_ROUNDS</pre>
+ #define FLT_ROUNDS
+</pre>
+<p><!--para 4 -->
The values given in the following list shall be replaced by implementation-defined
constant expressions that are greater or equal in magnitude (absolute value) to those
shown, with the same sign:
<!--page 520 -->
-<p><!--para 5 -->
<pre>
#define DLB_DECIMAL_DIG 10
#define DBL_DIG 10
#define LDBL_MAX_10_EXP +37
#define LDBL_MAX_EXP
#define LDBL_MIN_10_EXP -37
- #define LDBL_MIN_EXP</pre>
+ #define LDBL_MIN_EXP
+</pre>
+<p><!--para 5 -->
The values given in the following list shall be replaced by implementation-defined
constant expressions with values that are greater than or equal to those shown:
-<p><!--para 6 -->
<pre>
#define DBL_MAX 1E+37
#define FLT_MAX 1E+37
- #define LDBL_MAX 1E+37</pre>
+ #define LDBL_MAX 1E+37
+</pre>
+<p><!--para 6 -->
The values given in the following list shall be replaced by implementation-defined
constant expressions with (positive) values that are less than or equal to those shown:
<!--page 521 -->
#define FLT_EPSILON 1E-5
#define FLT_MIN 1E-37
#define LDBL_EPSILON 1E-9
- #define LDBL_MIN 1E-37</pre>
+ #define LDBL_MIN 1E-37
+</pre>
-<a name="F" href="#F"><h2>Annex F</h2></a>
+<h2><a name="F" href="#F">Annex F</a></h2>
<pre>
(normative)
- IEC 60559 floating-point arithmetic</pre>
+ IEC 60559 floating-point arithmetic
+</pre>
-<a name="F.1" href="#F.1"><h3>F.1 Introduction</h3></a>
+<h3><a name="F.1" href="#F.1">F.1 Introduction</a></h3>
<p><!--para 1 -->
This annex specifies C language support for the IEC 60559 floating-point standard. The
IEC 60559 floating-point standard is specifically Binary floating-point arithmetic for
specifications.
</small>
-<a name="F.2" href="#F.2"><h3>F.2 Types</h3></a>
+<h3><a name="F.2" href="#F.2">F.2 Types</a></h3>
<p><!--para 1 -->
The C floating types match the IEC 60559 formats as follows:
<ul>
<!--page 522 -->
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 2 -->
The long double type should match an IEC 60559 extended format.
all double values.
</small>
-<a name="F.2.1" href="#F.2.1"><h4>F.2.1 Infinities, signed zeros, and NaNs</h4></a>
+<h4><a name="F.2.1" href="#F.2.1">F.2.1 Infinities, signed zeros, and NaNs</a></h4>
<p><!--para 1 -->
This specification does not define the behavior of signaling NaNs.<sup><a href="#note346"><b>346)</b></a></sup> It generally uses
the term NaN to denote quiet NaNs. The NAN and INFINITY macros and the nan
sufficient for closure of the arithmetic.
</small>
-<a name="F.3" href="#F.3"><h3>F.3 Operators and functions</h3></a>
+<h3><a name="F.3" href="#F.3">F.3 Operators and functions</a></h3>
<p><!--para 1 -->
C operators and functions provide IEC 60559 required and recommended facilities as
listed below.
macros defined in <a href="#7.12.3">7.12.3</a> do not distinguish signaling from quiet NaNs).
</ul>
-<a name="F.4" href="#F.4"><h3>F.4 Floating to integer conversion</h3></a>
+<h3><a name="F.4" href="#F.4">F.4 Floating to integer conversion</a></h3>
<p><!--para 1 -->
If the integer type is _Bool, <a href="#6.3.1.2">6.3.1.2</a> applies and no floating-point exceptions are raised
(even for NaN). Otherwise, if the floating value is infinite or NaN or if the integral part
<a href="#7.12"><math.h></a>.
</small>
-<a name="F.5" href="#F.5"><h3>F.5 Binary-decimal conversion</h3></a>
+<h3><a name="F.5" href="#F.5">F.5 Binary-decimal conversion</a></h3>
<p><!--para 1 -->
Conversion from the widest supported IEC 60559 format to decimal with
DECIMAL_DIG digits and back is the identity function.<sup><a href="#note348"><b>348)</b></a></sup>
DBL_DIG are 18 and 15, respectively, for these formats.)
</small>
-<a name="F.6" href="#F.6"><h3>F.6 The return statement</h3></a>
+<h3><a name="F.6" href="#F.6">F.6 The return statement</a></h3>
If the return expression is evaluated in a floating-point format different from the return
type, the expression is converted as if by assignment<sup><a href="#note349"><b>349)</b></a></sup> to the return type of the function
and the resulting value is returned to the caller.
<p><small><a name="note349" href="#note349">349)</a> Assignment removes any extra range and precision.
</small>
-<a name="F.7" href="#F.7"><h3>F.7 Contracted expressions</h3></a>
+<h3><a name="F.7" href="#F.7">F.7 Contracted expressions</a></h3>
<p><!--para 1 -->
A contracted expression is correctly rounded (once) and treats infinities, NaNs, signed
zeros, subnormals, and the rounding directions in a manner consistent with the basic
arithmetic operations covered by IEC 60559.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 2 -->
A contracted expression should raise floating-point exceptions in a manner generally
consistent with the basic arithmetic operations. *
-<a name="F.8" href="#F.8"><h3>F.8 Floating-point environment</h3></a>
+<h3><a name="F.8" href="#F.8">F.8 Floating-point environment</a></h3>
<p><!--para 1 -->
The floating-point environment defined in <a href="#7.6"><fenv.h></a> includes the IEC 60559 floating-
point exception status flags and directed-rounding control modes. It includes also
<p><small><a name="note350" href="#note350">350)</a> This specification does not require dynamic rounding precision nor trap enablement modes.
</small>
-<a name="F.8.1" href="#F.8.1"><h4>F.8.1 Environment management</h4></a>
+<h4><a name="F.8.1" href="#F.8.1">F.8.1 Environment management</a></h4>
<p><!--para 1 -->
IEC 60559 requires that floating-point operations implicitly raise floating-point exception
status flags, and that rounding control modes can be set explicitly to affect result values of
which allows certain optimizations (see <a href="#F.9">F.9</a>).
</small>
-<a name="F.8.2" href="#F.8.2"><h4>F.8.2 Translation</h4></a>
+<h4><a name="F.8.2" href="#F.8.2">F.8.2 Translation</a></h4>
<p><!--para 1 -->
During translation the IEC 60559 default modes are in effect:
<ul>
<li> The rounding precision mode (if supported) is set so that results are not shortened.
<li> Trapping or stopping (if supported) is disabled on all floating-point exceptions.
</ul>
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 2 -->
The implementation should produce a diagnostic message for each translation-time
floating-point exception, other than ''inexact'';<sup><a href="#note352"><b>352)</b></a></sup> the implementation should then
strtod, provide execution-time conversion of numeric strings.
</small>
-<a name="F.8.3" href="#F.8.3"><h4>F.8.3 Execution</h4></a>
+<h4><a name="F.8.3" href="#F.8.3">F.8.3 Execution</a></h4>
<p><!--para 1 -->
At program startup the floating-point environment is initialized as prescribed by
IEC 60559:
<li> Trapping or stopping (if supported) is disabled on all floating-point exceptions.
</ul>
-<a name="F.8.4" href="#F.8.4"><h4>F.8.4 Constant expressions</h4></a>
+<h4><a name="F.8.4" href="#F.8.4">F.8.4 Constant expressions</a></h4>
<p><!--para 1 -->
An arithmetic constant expression of floating type, other than one in an initializer for an
object that has static or thread storage duration, is evaluated (as if) during execution; thus,
<!--page 527 -->
-<p><!--para 3 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
#pragma STDC FENV_ACCESS ON
float y = 0.0/0.0; // raises an exception
double z = 0.0/0.0; // raises an exception
/* ... */
- }</pre>
+ }
+</pre>
+<p><!--para 3 -->
For the static initialization, the division is done at translation time, raising no (execution-time) floating-
point exceptions. On the other hand, for the three automatic initializations the invalid division occurs at
execution time.
efficiency of translation-time evaluation through static initialization, such as
<pre>
- const static double one_third = 1.0/3.0;</pre>
+ const static double one_third = 1.0/3.0;
+</pre>
</small>
-<a name="F.8.5" href="#F.8.5"><h4>F.8.5 Initialization</h4></a>
+<h4><a name="F.8.5" href="#F.8.5">F.8.5 Initialization</a></h4>
<p><!--para 1 -->
All computation for automatic initialization is done (as if) at execution time; thus, it is
affected by any operative modes and raises floating-point exceptions as required by
translation time.
<p><!--para 2 -->
EXAMPLE
-<p><!--para 3 -->
<pre>
#include <a href="#7.6"><fenv.h></a>
#pragma STDC FENV_ACCESS ON
float y = 1.1e75f; // may raise exceptions
long double z = 1.1e75; // does not raise exceptions
/* ... */
- }</pre>
+ }
+</pre>
+<p><!--para 3 -->
The static initialization of v raises no (execution-time) floating-point exceptions because its computation is
done at translation time. The automatic initialization of u and w require an execution-time conversion to
float of the wider value 1.1e75, which raises floating-point exceptions. The automatic initializations
For example, the automatic initialization
<pre>
- double_t x = 1.1e75;</pre>
+ double_t x = 1.1e75;
+</pre>
could be done at translation time, regardless of the expression evaluation method.
</small>
-<a name="F.8.6" href="#F.8.6"><h4>F.8.6 Changing the environment</h4></a>
+<h4><a name="F.8.6" href="#F.8.6">F.8.6 Changing the environment</a></h4>
<p><!--para 1 -->
Operations defined in <a href="#6.5">6.5</a> and functions and macros defined for the standard libraries
change floating-point status flags and control modes just as indicated by their
''inexact'', or ''underflow'' and ''inexact''), then ''overflow'' or ''underflow'' is raised
before ''inexact''.
-<a name="F.9" href="#F.9"><h3>F.9 Optimization</h3></a>
+<h3><a name="F.9" href="#F.9">F.9 Optimization</a></h3>
<p><!--para 1 -->
This section identifies code transformations that might subvert IEC 60559-specified
behavior, and others that do not.
-<a name="F.9.1" href="#F.9.1"><h4>F.9.1 Global transformations</h4></a>
+<h4><a name="F.9.1" href="#F.9.1">F.9.1 Global transformations</a></h4>
<p><!--para 1 -->
Floating-point arithmetic operations and external function calls may entail side effects
which optimization shall honor, at least where the state of the FENV_ACCESS pragma is
/* ... */
for (i = 0; i < n; i++) x + 1;
/* ... */
- }</pre>
+ }
+</pre>
x + 1 might raise floating-point exceptions, so cannot be removed. And since the loop
body might not execute (maybe 0 >= n), x + 1 cannot be moved out of the loop. (Of
course these optimizations are valid if the implementation can rule out the nettlesome
<!--page 529 -->
the preceding loop could be treated as
<pre>
- if (0 < n) x + 1;</pre>
+ if (0 < n) x + 1;
+</pre>
-<a name="F.9.2" href="#F.9.2"><h4>F.9.2 Expression transformations</h4></a>
+<h4><a name="F.9.2" href="#F.9.2">F.9.2 Expression transformations</a></h4>
<p><!--para 1 -->
x/2 <-> x x 0.5 Although similar transformations involving inexact constants
<pre>
generally do not yield numerically equivalent expressions, if the
constants are exact then such transformations can be made on
- IEC 60559 machines and others that round perfectly.</pre>
+ IEC 60559 machines and others that round perfectly.
+</pre>
1 x x and x/1 -> x The expressions 1 x x, x/1, and x are equivalent (on IEC 60559
<pre>
- machines, among others).<sup><a href="#note355"><b>355)</b></a></sup></pre>
+ machines, among others).<sup><a href="#note355"><b>355)</b></a></sup>
+</pre>
x/x -> 1.0 The expressions x/x and 1.0 are not equivalent if x can be zero,
<pre>
- infinite, or NaN.</pre>
+ infinite, or NaN.
+</pre>
x - y <-> x + (-y) The expressions x - y, x + (-y), and (-y) + x are equivalent (on
<pre>
- IEC 60559 machines, among others).</pre>
+ IEC 60559 machines, among others).
+</pre>
x - y <-> -(y - x) The expressions x - y and -(y - x) are not equivalent because 1 - 1
<pre>
- is +0 but -(1 - 1) is -0 (in the default rounding direction).<sup><a href="#note356"><b>356)</b></a></sup></pre>
+ is +0 but -(1 - 1) is -0 (in the default rounding direction).<sup><a href="#note356"><b>356)</b></a></sup>
+</pre>
x - x -> 0.0 The expressions x - x and 0.0 are not equivalent if x is a NaN or
<pre>
- infinite.</pre>
+ infinite.
+</pre>
0 x x -> 0.0 The expressions 0 x x and 0.0 are not equivalent if x is a NaN,
<pre>
- infinite, or -0.</pre>
+ infinite, or -0.
+</pre>
x+0-> x The expressions x + 0 and x are not equivalent if x is -0, because
<pre>
- (-0) + (+0) yields +0 (in the default rounding direction), not -0.</pre>
+ (-0) + (+0) yields +0 (in the default rounding direction), not -0.
+</pre>
x-0-> x (+0) - (+0) yields -0 when rounding is downward (toward -(inf)), but
<pre>
+0 otherwise, and (-0) - (+0) always yields -0; so, if the state of the
FENV_ACCESS pragma is ''off'', promising default rounding, then
- the implementation can replace x - 0 by x, even if x might be zero.</pre>
+ the implementation can replace x - 0 by x, even if x might be zero.
+</pre>
-x <-> 0 - x The expressions -x and 0 - x are not equivalent if x is +0, because
<pre>
-(+0) yields -0, but 0 - (+0) yields +0 (unless rounding is
- downward).</pre>
+ downward).
+</pre>
<!--page 530 -->
Examples include:
<pre>
- 1/(1/ (+-) (inf)) is (+-) (inf)</pre>
+ 1/(1/ (+-) (inf)) is (+-) (inf)
+</pre>
and
<pre>
- conj(csqrt(z)) is csqrt(conj(z)),</pre>
+ conj(csqrt(z)) is csqrt(conj(z)),
+</pre>
for complex z.
</small>
-<a name="F.9.3" href="#F.9.3"><h4>F.9.3 Relational operators</h4></a>
+<h4><a name="F.9.3" href="#F.9.3">F.9.3 Relational operators</a></h4>
<p><!--para 1 -->
x != x -> false The expression x != x is true if x is a NaN.
x = x -> true The expression x = x is false if x is a NaN.
transformation, which would be desirable if extra code were required
to cause the ''invalid'' floating-point exception for unordered cases,
could be performed provided the state of the FENV_ACCESS pragma
- is ''off''.</pre>
+ is ''off''.
+</pre>
The sense of relational operators shall be maintained. This includes handling unordered
cases as expressed by the source code.
<p><!--para 2 -->
if (a < b)
f();
else
- g();</pre>
+ g();
+</pre>
is not equivalent to
<pre>
// calls f and raises ''invalid'' if a and b are unordered
if (a >= b)
g();
else
- f();</pre>
+ f();
+</pre>
nor to
<pre>
// calls f without raising ''invalid'' if a and b are unordered
if (isgreaterequal(a,b))
g();
else
- f();</pre>
+ f();
+</pre>
nor, unless the state of the FENV_ACCESS pragma is ''off'', to
<pre>
// calls g without raising ''invalid'' if a and b are unordered
if (isless(a,b))
f();
else
- g();</pre>
+ g();
+</pre>
but is equivalent to
<!--page 531 -->
<pre>
if (!(a < b))
g();
else
- f();</pre>
+ f();
+</pre>
-<a name="F.9.4" href="#F.9.4"><h4>F.9.4 Constant arithmetic</h4></a>
+<h4><a name="F.9.4" href="#F.9.4">F.9.4 Constant arithmetic</a></h4>
<p><!--para 1 -->
The implementation shall honor floating-point exceptions raised by execution-time
constant arithmetic wherever the state of the FENV_ACCESS pragma is ''on''. (See <a href="#F.8.4">F.8.4</a>
<p><small><a name="note357" href="#note357">357)</a> 0 - 0 yields -0 instead of +0 just when the rounding direction is downward.
</small>
-<a name="F.10" href="#F.10"><h3>F.10 Mathematics <math.h></h3></a>
+<h3><a name="F.10" href="#F.10">F.10 Mathematics <math.h></a></h3>
<p><!--para 1 -->
This subclause contains specifications of <a href="#7.12"><math.h></a> facilities that are particularly suited
for IEC 60559 implementations.
For families of functions, the specifications apply to all of the functions even though only
the principal function is shown. Unless otherwise specified, where the symbol ''(+-)''
occurs in both an argument and the result, the result has the same sign as the argument.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 13 -->
If a function with one or more NaN arguments returns a NaN result, the result should be
the same as one of the NaN arguments (after possible type conversion), except perhaps
avoiding them would be too costly.
</small>
-<a name="F.10.1" href="#F.10.1"><h4>F.10.1 Trigonometric functions</h4></a>
+<h4><a name="F.10.1" href="#F.10.1">F.10.1 Trigonometric functions</a></h4>
-<a name="F.10.1.1" href="#F.10.1.1"><h5>F.10.1.1 The acos functions</h5></a>
+<h5><a name="F.10.1.1" href="#F.10.1.1">F.10.1.1 The acos functions</a></h5>
<p><!--para 1 -->
<ul>
<li> acos(1) returns +0.
| x | > 1.
</ul>
-<a name="F.10.1.2" href="#F.10.1.2"><h5>F.10.1.2 The asin functions</h5></a>
+<h5><a name="F.10.1.2" href="#F.10.1.2">F.10.1.2 The asin functions</a></h5>
<p><!--para 1 -->
<ul>
<li> asin((+-)0) returns (+-)0.
<!--page 533 -->
</ul>
-<a name="F.10.1.3" href="#F.10.1.3"><h5>F.10.1.3 The atan functions</h5></a>
+<h5><a name="F.10.1.3" href="#F.10.1.3">F.10.1.3 The atan functions</a></h5>
<p><!--para 1 -->
<ul>
<li> atan((+-)0) returns (+-)0.
<li> atan((+-)(inf)) returns (+-)pi /2.
</ul>
-<a name="F.10.1.4" href="#F.10.1.4"><h5>F.10.1.4 The atan2 functions</h5></a>
+<h5><a name="F.10.1.4" href="#F.10.1.4">F.10.1.4 The atan2 functions</a></h5>
<p><!--para 1 -->
<ul>
<li> atan2((+-)0, -0) returns (+-)pi .<sup><a href="#note360"><b>360)</b></a></sup>
the ''divide-by-zero'' floating-point exception.
</small>
-<a name="F.10.1.5" href="#F.10.1.5"><h5>F.10.1.5 The cos functions</h5></a>
+<h5><a name="F.10.1.5" href="#F.10.1.5">F.10.1.5 The cos functions</a></h5>
<p><!--para 1 -->
<ul>
<li> cos((+-)0) returns 1.
<li> cos((+-)(inf)) returns a NaN and raises the ''invalid'' floating-point exception.
</ul>
-<a name="F.10.1.6" href="#F.10.1.6"><h5>F.10.1.6 The sin functions</h5></a>
+<h5><a name="F.10.1.6" href="#F.10.1.6">F.10.1.6 The sin functions</a></h5>
<p><!--para 1 -->
<ul>
<li> sin((+-)0) returns (+-)0.
<li> sin((+-)(inf)) returns a NaN and raises the ''invalid'' floating-point exception.
</ul>
-<a name="F.10.1.7" href="#F.10.1.7"><h5>F.10.1.7 The tan functions</h5></a>
+<h5><a name="F.10.1.7" href="#F.10.1.7">F.10.1.7 The tan functions</a></h5>
<p><!--para 1 -->
<ul>
<li> tan((+-)0) returns (+-)0.
<!--page 534 -->
</ul>
-<a name="F.10.2" href="#F.10.2"><h4>F.10.2 Hyperbolic functions</h4></a>
+<h4><a name="F.10.2" href="#F.10.2">F.10.2 Hyperbolic functions</a></h4>
-<a name="F.10.2.1" href="#F.10.2.1"><h5>F.10.2.1 The acosh functions</h5></a>
+<h5><a name="F.10.2.1" href="#F.10.2.1">F.10.2.1 The acosh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> acosh(1) returns +0.
<li> acosh(+(inf)) returns +(inf).
</ul>
-<a name="F.10.2.2" href="#F.10.2.2"><h5>F.10.2.2 The asinh functions</h5></a>
+<h5><a name="F.10.2.2" href="#F.10.2.2">F.10.2.2 The asinh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> asinh((+-)0) returns (+-)0.
<li> asinh((+-)(inf)) returns (+-)(inf).
</ul>
-<a name="F.10.2.3" href="#F.10.2.3"><h5>F.10.2.3 The atanh functions</h5></a>
+<h5><a name="F.10.2.3" href="#F.10.2.3">F.10.2.3 The atanh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> atanh((+-)0) returns (+-)0.
| x | > 1.
</ul>
-<a name="F.10.2.4" href="#F.10.2.4"><h5>F.10.2.4 The cosh functions</h5></a>
+<h5><a name="F.10.2.4" href="#F.10.2.4">F.10.2.4 The cosh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> cosh((+-)0) returns 1.
<li> cosh((+-)(inf)) returns +(inf).
</ul>
-<a name="F.10.2.5" href="#F.10.2.5"><h5>F.10.2.5 The sinh functions</h5></a>
+<h5><a name="F.10.2.5" href="#F.10.2.5">F.10.2.5 The sinh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> sinh((+-)0) returns (+-)0.
<li> sinh((+-)(inf)) returns (+-)(inf).
</ul>
-<a name="F.10.2.6" href="#F.10.2.6"><h5>F.10.2.6 The tanh functions</h5></a>
+<h5><a name="F.10.2.6" href="#F.10.2.6">F.10.2.6 The tanh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> tanh((+-)0) returns (+-)0.
<li> tanh((+-)(inf)) returns (+-)1.
</ul>
-<a name="F.10.3" href="#F.10.3"><h4>F.10.3 Exponential and logarithmic functions</h4></a>
+<h4><a name="F.10.3" href="#F.10.3">F.10.3 Exponential and logarithmic functions</a></h4>
-<a name="F.10.3.1" href="#F.10.3.1"><h5>F.10.3.1 The exp functions</h5></a>
+<h5><a name="F.10.3.1" href="#F.10.3.1">F.10.3.1 The exp functions</a></h5>
<p><!--para 1 -->
<ul>
<li> exp((+-)0) returns 1.
<!--page 535 -->
</ul>
-<a name="F.10.3.2" href="#F.10.3.2"><h5>F.10.3.2 The exp2 functions</h5></a>
+<h5><a name="F.10.3.2" href="#F.10.3.2">F.10.3.2 The exp2 functions</a></h5>
<p><!--para 1 -->
<ul>
<li> exp2((+-)0) returns 1.
<li> exp2(+(inf)) returns +(inf).
</ul>
-<a name="F.10.3.3" href="#F.10.3.3"><h5>F.10.3.3 The expm1 functions</h5></a>
+<h5><a name="F.10.3.3" href="#F.10.3.3">F.10.3.3 The expm1 functions</a></h5>
<p><!--para 1 -->
<ul>
<li> expm1((+-)0) returns (+-)0.
<li> expm1(+(inf)) returns +(inf).
</ul>
-<a name="F.10.3.4" href="#F.10.3.4"><h5>F.10.3.4 The frexp functions</h5></a>
+<h5><a name="F.10.3.4" href="#F.10.3.4">F.10.3.4 The frexp functions</a></h5>
<p><!--para 1 -->
<ul>
<li> frexp((+-)0, exp) returns (+-)0, and stores 0 in the object pointed to by exp.
{
*exp = (value == 0) ? 0 : (int)(1 + logb(value));
return scalbn(value, -(*exp));
- }</pre>
+ }
+</pre>
-<a name="F.10.3.5" href="#F.10.3.5"><h5>F.10.3.5 The ilogb functions</h5></a>
+<h5><a name="F.10.3.5" href="#F.10.3.5">F.10.3.5 The ilogb functions</a></h5>
<p><!--para 1 -->
When the correct result is representable in the range of the return type, the returned value
is exact and is independent of the current rounding direction mode.
unspecified and the ''invalid'' floating-point exception is raised.
<!--page 536 -->
-<a name="F.10.3.6" href="#F.10.3.6"><h5>F.10.3.6 The ldexp functions</h5></a>
+<h5><a name="F.10.3.6" href="#F.10.3.6">F.10.3.6 The ldexp functions</a></h5>
<p><!--para 1 -->
On a binary system, ldexp(x, exp) is equivalent to scalbn(x, exp).
-<a name="F.10.3.7" href="#F.10.3.7"><h5>F.10.3.7 The log functions</h5></a>
+<h5><a name="F.10.3.7" href="#F.10.3.7">F.10.3.7 The log functions</a></h5>
<p><!--para 1 -->
<ul>
<li> log((+-)0) returns -(inf) and raises the ''divide-by-zero'' floating-point exception.
<li> log(+(inf)) returns +(inf).
</ul>
-<a name="F.10.3.8" href="#F.10.3.8"><h5>F.10.3.8 The log10 functions</h5></a>
+<h5><a name="F.10.3.8" href="#F.10.3.8">F.10.3.8 The log10 functions</a></h5>
<p><!--para 1 -->
<ul>
<li> log10((+-)0) returns -(inf) and raises the ''divide-by-zero'' floating-point exception.
<li> log10(+(inf)) returns +(inf).
</ul>
-<a name="F.10.3.9" href="#F.10.3.9"><h5>F.10.3.9 The log1p functions</h5></a>
+<h5><a name="F.10.3.9" href="#F.10.3.9">F.10.3.9 The log1p functions</a></h5>
<p><!--para 1 -->
<ul>
<li> log1p((+-)0) returns (+-)0.
<li> log1p(+(inf)) returns +(inf).
</ul>
-<a name="F.10.3.10" href="#F.10.3.10"><h5>F.10.3.10 The log2 functions</h5></a>
+<h5><a name="F.10.3.10" href="#F.10.3.10">F.10.3.10 The log2 functions</a></h5>
<p><!--para 1 -->
<ul>
<li> log2((+-)0) returns -(inf) and raises the ''divide-by-zero'' floating-point exception.
<li> log2(+(inf)) returns +(inf).
</ul>
-<a name="F.10.3.11" href="#F.10.3.11"><h5>F.10.3.11 The logb functions</h5></a>
+<h5><a name="F.10.3.11" href="#F.10.3.11">F.10.3.11 The logb functions</a></h5>
<p><!--para 1 -->
<ul>
<li> logb((+-)0) returns -(inf) and raises the ''divide-by-zero'' floating-point exception.
The returned value is exact and is independent of the current rounding direction mode.
<!--page 537 -->
-<a name="F.10.3.12" href="#F.10.3.12"><h5>F.10.3.12 The modf functions</h5></a>
+<h5><a name="F.10.3.12" href="#F.10.3.12">F.10.3.12 The modf functions</a></h5>
<p><!--para 1 -->
<ul>
<li> modf((+-)x, iptr) returns a result with the same sign as x.
return copysign(
isinf(value) ? 0.0 :
value - (*iptr), value);
- }</pre>
+ }
+</pre>
-<a name="F.10.3.13" href="#F.10.3.13"><h5>F.10.3.13 The scalbn and scalbln functions</h5></a>
+<h5><a name="F.10.3.13" href="#F.10.3.13">F.10.3.13 The scalbn and scalbln functions</a></h5>
<p><!--para 1 -->
<ul>
<li> scalbn((+-)0, n) returns (+-)0.
independent of the current rounding direction mode.
<!--page 538 -->
-<a name="F.10.4" href="#F.10.4"><h4>F.10.4 Power and absolute value functions</h4></a>
+<h4><a name="F.10.4" href="#F.10.4">F.10.4 Power and absolute value functions</a></h4>
-<a name="F.10.4.1" href="#F.10.4.1"><h5>F.10.4.1 The cbrt functions</h5></a>
+<h5><a name="F.10.4.1" href="#F.10.4.1">F.10.4.1 The cbrt functions</a></h5>
<p><!--para 1 -->
<ul>
<li> cbrt((+-)0) returns (+-)0.
<li> cbrt((+-)(inf)) returns (+-)(inf).
</ul>
-<a name="F.10.4.2" href="#F.10.4.2"><h5>F.10.4.2 The fabs functions</h5></a>
+<h5><a name="F.10.4.2" href="#F.10.4.2">F.10.4.2 The fabs functions</a></h5>
<p><!--para 1 -->
<ul>
<li> fabs((+-)0) returns +0.
<p><!--para 2 -->
The returned value is exact and is independent of the current rounding direction mode.
-<a name="F.10.4.3" href="#F.10.4.3"><h5>F.10.4.3 The hypot functions</h5></a>
+<h5><a name="F.10.4.3" href="#F.10.4.3">F.10.4.3 The hypot functions</a></h5>
<p><!--para 1 -->
<ul>
<li> hypot(x, y), hypot(y, x), and hypot(x, -y) are equivalent.
<li> hypot((+-)(inf), y) returns +(inf), even if y is a NaN.
</ul>
-<a name="F.10.4.4" href="#F.10.4.4"><h5>F.10.4.4 The pow functions</h5></a>
+<h5><a name="F.10.4.4" href="#F.10.4.4">F.10.4.4 The pow functions</a></h5>
<p><!--para 1 -->
<ul>
<li> pow((+-)0, y) returns (+-)(inf) and raises the ''divide-by-zero'' floating-point exception
<li> pow(+(inf), y) returns +(inf) for y > 0.
</ul>
-<a name="F.10.4.5" href="#F.10.4.5"><h5>F.10.4.5 The sqrt functions</h5></a>
+<h5><a name="F.10.4.5" href="#F.10.4.5">F.10.4.5 The sqrt functions</a></h5>
<p><!--para 1 -->
sqrt is fully specified as a basic arithmetic operation in IEC 60559. The returned value
is dependent on the current rounding direction mode.
-<a name="F.10.5" href="#F.10.5"><h4>F.10.5 Error and gamma functions</h4></a>
+<h4><a name="F.10.5" href="#F.10.5">F.10.5 Error and gamma functions</a></h4>
-<a name="F.10.5.1" href="#F.10.5.1"><h5>F.10.5.1 The erf functions</h5></a>
+<h5><a name="F.10.5.1" href="#F.10.5.1">F.10.5.1 The erf functions</a></h5>
<p><!--para 1 -->
<ul>
<li> erf((+-)0) returns (+-)0.
<li> erf((+-)(inf)) returns (+-)1.
</ul>
-<a name="F.10.5.2" href="#F.10.5.2"><h5>F.10.5.2 The erfc functions</h5></a>
+<h5><a name="F.10.5.2" href="#F.10.5.2">F.10.5.2 The erfc functions</a></h5>
<p><!--para 1 -->
<ul>
<li> erfc(-(inf)) returns 2.
<li> erfc(+(inf)) returns +0.
</ul>
-<a name="F.10.5.3" href="#F.10.5.3"><h5>F.10.5.3 The lgamma functions</h5></a>
+<h5><a name="F.10.5.3" href="#F.10.5.3">F.10.5.3 The lgamma functions</a></h5>
<p><!--para 1 -->
<ul>
<li> lgamma(1) returns +0.
<li> lgamma(+(inf)) returns +(inf).
</ul>
-<a name="F.10.5.4" href="#F.10.5.4"><h5>F.10.5.4 The tgamma functions</h5></a>
+<h5><a name="F.10.5.4" href="#F.10.5.4">F.10.5.4 The tgamma functions</a></h5>
<p><!--para 1 -->
<ul>
<li> tgamma((+-)0) returns (+-)(inf) and raises the ''divide-by-zero'' floating-point exception.
<!--page 540 -->
</ul>
-<a name="F.10.6" href="#F.10.6"><h4>F.10.6 Nearest integer functions</h4></a>
+<h4><a name="F.10.6" href="#F.10.6">F.10.6 Nearest integer functions</a></h4>
-<a name="F.10.6.1" href="#F.10.6.1"><h5>F.10.6.1 The ceil functions</h5></a>
+<h5><a name="F.10.6.1" href="#F.10.6.1">F.10.6.1 The ceil functions</a></h5>
<p><!--para 1 -->
<ul>
<li> ceil((+-)0) returns (+-)0.
The returned value is independent of the current rounding direction mode.
<p><!--para 3 -->
The double version of ceil behaves as though implemented by
-<p><!--para 4 -->
<pre>
#include <a href="#7.12"><math.h></a>
#include <a href="#7.6"><fenv.h></a>
result = rint(x); // or nearbyint instead of rint
fesetround(save_round);
return result;
- }</pre>
+ }
+</pre>
+<p><!--para 4 -->
The ceil functions may, but are not required to, raise the ''inexact'' floating-point
exception for finite non-integer arguments, as this implementation does.
-<a name="F.10.6.2" href="#F.10.6.2"><h5>F.10.6.2 The floor functions</h5></a>
+<h5><a name="F.10.6.2" href="#F.10.6.2">F.10.6.2 The floor functions</a></h5>
<p><!--para 1 -->
<ul>
<li> floor((+-)0) returns (+-)0.
not required to, raise the ''inexact'' floating-point exception for finite non-integer
arguments, as that implementation does.
-<a name="F.10.6.3" href="#F.10.6.3"><h5>F.10.6.3 The nearbyint functions</h5></a>
+<h5><a name="F.10.6.3" href="#F.10.6.3">F.10.6.3 The nearbyint functions</a></h5>
<p><!--para 1 -->
The nearbyint functions use IEC 60559 rounding according to the current rounding
direction. They do not raise the ''inexact'' floating-point exception if the result differs in
<!--page 541 -->
</ul>
-<a name="F.10.6.4" href="#F.10.6.4"><h5>F.10.6.4 The rint functions</h5></a>
+<h5><a name="F.10.6.4" href="#F.10.6.4">F.10.6.4 The rint functions</a></h5>
<p><!--para 1 -->
The rint functions differ from the nearbyint functions only in that they do raise the
''inexact'' floating-point exception if the result differs in value from the argument.
-<a name="F.10.6.5" href="#F.10.6.5"><h5>F.10.6.5 The lrint and llrint functions</h5></a>
+<h5><a name="F.10.6.5" href="#F.10.6.5">F.10.6.5 The lrint and llrint functions</a></h5>
<p><!--para 1 -->
The lrint and llrint functions provide floating-to-integer conversion as prescribed
by IEC 60559. They round according to the current rounding direction. If the rounded
exception and the result differs from the argument, they raise the ''inexact'' floating-point
exception.
-<a name="F.10.6.6" href="#F.10.6.6"><h5>F.10.6.6 The round functions</h5></a>
+<h5><a name="F.10.6.6" href="#F.10.6.6">F.10.6.6 The round functions</a></h5>
<p><!--para 1 -->
<ul>
<li> round((+-)0) returns (+-)0.
}
feupdateenv(&save_env);
return result;
- }</pre>
+ }
+</pre>
The round functions may, but are not required to, raise the ''inexact'' floating-point
exception for finite non-integer numeric arguments, as this implementation does.
<!--page 542 -->
-<a name="F.10.6.7" href="#F.10.6.7"><h5>F.10.6.7 The lround and llround functions</h5></a>
+<h5><a name="F.10.6.7" href="#F.10.6.7">F.10.6.7 The lround and llround functions</a></h5>
<p><!--para 1 -->
The lround and llround functions differ from the lrint and llrint functions
with the default rounding direction just in that the lround and llround functions
round halfway cases away from zero and need not raise the ''inexact'' floating-point
exception for non-integer arguments that round to within the range of the return type.
-<a name="F.10.6.8" href="#F.10.6.8"><h5>F.10.6.8 The trunc functions</h5></a>
+<h5><a name="F.10.6.8" href="#F.10.6.8">F.10.6.8 The trunc functions</a></h5>
<p><!--para 1 -->
The trunc functions use IEC 60559 rounding toward zero (regardless of the current
rounding direction). The returned value is exact.
functions may, but are not required to, raise the ''inexact'' floating-point exception for
finite non-integer arguments.
-<a name="F.10.7" href="#F.10.7"><h4>F.10.7 Remainder functions</h4></a>
+<h4><a name="F.10.7" href="#F.10.7">F.10.7 Remainder functions</a></h4>
-<a name="F.10.7.1" href="#F.10.7.1"><h5>F.10.7.1 The fmod functions</h5></a>
+<h5><a name="F.10.7.1" href="#F.10.7.1">F.10.7.1 The fmod functions</a></h5>
<p><!--para 1 -->
<ul>
<li> fmod((+-)0, y) returns (+-)0 for y not zero.
result = remainder(fabs(x), (y = fabs(y)));
if (signbit(result)) result += y;
return copysign(result, x);
- }</pre>
+ }
+</pre>
-<a name="F.10.7.2" href="#F.10.7.2"><h5>F.10.7.2 The remainder functions</h5></a>
+<h5><a name="F.10.7.2" href="#F.10.7.2">F.10.7.2 The remainder functions</a></h5>
<p><!--para 1 -->
The remainder functions are fully specified as a basic arithmetic operation in
IEC 60559.
When subnormal results are supported, the returned value is exact and is independent of
the current rounding direction mode.
-<a name="F.10.7.3" href="#F.10.7.3"><h5>F.10.7.3 The remquo functions</h5></a>
+<h5><a name="F.10.7.3" href="#F.10.7.3">F.10.7.3 The remquo functions</a></h5>
<p><!--para 1 -->
The remquo functions follow the specifications for the remainder functions. They
have no further specifications special to IEC 60559 implementations.
When subnormal results are supported, the returned value is exact and is independent of
the current rounding direction mode.
-<a name="F.10.8" href="#F.10.8"><h4>F.10.8 Manipulation functions</h4></a>
+<h4><a name="F.10.8" href="#F.10.8">F.10.8 Manipulation functions</a></h4>
-<a name="F.10.8.1" href="#F.10.8.1"><h5>F.10.8.1 The copysign functions</h5></a>
+<h5><a name="F.10.8.1" href="#F.10.8.1">F.10.8.1 The copysign functions</a></h5>
<p><!--para 1 -->
copysign is specified in the Appendix to IEC 60559.
<p><!--para 2 -->
The returned value is exact and is independent of the current rounding direction mode.
-<a name="F.10.8.2" href="#F.10.8.2"><h5>F.10.8.2 The nan functions</h5></a>
+<h5><a name="F.10.8.2" href="#F.10.8.2">F.10.8.2 The nan functions</a></h5>
<p><!--para 1 -->
All IEC 60559 implementations support quiet NaNs, in all floating formats.
<p><!--para 2 -->
The returned value is exact and is independent of the current rounding direction mode.
-<a name="F.10.8.3" href="#F.10.8.3"><h5>F.10.8.3 The nextafter functions</h5></a>
+<h5><a name="F.10.8.3" href="#F.10.8.3">F.10.8.3 The nextafter functions</a></h5>
<p><!--para 1 -->
<ul>
<li> nextafter(x, y) raises the ''overflow'' and ''inexact'' floating-point exceptions
Even though underflow or overflow can occur, the returned value is independent of the
current rounding direction mode.
-<a name="F.10.8.4" href="#F.10.8.4"><h5>F.10.8.4 The nexttoward functions</h5></a>
+<h5><a name="F.10.8.4" href="#F.10.8.4">F.10.8.4 The nexttoward functions</a></h5>
<p><!--para 1 -->
No additional requirements beyond those on nextafter.
<p><!--para 2 -->
current rounding direction mode.
<!--page 544 -->
-<a name="F.10.9" href="#F.10.9"><h4>F.10.9 Maximum, minimum, and positive difference functions</h4></a>
+<h4><a name="F.10.9" href="#F.10.9">F.10.9 Maximum, minimum, and positive difference functions</a></h4>
-<a name="F.10.9.1" href="#F.10.9.1"><h5>F.10.9.1 The fdim functions</h5></a>
+<h5><a name="F.10.9.1" href="#F.10.9.1">F.10.9.1 The fdim functions</a></h5>
<p><!--para 1 -->
No additional requirements.
-<a name="F.10.9.2" href="#F.10.9.2"><h5>F.10.9.2 The fmax functions</h5></a>
+<h5><a name="F.10.9.2" href="#F.10.9.2">F.10.9.2 The fmax functions</a></h5>
<p><!--para 1 -->
If just one argument is a NaN, the fmax functions return the other argument (if both
arguments are NaNs, the functions return a NaN).
The body of the fmax function might be<sup><a href="#note361"><b>361)</b></a></sup>
<pre>
{ return (isgreaterequal(x, y) ||
- isnan(y)) ? x : y; }</pre>
+ isnan(y)) ? x : y; }
+</pre>
<h6>footnotes</h6>
<p><small><a name="note361" href="#note361">361)</a> Ideally, fmax would be sensitive to the sign of zero, for example fmax(-0.0, +0.0) would
return +0; however, implementation in software might be impractical.
</small>
-<a name="F.10.9.3" href="#F.10.9.3"><h5>F.10.9.3 The fmin functions</h5></a>
+<h5><a name="F.10.9.3" href="#F.10.9.3">F.10.9.3 The fmin functions</a></h5>
<p><!--para 1 -->
The fmin functions are analogous to the fmax functions (see <a href="#F.10.9.2">F.10.9.2</a>).
<p><!--para 2 -->
The returned value is exact and is independent of the current rounding direction mode.
-<a name="F.10.10" href="#F.10.10"><h4>F.10.10 Floating multiply-add</h4></a>
+<h4><a name="F.10.10" href="#F.10.10">F.10.10 Floating multiply-add</a></h4>
-<a name="F.10.10.1" href="#F.10.10.1"><h5>F.10.10.1 The fma functions</h5></a>
+<h5><a name="F.10.10.1" href="#F.10.10.1">F.10.10.1 The fma functions</a></h5>
<p><!--para 1 -->
<ul>
<li> fma(x, y, z) computes xy + z, correctly rounded once.
<!--page 545 -->
</ul>
-<a name="F.10.11" href="#F.10.11"><h4>F.10.11 Comparison macros</h4></a>
+<h4><a name="F.10.11" href="#F.10.11">F.10.11 Comparison macros</a></h4>
<p><!--para 1 -->
Relational operators and their corresponding comparison macros (<a href="#7.12.14">7.12.14</a>) produce
equivalent result values, even if argument values are represented in wider formats. Thus,
operands of relational operators to their semantic types.
<!--page 546 -->
-<a name="G" href="#G"><h2>Annex G</h2></a>
+<h2><a name="G" href="#G">Annex G</a></h2>
<pre>
(normative)
- IEC 60559-compatible complex arithmetic</pre>
+ IEC 60559-compatible complex arithmetic
+</pre>
-<a name="G.1" href="#G.1"><h3>G.1 Introduction</h3></a>
+<h3><a name="G.1" href="#G.1">G.1 Introduction</a></h3>
<p><!--para 1 -->
This annex supplements <a href="#F">annex F</a> to specify complex arithmetic for compatibility with
IEC 60559 real floating-point arithmetic. An implementation that defines *
to these specifications.
</small>
-<a name="G.2" href="#G.2"><h3>G.2 Types</h3></a>
+<h3><a name="G.2" href="#G.2">G.2 Types</a></h3>
<p><!--para 1 -->
There is a new keyword _Imaginary, which is used to specify imaginary types. It is
used as a type specifier within declaration specifiers in the same way as _Complex is
<p><!--para 5 -->
The imaginary type domain comprises the imaginary types.
-<a name="G.3" href="#G.3"><h3>G.3 Conventions</h3></a>
+<h3><a name="G.3" href="#G.3">G.3 Conventions</a></h3>
<p><!--para 1 -->
A complex or imaginary value with at least one infinite part is regarded as an infinity
(even if its other part is a NaN). A complex or imaginary value is a finite number if each
<!--page 547 -->
-<a name="G.4" href="#G.4"><h3>G.4 Conversions</h3></a>
+<h3><a name="G.4" href="#G.4">G.4 Conversions</a></h3>
-<a name="G.4.1" href="#G.4.1"><h4>G.4.1 Imaginary types</h4></a>
+<h4><a name="G.4.1" href="#G.4.1">G.4.1 Imaginary types</a></h4>
<p><!--para 1 -->
Conversions among imaginary types follow rules analogous to those for real floating
types.
-<a name="G.4.2" href="#G.4.2"><h4>G.4.2 Real and imaginary</h4></a>
+<h4><a name="G.4.2" href="#G.4.2">G.4.2 Real and imaginary</a></h4>
<p><!--para 1 -->
When a value of imaginary type is converted to a real type other than _Bool,<sup><a href="#note363"><b>363)</b></a></sup> the
result is a positive zero.
<p><small><a name="note363" href="#note363">363)</a> See <a href="#6.3.1.2">6.3.1.2</a>.
</small>
-<a name="G.4.3" href="#G.4.3"><h4>G.4.3 Imaginary and complex</h4></a>
+<h4><a name="G.4.3" href="#G.4.3">G.4.3 Imaginary and complex</a></h4>
<p><!--para 1 -->
When a value of imaginary type is converted to a complex type, the real part of the
complex result value is a positive zero and the imaginary part of the complex result value
complex value is discarded and the value of the imaginary part is converted according to
the conversion rules for the corresponding real types.
-<a name="G.5" href="#G.5"><h3>G.5 Binary operators</h3></a>
+<h3><a name="G.5" href="#G.5">G.5 Binary operators</a></h3>
<p><!--para 1 -->
The following subclauses supplement <a href="#6.5">6.5</a> in order to specify the type of the result for an
operation with an imaginary operand.
<!--page 548 -->
-<a name="G.5.1" href="#G.5.1"><h4>G.5.1 Multiplicative operators</h4></a>
+<h4><a name="G.5.1" href="#G.5.1">G.5.1 Multiplicative operators</a></h4>
<h6>Semantics</h6>
<p><!--para 1 -->
If one operand has real type and the other operand has imaginary type, then the result has
If the operands are not both complex, then the result and floating-point exception
behavior of the * operator is defined by the usual mathematical formula:
<pre>
- * u iv u + iv</pre>
+ * u iv u + iv
+</pre>
<pre>
- x xu i(xv) (xu) + i(xv)</pre>
+ x xu i(xv) (xu) + i(xv)
+</pre>
<pre>
- iy i(yu) -yv (-yv) + i(yu)</pre>
+ iy i(yu) -yv (-yv) + i(yu)
+</pre>
-<p><!--para 3 -->
<pre>
- x + iy (xu) + i(yu) (-yv) + i(xv)</pre>
+ x + iy (xu) + i(yu) (-yv) + i(xv)
+</pre>
+<p><!--para 3 -->
If the second operand is not complex, then the result and floating-point exception
behavior of the / operator is defined by the usual mathematical formula:
<pre>
- / u iv</pre>
+ / u iv
+</pre>
<pre>
- x x/u i(-x/v)</pre>
+ x x/u i(-x/v)
+</pre>
<pre>
- iy i(y/u) y/v</pre>
+ iy i(y/u) y/v
+</pre>
-<p><!--para 4 -->
<pre>
- x + iy (x/u) + i(y/u) (y/v) + i(-x/v)</pre>
+ x + iy (x/u) + i(y/u) (y/v) + i(-x/v)
+</pre>
+<p><!--para 4 -->
The * and / operators satisfy the following infinity properties for all real, imaginary, and
complex operands:<sup><a href="#note364"><b>364)</b></a></sup>
<ul>
EXAMPLE 1 Multiplication of double _Complex operands could be implemented as follows. Note
that the imaginary unit I has imaginary type (see <a href="#G.6">G.6</a>).
<!--page 550 -->
-<p><!--para 7 -->
<pre>
#include <a href="#7.12"><math.h></a>
#include <a href="#7.3"><complex.h></a>
}
}
return x + I * y;
- }</pre>
+ }
+</pre>
+<p><!--para 7 -->
This implementation achieves the required treatment of infinities at the cost of only one isnan test in
ordinary (finite) cases. It is less than ideal in that undue overflow and underflow may occur.
<p><!--para 8 -->
EXAMPLE 2 Division of two double _Complex operands could be implemented as follows.
<!--page 551 -->
-<p><!--para 9 -->
<pre>
#include <a href="#7.12"><math.h></a>
#include <a href="#7.3"><complex.h></a>
}
}
return x + I * y;
- }</pre>
+ }
+</pre>
+<p><!--para 9 -->
Scaling the denominator alleviates the main overflow and underflow problem, which is more serious than
for multiplication. In the spirit of the multiplication example above, this code does not defend against
overflow and underflow in the calculation of the numerator. Scaling with the scalbn function, instead of
(at least where the state for CX_LIMITED_RANGE is ''off'').
</small>
-<a name="G.5.2" href="#G.5.2"><h4>G.5.2 Additive operators</h4></a>
+<h4><a name="G.5.2" href="#G.5.2">G.5.2 Additive operators</a></h4>
<h6>Semantics</h6>
<p><!--para 1 -->
If both operands have imaginary type, then the result has imaginary type. (If one operand
In all cases the result and floating-point exception behavior of a + or - operator is defined
by the usual mathematical formula:
<pre>
- + or - u iv u + iv</pre>
+ + or - u iv u + iv
+</pre>
<pre>
- x x(+-)u x (+-) iv (x (+-) u) (+-) iv</pre>
+ x x(+-)u x (+-) iv (x (+-) u) (+-) iv
+</pre>
<pre>
- iy (+-)u + iy i(y (+-) v) (+-)u + i(y (+-) v)</pre>
+ iy (+-)u + iy i(y (+-) v) (+-)u + i(y (+-) v)
+</pre>
<pre>
- x + iy (x (+-) u) + iy x + i(y (+-) v) (x (+-) u) + i(y (+-) v)</pre>
+ x + iy (x (+-) u) + iy x + i(y (+-) v) (x (+-) u) + i(y (+-) v)
+</pre>
-<a name="G.6" href="#G.6"><h3>G.6 Complex arithmetic <complex.h></h3></a>
+<h3><a name="G.6" href="#G.6">G.6 Complex arithmetic <complex.h></a></h3>
<p><!--para 1 -->
The macros
<pre>
- imaginary</pre>
+ imaginary
+</pre>
and
<pre>
- _Imaginary_I</pre>
+ _Imaginary_I
+</pre>
are defined, respectively, as _Imaginary and a constant expression of type const
float _Imaginary with the value of the imaginary unit. The macro
<pre>
- I</pre>
+ I
+</pre>
is defined to be _Imaginary_I (not _Complex_I as stated in <a href="#7.3">7.3</a>). Notwithstanding
the provisions of <a href="#7.1.3">7.1.3</a>, a program may undefine and then perhaps redefine the macro
imaginary.
<p><!--para 6 -->
Each of the functions cabs and carg is specified by a formula in terms of a real
function (whose special cases are covered in <a href="#F">annex F</a>):
-<p><!--para 7 -->
<pre>
cabs(x + iy) = hypot(x, y)
- carg(x + iy) = atan2(y, x)</pre>
+ carg(x + iy) = atan2(y, x)
+</pre>
+<p><!--para 7 -->
Each of the functions casin, catan, ccos, csin, and ctan is specified implicitly by
a formula in terms of other complex functions (whose special cases are specified below):
-<p><!--para 8 -->
<pre>
casin(z) = -i casinh(iz)
catan(z) = -i catanh(iz)
ccos(z) = ccosh(iz)
csin(z) = -i csinh(iz)
- ctan(z) = -i ctanh(iz)</pre>
+ ctan(z) = -i ctanh(iz)
+</pre>
+<p><!--para 8 -->
For the other functions, the following subclauses specify behavior for special cases,
including treatment of the ''invalid'' and ''divide-by-zero'' floating-point exceptions. For
families of functions, the specifications apply to all of the functions even though only the
other part is a NaN.
</small>
-<a name="G.6.1" href="#G.6.1"><h4>G.6.1 Trigonometric functions</h4></a>
+<h4><a name="G.6.1" href="#G.6.1">G.6.1 Trigonometric functions</a></h4>
-<a name="G.6.1.1" href="#G.6.1.1"><h5>G.6.1.1 The cacos functions</h5></a>
+<h5><a name="G.6.1.1" href="#G.6.1.1">G.6.1.1 The cacos functions</a></h5>
<p><!--para 1 -->
<ul>
<li> cacos(conj(z)) = conj(cacos(z)).
<li> cacos(NaN + iNaN) returns NaN + iNaN.
</ul>
-<a name="G.6.2" href="#G.6.2"><h4>G.6.2 Hyperbolic functions</h4></a>
+<h4><a name="G.6.2" href="#G.6.2">G.6.2 Hyperbolic functions</a></h4>
-<a name="G.6.2.1" href="#G.6.2.1"><h5>G.6.2.1 The cacosh functions</h5></a>
+<h5><a name="G.6.2.1" href="#G.6.2.1">G.6.2.1 The cacosh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> cacosh(conj(z)) = conj(cacosh(z)).
<li> cacosh(NaN + iNaN) returns NaN + iNaN.
</ul>
-<a name="G.6.2.2" href="#G.6.2.2"><h5>G.6.2.2 The casinh functions</h5></a>
+<h5><a name="G.6.2.2" href="#G.6.2.2">G.6.2.2 The casinh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> casinh(conj(z)) = conj(casinh(z)) and casinh is odd.
<li> casinh(NaN + iNaN) returns NaN + iNaN.
</ul>
-<a name="G.6.2.3" href="#G.6.2.3"><h5>G.6.2.3 The catanh functions</h5></a>
+<h5><a name="G.6.2.3" href="#G.6.2.3">G.6.2.3 The catanh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> catanh(conj(z)) = conj(catanh(z)) and catanh is odd.
<li> catanh(NaN + iNaN) returns NaN + iNaN.
</ul>
-<a name="G.6.2.4" href="#G.6.2.4"><h5>G.6.2.4 The ccosh functions</h5></a>
+<h5><a name="G.6.2.4" href="#G.6.2.4">G.6.2.4 The ccosh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> ccosh(conj(z)) = conj(ccosh(z)) and ccosh is even.
<li> ccosh(NaN + iNaN) returns NaN + iNaN.
</ul>
-<a name="G.6.2.5" href="#G.6.2.5"><h5>G.6.2.5 The csinh functions</h5></a>
+<h5><a name="G.6.2.5" href="#G.6.2.5">G.6.2.5 The csinh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> csinh(conj(z)) = conj(csinh(z)) and csinh is odd.
<li> csinh(NaN + iNaN) returns NaN + iNaN.
</ul>
-<a name="G.6.2.6" href="#G.6.2.6"><h5>G.6.2.6 The ctanh functions</h5></a>
+<h5><a name="G.6.2.6" href="#G.6.2.6">G.6.2.6 The ctanh functions</a></h5>
<p><!--para 1 -->
<ul>
<li> ctanh(conj(z)) = conj(ctanh(z))and ctanh is odd.
<!--page 557 -->
</ul>
-<a name="G.6.3" href="#G.6.3"><h4>G.6.3 Exponential and logarithmic functions</h4></a>
+<h4><a name="G.6.3" href="#G.6.3">G.6.3 Exponential and logarithmic functions</a></h4>
-<a name="G.6.3.1" href="#G.6.3.1"><h5>G.6.3.1 The cexp functions</h5></a>
+<h5><a name="G.6.3.1" href="#G.6.3.1">G.6.3.1 The cexp functions</a></h5>
<p><!--para 1 -->
<ul>
<li> cexp(conj(z)) = conj(cexp(z)).
<li> cexp(NaN + iNaN) returns NaN + iNaN.
</ul>
-<a name="G.6.3.2" href="#G.6.3.2"><h5>G.6.3.2 The clog functions</h5></a>
+<h5><a name="G.6.3.2" href="#G.6.3.2">G.6.3.2 The clog functions</a></h5>
<p><!--para 1 -->
<ul>
<li> clog(conj(z)) = conj(clog(z)).
<li> clog(NaN + iNaN) returns NaN + iNaN.
</ul>
-<a name="G.6.4" href="#G.6.4"><h4>G.6.4 Power and absolute-value functions</h4></a>
+<h4><a name="G.6.4" href="#G.6.4">G.6.4 Power and absolute-value functions</a></h4>
-<a name="G.6.4.1" href="#G.6.4.1"><h5>G.6.4.1 The cpow functions</h5></a>
+<h5><a name="G.6.4.1" href="#G.6.4.1">G.6.4.1 The cpow functions</a></h5>
<p><!--para 1 -->
The cpow functions raise floating-point exceptions if appropriate for the calculation of
the parts of the result, and may also raise spurious floating-point exceptions.<sup><a href="#note366"><b>366)</b></a></sup>
implementations that treat special cases more carefully.
</small>
-<a name="G.6.4.2" href="#G.6.4.2"><h5>G.6.4.2 The csqrt functions</h5></a>
+<h5><a name="G.6.4.2" href="#G.6.4.2">G.6.4.2 The csqrt functions</a></h5>
<p><!--para 1 -->
<ul>
<li> csqrt(conj(z)) = conj(csqrt(z)).
<!--page 559 -->
</ul>
-<a name="G.7" href="#G.7"><h3>G.7 Type-generic math <tgmath.h></h3></a>
+<h3><a name="G.7" href="#G.7">G.7 Type-generic math <tgmath.h></a></h3>
<p><!--para 1 -->
Type-generic macros that accept complex arguments also accept imaginary arguments. If
an argument is imaginary, the macro expands to an expression whose type is real,
asin(iy) = i asinh(y)
atan(iy) = i atanh(y)
asinh(iy) = i asin(y)
- atanh(iy) = i atan(y)</pre>
+ atanh(iy) = i atan(y)
+</pre>
-<a name="H" href="#H"><h2>Annex H</h2></a>
+<h2><a name="H" href="#H">Annex H</a></h2>
<pre>
(informative)
- Language independent arithmetic</pre>
+ Language independent arithmetic
+</pre>
-<a name="H.1" href="#H.1"><h3>H.1 Introduction</h3></a>
+<h3><a name="H.1" href="#H.1">H.1 Introduction</a></h3>
<p><!--para 1 -->
This annex documents the extent to which the C language supports the ISO/IEC 10967-1
standard for language-independent arithmetic (LIA-1). LIA-1 is more general than
IEC 60559 (<a href="#F">annex F</a>) in that it covers integer and diverse floating-point arithmetics.
-<a name="H.2" href="#H.2"><h3>H.2 Types</h3></a>
+<h3><a name="H.2" href="#H.2">H.2 Types</a></h3>
<p><!--para 1 -->
The relevant C arithmetic types meet the requirements of LIA-1 types if an
implementation adds notification of exceptional arithmetic operations and meets the 1
unit in the last place (ULP) accuracy requirement (LIA-1 subclause <a href="#5.2.8">5.2.8</a>).
-<a name="H.2.1" href="#H.2.1"><h4>H.2.1 Boolean type</h4></a>
+<h4><a name="H.2.1" href="#H.2.1">H.2.1 Boolean type</a></h4>
<p><!--para 1 -->
The LIA-1 data type Boolean is implemented by the C data type bool with values of
true and false, all from <a href="#7.18"><stdbool.h></a>.
-<a name="H.2.2" href="#H.2.2"><h4>H.2.2 Integer types</h4></a>
+<h4><a name="H.2.2" href="#H.2.2">H.2.2 Integer types</a></h4>
<p><!--para 1 -->
The signed C integer types int, long int, long long int, and the corresponding
unsigned types are compatible with LIA-1. If an implementation adds support for the
The parameters for the integer data types can be accessed by the following:
maxint INT_MAX, LONG_MAX, LLONG_MAX, UINT_MAX, ULONG_MAX,
<pre>
- ULLONG_MAX</pre>
+ ULLONG_MAX
+</pre>
minint INT_MIN, LONG_MIN, LLONG_MIN
<p><!--para 3 -->
The parameter ''bounded'' is always true, and is not provided. The parameter ''minint''
is always 0 for the unsigned types, and is not provided for those types.
<!--page 561 -->
-<a name="H.2.2.1" href="#H.2.2.1"><h5>H.2.2.1 Integer operations</h5></a>
+<h5><a name="H.2.2.1" href="#H.2.2.1">H.2.2.1 Integer operations</a></h5>
<p><!--para 1 -->
The integer operations on integer types are the following:
addI x + y
geqI x >= y
where x and y are expressions of the same integer type.
-<a name="H.2.3" href="#H.2.3"><h4>H.2.3 Floating-point types</h4></a>
+<h4><a name="H.2.3" href="#H.2.3">H.2.3 Floating-point types</a></h4>
<p><!--para 1 -->
The C floating-point types float, double, and long double are compatible with
LIA-1. If an implementation adds support for the LIA-1 exceptional values
operations (see <a href="#F">annex F</a>) along with IEC 60559 status flags and traps has LIA-1
conformant types.
-<a name="H.2.3.1" href="#H.2.3.1"><h5>H.2.3.1 Floating-point parameters</h5></a>
+<h5><a name="H.2.3.1" href="#H.2.3.1">H.2.3.1 Floating-point parameters</a></h5>
<p><!--para 1 -->
The parameters for a floating point data type can be accessed by the following:
r FLT_RADIX
epsilon FLT_EPSILON, DBL_EPSILON, LDBL_EPSILON
rnd_style FLT_ROUNDS
-<a name="H.2.3.2" href="#H.2.3.2"><h5>H.2.3.2 Floating-point operations</h5></a>
+<h5><a name="H.2.3.2" href="#H.2.3.2">H.2.3.2 Floating-point operations</a></h5>
<p><!--para 1 -->
The floating-point operations on floating-point types are the following:
addF x + y
exponentF 1.f+logbf(x), 1.0+logb(x), 1.L+logbl(x)
scaleF scalbnf(x, n), scalbn(x, n), scalbnl(x, n),
<pre>
- scalblnf(x, li), scalbln(x, li), scalblnl(x, li)</pre>
+ scalblnf(x, li), scalbln(x, li), scalblnl(x, li)
+</pre>
intpartF modff(x, &y), modf(x, &y), modfl(x, &y)
fractpartF modff(x, &y), modf(x, &y), modfl(x, &y)
eqF x == y
where x and y are expressions of the same floating point type, n is of type int, and li
is of type long int.
-<a name="H.2.3.3" href="#H.2.3.3"><h5>H.2.3.3 Rounding styles</h5></a>
+<h5><a name="H.2.3.3" href="#H.2.3.3">H.2.3.3 Rounding styles</a></h5>
<p><!--para 1 -->
The C Standard requires all floating types to use the same radix and rounding style, so
that only one identifier for each is provided to map to LIA-1.
provided that an implementation extends FLT_ROUNDS to cover the rounding style used
in all relevant LIA-1 operations, not just addition as in C.
-<a name="H.2.4" href="#H.2.4"><h4>H.2.4 Type conversions</h4></a>
+<h4><a name="H.2.4" href="#H.2.4">H.2.4 Type conversions</a></h4>
<p><!--para 1 -->
The LIA-1 type conversions are the following type casts:
cvtI' -> I (int)i, (long int)i, (long long int)i,
<pre>
(unsigned int)i, (unsigned long int)i,
- (unsigned long long int)i</pre>
+ (unsigned long long int)i
+</pre>
cvtF -> I (int)x, (long int)x, (long long int)x,
<pre>
(unsigned int)x, (unsigned long int)x,
- (unsigned long long int)x</pre>
+ (unsigned long long int)x
+</pre>
cvtI -> F (float)i, (double)i, (long double)i
cvtF' -> F (float)x, (double)x, (long double)x
<p><!--para 2 -->
implementation uses round-to-nearest.
<!--page 564 -->
-<a name="H.3" href="#H.3"><h3>H.3 Notification</h3></a>
+<h3><a name="H.3" href="#H.3">H.3 Notification</a></h3>
<p><!--para 1 -->
Notification is the process by which a user or program is informed that an exceptional
arithmetic operation has occurred. C's operations are compatible with LIA-1 in that C
allows an implementation to cause a notification to occur when any arithmetic operation
returns an exceptional value as defined in LIA-1 clause 5.
-<a name="H.3.1" href="#H.3.1"><h4>H.3.1 Notification alternatives</h4></a>
+<h4><a name="H.3.1" href="#H.3.1">H.3.1 Notification alternatives</a></h4>
<p><!--para 1 -->
LIA-1 requires at least the following two alternatives for handling of notifications:
setting indicators or trap-and-terminate. LIA-1 allows a third alternative: trap-and-
math library function calls. User-provided signal handlers for SIGFPE allow for trap-
and-resume behavior with the same constraint.
-<a name="H.3.1.1" href="#H.3.1.1"><h5>H.3.1.1 Indicators</h5></a>
+<h5><a name="H.3.1.1" href="#H.3.1.1">H.3.1.1 Indicators</a></h5>
<p><!--para 1 -->
C's <a href="#7.6"><fenv.h></a> status flags are compatible with the LIA-1 indicators.
<p><!--para 2 -->
This documentation makes that distinction because <a href="#7.6"><fenv.h></a> covers only the floating-
point indicators.
-<a name="H.3.1.2" href="#H.3.1.2"><h5>H.3.1.2 Traps</h5></a>
+<h5><a name="H.3.1.2" href="#H.3.1.2">H.3.1.2 Traps</a></h5>
<p><!--para 1 -->
C is compatible with LIA-1's trap requirements for arithmetic operations, but not for
math library functions (which are not permitted to invoke a user's signal handler for
it) or trap-and-resume, at the programmer's option.
<!--page 566 -->
-<a name="I" href="#I"><h2>Annex I</h2></a>
-<p><!--para 1 -->
+<h2><a name="I" href="#I">Annex I</a></h2>
<pre>
(informative)
- Common warnings</pre>
+ Common warnings
+</pre>
+<p><!--para 1 -->
An implementation may generate warnings in many situations, none of which are
specified as part of this International Standard. The following are a few of the more
common situations.
<!--page 568 -->
</ul>
-<a name="J" href="#J"><h2>Annex J</h2></a>
-<p><!--para 1 -->
+<h2><a name="J" href="#J">Annex J</a></h2>
<pre>
(informative)
- Portability issues</pre>
+ Portability issues
+</pre>
+<p><!--para 1 -->
This annex collects some information about portability that appears in this International
Standard.
-<a name="J.1" href="#J.1"><h3>J.1 Unspecified behavior</h3></a>
+<h3><a name="J.1" href="#J.1">J.1 Unspecified behavior</a></h3>
<p><!--para 1 -->
The following are unspecified:
<ul>
<a href="#G.6.2.4">G.6.2.4</a>, <a href="#G.6.2.5">G.6.2.5</a>, <a href="#G.6.2.6">G.6.2.6</a>, <a href="#G.6.3.1">G.6.3.1</a>, <a href="#G.6.4.2">G.6.4.2</a>).
</ul>
-<a name="J.2" href="#J.2"><h3>J.2 Undefined behavior</h3></a>
+<h3><a name="J.2" href="#J.2">J.2 Undefined behavior</a></h3>
<p><!--para 1 -->
The behavior is undefined in the following circumstances:
<ul>
(<a href="#7.29.3.2.1">7.29.3.2.1</a>).
</ul>
-<a name="J.3" href="#J.3"><h3>J.3 Implementation-defined behavior</h3></a>
+<h3><a name="J.3" href="#J.3">J.3 Implementation-defined behavior</a></h3>
<p><!--para 1 -->
A conforming implementation is required to document its choice of behavior in each of
the areas listed in this subclause. The following are implementation-defined:
<!--page 585 -->
-<a name="J.3.1" href="#J.3.1"><h4>J.3.1 Translation</h4></a>
+<h4><a name="J.3.1" href="#J.3.1">J.3.1 Translation</a></h4>
<p><!--para 1 -->
<ul>
<li> How a diagnostic is identified (<a href="#3.10">3.10</a>, <a href="#5.1.1.3">5.1.1.3</a>).
retained or replaced by one space character in translation phase 3 (<a href="#5.1.1.2">5.1.1.2</a>).
</ul>
-<a name="J.3.2" href="#J.3.2"><h4>J.3.2 Environment</h4></a>
+<h4><a name="J.3.2" href="#J.3.2">J.3.2 Environment</a></h4>
<p><!--para 1 -->
<ul>
<li> The mapping between physical source file multibyte characters and the source
<li> The manner of execution of the string by the system function (<a href="#7.22.4.8">7.22.4.8</a>).
</ul>
-<a name="J.3.3" href="#J.3.3"><h4>J.3.3 Identifiers</h4></a>
+<h4><a name="J.3.3" href="#J.3.3">J.3.3 Identifiers</a></h4>
<p><!--para 1 -->
<ul>
<li> Which additional multibyte characters may appear in identifiers and their
<!--page 586 -->
</ul>
-<a name="J.3.4" href="#J.3.4"><h4>J.3.4 Characters</h4></a>
+<h4><a name="J.3.4" href="#J.3.4">J.3.4 Characters</a></h4>
<p><!--para 1 -->
<ul>
<li> The number of bits in a byte (<a href="#3.6">3.6</a>).
<!--page 587 -->
</ul>
-<a name="J.3.5" href="#J.3.5"><h4>J.3.5 Integers</h4></a>
+<h4><a name="J.3.5" href="#J.3.5">J.3.5 Integers</a></h4>
<p><!--para 1 -->
<ul>
<li> Any extended integer types that exist in the implementation (<a href="#6.2.5">6.2.5</a>).
<li> The results of some bitwise operations on signed integers (<a href="#6.5">6.5</a>).
</ul>
-<a name="J.3.6" href="#J.3.6"><h4>J.3.6 Floating point</h4></a>
+<h4><a name="J.3.6" href="#J.3.6">J.3.6 Floating point</a></h4>
<p><!--para 1 -->
<ul>
<li> The accuracy of the floating-point operations and of the library functions in
<!--page 588 -->
</ul>
-<a name="J.3.7" href="#J.3.7"><h4>J.3.7 Arrays and pointers</h4></a>
+<h4><a name="J.3.7" href="#J.3.7">J.3.7 Arrays and pointers</a></h4>
<p><!--para 1 -->
<ul>
<li> The result of converting a pointer to an integer or vice versa (<a href="#6.3.2.3">6.3.2.3</a>).
(<a href="#6.5.6">6.5.6</a>).
</ul>
-<a name="J.3.8" href="#J.3.8"><h4>J.3.8 Hints</h4></a>
+<h4><a name="J.3.8" href="#J.3.8">J.3.8 Hints</a></h4>
<p><!--para 1 -->
<ul>
<li> The extent to which suggestions made by using the register storage-class
effective (<a href="#6.7.4">6.7.4</a>).
</ul>
-<a name="J.3.9" href="#J.3.9"><h4>J.3.9 Structures, unions, enumerations, and bit-fields</h4></a>
+<h4><a name="J.3.9" href="#J.3.9">J.3.9 Structures, unions, enumerations, and bit-fields</a></h4>
<p><!--para 1 -->
<ul>
<li> Whether a ''plain'' int bit-field is treated as a signed int bit-field or as an
<li> The integer type compatible with each enumerated type (<a href="#6.7.2.2">6.7.2.2</a>).
</ul>
-<a name="J.3.10" href="#J.3.10"><h4>J.3.10 Qualifiers</h4></a>
+<h4><a name="J.3.10" href="#J.3.10">J.3.10 Qualifiers</a></h4>
<p><!--para 1 -->
<ul>
<li> What constitutes an access to an object that has volatile-qualified type (<a href="#6.7.3">6.7.3</a>).
</ul>
-<a name="J.3.11" href="#J.3.11"><h4>J.3.11 Preprocessing directives</h4></a>
+<h4><a name="J.3.11" href="#J.3.11">J.3.11 Preprocessing directives</a></h4>
<p><!--para 1 -->
<ul>
<li> The locations within #pragma directives where header name preprocessing tokens
time of translation are not available (<a href="#6.10.8.1">6.10.8.1</a>).
</ul>
-<a name="J.3.12" href="#J.3.12"><h4>J.3.12 Library functions</h4></a>
+<h4><a name="J.3.12" href="#J.3.12">J.3.12 Library functions</a></h4>
<p><!--para 1 -->
<ul>
<li> Any library facilities available to a freestanding program, other than the minimal set
<!--page 592 -->
</ul>
-<a name="J.3.13" href="#J.3.13"><h4>J.3.13 Architecture</h4></a>
+<h4><a name="J.3.13" href="#J.3.13">J.3.13 Architecture</a></h4>
<p><!--para 1 -->
<ul>
<li> The values or expressions assigned to the macros specified in the headers
<li> The value of the result of the sizeof and alignof operators (<a href="#6.5.3.4">6.5.3.4</a>).
</ul>
-<a name="J.4" href="#J.4"><h3>J.4 Locale-specific behavior</h3></a>
+<h3><a name="J.4" href="#J.4">J.4 Locale-specific behavior</a></h3>
<p><!--para 1 -->
The following characteristics of a hosted environment are locale-specific and are required
to be documented by the implementation:
<li> Character classifications that are supported by the iswctype function (<a href="#7.29.1">7.29.1</a>).
</ul>
-<a name="J.5" href="#J.5"><h3>J.5 Common extensions</h3></a>
+<h3><a name="J.5" href="#J.5">J.5 Common extensions</a></h3>
<p><!--para 1 -->
The following extensions are widely used in many systems, but are not portable to all
implementations. The inclusion of any extension that may cause a strictly conforming
extensions are new keywords, extra library functions declared in standard headers, or
predefined macros with names that do not begin with an underscore.
-<a name="J.5.1" href="#J.5.1"><h4>J.5.1 Environment arguments</h4></a>
+<h4><a name="J.5.1" href="#J.5.1">J.5.1 Environment arguments</a></h4>
<p><!--para 1 -->
In a hosted environment, the main function receives a third argument, char *envp[],
that points to a null-terminated array of pointers to char, each of which points to a string
that provides information about the environment for this execution of the program
(<a href="#5.1.2.2.1">5.1.2.2.1</a>).
-<a name="J.5.2" href="#J.5.2"><h4>J.5.2 Specialized identifiers</h4></a>
+<h4><a name="J.5.2" href="#J.5.2">J.5.2 Specialized identifiers</a></h4>
<p><!--para 1 -->
Characters other than the underscore _, letters, and digits, that are not part of the basic
source character set (such as the dollar sign $, or characters in national character sets)
may appear in an identifier (<a href="#6.4.2">6.4.2</a>).
-<a name="J.5.3" href="#J.5.3"><h4>J.5.3 Lengths and cases of identifiers</h4></a>
+<h4><a name="J.5.3" href="#J.5.3">J.5.3 Lengths and cases of identifiers</a></h4>
<p><!--para 1 -->
All characters in identifiers (with or without external linkage) are significant (<a href="#6.4.2">6.4.2</a>).
-<a name="J.5.4" href="#J.5.4"><h4>J.5.4 Scopes of identifiers</h4></a>
+<h4><a name="J.5.4" href="#J.5.4">J.5.4 Scopes of identifiers</a></h4>
<p><!--para 1 -->
A function identifier, or the identifier of an object the declaration of which contains the
keyword extern, has file scope (<a href="#6.2.1">6.2.1</a>).
-<a name="J.5.5" href="#J.5.5"><h4>J.5.5 Writable string literals</h4></a>
+<h4><a name="J.5.5" href="#J.5.5">J.5.5 Writable string literals</a></h4>
<p><!--para 1 -->
String literals are modifiable (in which case, identical string literals should denote distinct
objects) (<a href="#6.4.5">6.4.5</a>).
<!--page 594 -->
-<a name="J.5.6" href="#J.5.6"><h4>J.5.6 Other arithmetic types</h4></a>
+<h4><a name="J.5.6" href="#J.5.6">J.5.6 Other arithmetic types</a></h4>
<p><!--para 1 -->
Additional arithmetic types, such as __int128 or double double, and their
appropriate conversions are defined (<a href="#6.2.5">6.2.5</a>, <a href="#6.3.1">6.3.1</a>). Additional floating types may have
more range or precision than long double, may be used for evaluating expressions of
other floating types, and may be used to define float_t or double_t.
-<a name="J.5.7" href="#J.5.7"><h4>J.5.7 Function pointer casts</h4></a>
+<h4><a name="J.5.7" href="#J.5.7">J.5.7 Function pointer casts</a></h4>
<p><!--para 1 -->
A pointer to an object or to void may be cast to a pointer to a function, allowing data to
be invoked as a function (<a href="#6.5.4">6.5.4</a>).
A pointer to a function may be cast to a pointer to an object or to void, allowing a
function to be inspected or modified (for example, by a debugger) (<a href="#6.5.4">6.5.4</a>).
-<a name="J.5.8" href="#J.5.8"><h4>J.5.8 Extended bit-field types</h4></a>
+<h4><a name="J.5.8" href="#J.5.8">J.5.8 Extended bit-field types</a></h4>
<p><!--para 1 -->
A bit-field may be declared with a type other than _Bool, unsigned int, or
signed int, with an appropriate maximum width (<a href="#6.7.2.1">6.7.2.1</a>).
-<a name="J.5.9" href="#J.5.9"><h4>J.5.9 The fortran keyword</h4></a>
+<h4><a name="J.5.9" href="#J.5.9">J.5.9 The fortran keyword</a></h4>
<p><!--para 1 -->
The fortran function specifier may be used in a function declaration to indicate that
calls suitable for FORTRAN should be generated, or that a different representation for the
external name is to be generated (<a href="#6.7.4">6.7.4</a>).
-<a name="J.5.10" href="#J.5.10"><h4>J.5.10 The asm keyword</h4></a>
+<h4><a name="J.5.10" href="#J.5.10">J.5.10 The asm keyword</a></h4>
<p><!--para 1 -->
The asm keyword may be used to insert assembly language directly into the translator
output (<a href="#6.8">6.8</a>). The most common implementation is via a statement of the form:
<pre>
- asm ( character-string-literal );</pre>
+ asm ( character-string-literal );
+</pre>
-<a name="J.5.11" href="#J.5.11"><h4>J.5.11 Multiple external definitions</h4></a>
+<h4><a name="J.5.11" href="#J.5.11">J.5.11 Multiple external definitions</a></h4>
<p><!--para 1 -->
There may be more than one external definition for the identifier of an object, with or
without the explicit use of the keyword extern; if the definitions disagree, or more than
one is initialized, the behavior is undefined (<a href="#6.9.2">6.9.2</a>).
-<a name="J.5.12" href="#J.5.12"><h4>J.5.12 Predefined macro names</h4></a>
+<h4><a name="J.5.12" href="#J.5.12">J.5.12 Predefined macro names</a></h4>
<p><!--para 1 -->
Macro names that do not begin with an underscore, describing the translation and
execution environments, are defined by the implementation before translation begins
(<a href="#6.10.8">6.10.8</a>).
<!--page 595 -->
-<a name="J.5.13" href="#J.5.13"><h4>J.5.13 Floating-point status flags</h4></a>
+<h4><a name="J.5.13" href="#J.5.13">J.5.13 Floating-point status flags</a></h4>
<p><!--para 1 -->
If any floating-point status flags are set on normal termination after all calls to functions
registered by the atexit function have been made (see <a href="#7.22.4.4">7.22.4.4</a>), the implementation
writes some diagnostics indicating the fact to the stderr stream, if it is still open,
-<a name="J.5.14" href="#J.5.14"><h4>J.5.14 Extra arguments for signal handlers</h4></a>
+<h4><a name="J.5.14" href="#J.5.14">J.5.14 Extra arguments for signal handlers</a></h4>
<p><!--para 1 -->
Handlers for specific signals are called with extra arguments in addition to the signal
number (<a href="#7.14.1.1">7.14.1.1</a>).
-<a name="J.5.15" href="#J.5.15"><h4>J.5.15 Additional stream types and file-opening modes</h4></a>
+<h4><a name="J.5.15" href="#J.5.15">J.5.15 Additional stream types and file-opening modes</a></h4>
<p><!--para 1 -->
Additional mappings from files to streams are supported (<a href="#7.21.2">7.21.2</a>).
<p><!--para 2 -->
Additional file-opening modes may be specified by characters appended to the mode
argument of the fopen function (<a href="#7.21.5.3">7.21.5.3</a>).
-<a name="J.5.16" href="#J.5.16"><h4>J.5.16 Defined file position indicator</h4></a>
+<h4><a name="J.5.16" href="#J.5.16">J.5.16 Defined file position indicator</a></h4>
<p><!--para 1 -->
The file position indicator is decremented by each successful call to the ungetc or
ungetwc function for a text stream, except if its value was zero before a call (<a href="#7.21.7.10">7.21.7.10</a>,
<a href="#7.28.3.10">7.28.3.10</a>).
-<a name="J.5.17" href="#J.5.17"><h4>J.5.17 Math error reporting</h4></a>
+<h4><a name="J.5.17" href="#J.5.17">J.5.17 Math error reporting</a></h4>
<p><!--para 1 -->
Functions declared in <a href="#7.3"><complex.h></a> and <a href="#7.12"><math.h></a> raise SIGFPE to report errors
instead of, or in addition to, setting errno or raising floating-point exceptions (<a href="#7.3">7.3</a>,
<a href="#7.12">7.12</a>).
<!--page 596 -->
-<a name="K" href="#K"><h2>Annex K</h2></a>
+<h2><a name="K" href="#K">Annex K</a></h2>
<pre>
(normative)
- Bounds-checking interfaces</pre>
+ Bounds-checking interfaces
+</pre>
-<a name="K.1" href="#K.1"><h3>K.1 Background</h3></a>
+<h3><a name="K.1" href="#K.1">K.1 Background</a></h3>
<p><!--para 1 -->
Traditionally, the C Library has contained many functions that trust the programmer to
provide output character arrays big enough to hold the result being produced. Not only
change if the function is called again, perhaps by another thread.
<!--page 597 -->
-<a name="K.2" href="#K.2"><h3>K.2 Scope</h3></a>
+<h3><a name="K.2" href="#K.2">K.2 Scope</a></h3>
<p><!--para 1 -->
This annex specifies a series of optional extensions that can be useful in the mitigation of
security vulnerabilities in programs, and comprise new functions, macros, and types
specifications.
</small>
-<a name="K.3" href="#K.3"><h3>K.3 Library</h3></a>
+<h3><a name="K.3" href="#K.3">K.3 Library</a></h3>
-<a name="K.3.1" href="#K.3.1"><h4>K.3.1 Introduction</h4></a>
+<h4><a name="K.3.1" href="#K.3.1">K.3.1 Introduction</a></h4>
-<a name="K.3.1.1" href="#K.3.1.1"><h5>K.3.1.1 Standard headers</h5></a>
+<h5><a name="K.3.1.1" href="#K.3.1.1">K.3.1.1 Standard headers</a></h5>
<p><!--para 1 -->
The functions, macros, and types declared or defined in <a href="#K.3">K.3</a> and its subclauses are not
declared or defined by their respective headers if __STDC_WANT_LIB_EXT1__ is
implementation is not conforming.
</small>
-<a name="K.3.1.2" href="#K.3.1.2"><h5>K.3.1.2 Reserved identifiers</h5></a>
+<h5><a name="K.3.1.2" href="#K.3.1.2">K.3.1.2 Reserved identifiers</a></h5>
<p><!--para 1 -->
Each macro name in any of the following subclauses is reserved for use as specified if it
is defined by any of its associated headers when included; unless explicitly stated
as a macro name and as an identifier with file scope in the same name space if it is
defined by any of its associated headers when included.
-<a name="K.3.1.3" href="#K.3.1.3"><h5>K.3.1.3 Use of errno</h5></a>
+<h5><a name="K.3.1.3" href="#K.3.1.3">K.3.1.3 Use of errno</a></h5>
<p><!--para 1 -->
An implementation may set errno for the functions defined in this annex, but is not
required to.
-<a name="K.3.1.4" href="#K.3.1.4"><h5>K.3.1.4 Runtime-constraint violations</h5></a>
+<h5><a name="K.3.1.4" href="#K.3.1.4">K.3.1.4 Runtime-constraint violations</a></h5>
<p><!--para 1 -->
Most functions in this annex include as part of their specification a list of runtime-
constraints. These runtime-constraints are requirements on the program using the
from the definition of undefined behavior.
</small>
-<a name="K.3.2" href="#K.3.2"><h4>K.3.2 Errors <errno.h></h4></a>
+<h4><a name="K.3.2" href="#K.3.2">K.3.2 Errors <errno.h></a></h4>
<p><!--para 1 -->
The header <a href="#7.5"><errno.h></a> defines a type.
<p><!--para 2 -->
The type is
<pre>
- errno_t</pre>
+ errno_t
+</pre>
which is type int.<sup><a href="#note371"><b>371)</b></a></sup>
<h6>footnotes</h6>
errno might be declared as having the return type errno_t.
</small>
-<a name="K.3.3" href="#K.3.3"><h4>K.3.3 Common definitions <stddef.h></h4></a>
+<h4><a name="K.3.3" href="#K.3.3">K.3.3 Common definitions <stddef.h></a></h4>
<p><!--para 1 -->
The header <a href="#7.19"><stddef.h></a> defines a type.
<p><!--para 2 -->
The type is
<pre>
- rsize_t</pre>
+ rsize_t
+</pre>
which is the type size_t.<sup><a href="#note372"><b>372)</b></a></sup>
<h6>footnotes</h6>
<p><small><a name="note372" href="#note372">372)</a> See the description of the RSIZE_MAX macro in <a href="#7.20"><stdint.h></a>.
</small>
-<a name="K.3.4" href="#K.3.4"><h4>K.3.4 Integer types <stdint.h></h4></a>
+<h4><a name="K.3.4" href="#K.3.4">K.3.4 Integer types <stdint.h></a></h4>
<p><!--para 1 -->
The header <a href="#7.20"><stdint.h></a> defines a macro.
<p><!--para 2 -->
The macro is
<pre>
- RSIZE_MAX</pre>
+ RSIZE_MAX
+</pre>
which expands to a value<sup><a href="#note373"><b>373)</b></a></sup> of type size_t. Functions that have parameters of type
rsize_t consider it a runtime-constraint violation if the values of those parameters are
greater than RSIZE_MAX.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 3 -->
Extremely large object sizes are frequently a sign that an object's size was calculated
incorrectly. For example, negative numbers appear as very large positive numbers when
<p><small><a name="note373" href="#note373">373)</a> The macro RSIZE_MAX need not expand to a constant expression.
</small>
-<a name="K.3.5" href="#K.3.5"><h4>K.3.5 Input/output <stdio.h></h4></a>
+<h4><a name="K.3.5" href="#K.3.5">K.3.5 Input/output <stdio.h></a></h4>
<p><!--para 1 -->
The header <a href="#7.21"><stdio.h></a> defines several macros and two types.
<p><!--para 2 -->
The macros are
<pre>
- L_tmpnam_s</pre>
+ L_tmpnam_s
+</pre>
which expands to an integer constant expression that is the size needed for an array of
char large enough to hold a temporary file name string generated by the tmpnam_s
function;
<pre>
- TMP_MAX_S</pre>
+ TMP_MAX_S
+</pre>
which expands to an integer constant expression that is the maximum number of unique
file names that can be generated by the tmpnam_s function.
<p><!--para 3 -->
The types are
<pre>
- errno_t</pre>
+ errno_t
+</pre>
which is type int; and
<pre>
- rsize_t</pre>
+ rsize_t
+</pre>
which is the type size_t.
-<a name="K.3.5.1" href="#K.3.5.1"><h5>K.3.5.1 Operations on files</h5></a>
+<h5><a name="K.3.5.1" href="#K.3.5.1">K.3.5.1 Operations on files</a></h5>
-<a name="K.3.5.1.1" href="#K.3.5.1.1"><h5>K.3.5.1.1 The tmpfile_s function</h5></a>
+<h5><a name="K.3.5.1.1" href="#K.3.5.1.1">K.3.5.1.1 The tmpfile_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
- errno_t tmpfile_s(FILE * restrict * restrict streamptr);</pre>
+ errno_t tmpfile_s(FILE * restrict * restrict streamptr);
+</pre>
Runtime-constraints
<p><!--para 2 -->
streamptr shall not be a null pointer.
If the file was created successfully, then the pointer to FILE pointed to by streamptr
will be set to the pointer to the object controlling the opened file. Otherwise, the pointer
to FILE pointed to by streamptr will be set to a null pointer.
- Recommended practice
+<h6>Recommended practice</h6>
It should be possible to open at least TMP_MAX_S temporary files during the lifetime of
the program (this limit may be shared with tmpnam_s) and there should be no limit on
the number simultaneously open other than this limit and any limit on the number of open
The tmpfile_s function returns zero if it created the file. If it did not create the file or
there was a runtime-constraint violation, tmpfile_s returns a nonzero value.
-<a name="K.3.5.1.2" href="#K.3.5.1.2"><h5>K.3.5.1.2 The tmpnam_s function</h5></a>
+<h5><a name="K.3.5.1.2" href="#K.3.5.1.2">K.3.5.1.2 The tmpnam_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
- errno_t tmpnam_s(char *s, rsize_t maxsize);</pre>
+ errno_t tmpnam_s(char *s, rsize_t maxsize);
+</pre>
Runtime-constraints
<p><!--para 2 -->
s shall not be a null pointer. maxsize shall be less than or equal to RSIZE_MAX.
<p><!--para 6 -->
The implementation shall behave as if no library function except tmpnam calls the
tmpnam_s function.<sup><a href="#note375"><b>375)</b></a></sup>
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 7 -->
After a program obtains a file name using the tmpnam_s function and before the
program creates a file with that name, the possibility exists that someone else may create
<p><!--para 9 -->
Otherwise, the tmpnam_s function writes the string in the array pointed to by s and
returns zero.
- Environmental limits
+<h6>Environmental limits</h6>
<p><!--para 10 -->
The value of the macro TMP_MAX_S shall be at least 25.
convention for temporary files), but this is not required.
</small>
-<a name="K.3.5.2" href="#K.3.5.2"><h5>K.3.5.2 File access functions</h5></a>
+<h5><a name="K.3.5.2" href="#K.3.5.2">K.3.5.2 File access functions</a></h5>
-<a name="K.3.5.2.1" href="#K.3.5.2.1"><h5>K.3.5.2.1 The fopen_s function</h5></a>
+<h5><a name="K.3.5.2.1" href="#K.3.5.2.1">K.3.5.2.1 The fopen_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
errno_t fopen_s(FILE * restrict * restrict streamptr,
const char * restrict filename,
- const char * restrict mode);</pre>
+ const char * restrict mode);
+</pre>
Runtime-constraints
<p><!--para 2 -->
None of streamptr, filename, or mode shall be a null pointer.
with the character 'w' or 'a' may be preceded by the character 'u', see below:
uw truncate to zero length or create text file for writing, default
<pre>
- permissions</pre>
+ permissions
+</pre>
uwx create text file for writing, default permissions
ua append; open or create text file for writing at end-of-file, default
<pre>
- permissions</pre>
+ permissions
+</pre>
uwb truncate to zero length or create binary file for writing, default
<pre>
- permissions</pre>
+ permissions
+</pre>
uwbx create binary file for writing, default permissions
uab append; open or create binary file for writing at end-of-file, default
<pre>
- permissions</pre>
+ permissions
+</pre>
uw+ truncate to zero length or create text file for update, default
<pre>
- permissions</pre>
+ permissions
+</pre>
uw+x create text file for update, default permissions
ua+ append; open or create text file for update, writing at end-of-file,
<pre>
- default permissions</pre>
+ default permissions
+</pre>
uw+b or uwb+ truncate to zero length or create binary file for update, default
<pre>
- permissions</pre>
+ permissions
+</pre>
uw+bx or uwb+x create binary file for update, default permissions
ua+b or uab+ append; open or create binary file for update, writing at end-of-file,
-<p><!--para 6 -->
<pre>
- default permissions</pre>
+ default permissions
+</pre>
+<p><!--para 6 -->
Opening a file with exclusive mode ('x' as the last character in the mode argument)
fails if the file already exists or cannot be created.
<p><!--para 7 -->
<p><small><a name="note376" href="#note376">376)</a> These are the same permissions that the file would have been created with by fopen.
</small>
-<a name="K.3.5.2.2" href="#K.3.5.2.2"><h5>K.3.5.2.2 The freopen_s function</h5></a>
+<h5><a name="K.3.5.2.2" href="#K.3.5.2.2">K.3.5.2.2 The freopen_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
errno_t freopen_s(FILE * restrict * restrict newstreamptr,
const char * restrict filename,
const char * restrict mode,
- FILE * restrict stream);</pre>
+ FILE * restrict stream);
+</pre>
Runtime-constraints
<p><!--para 2 -->
None of newstreamptr, mode, and stream shall be a null pointer.
there was a runtime-constraint violation, freopen_s returns a nonzero value.
<!--page 605 -->
-<a name="K.3.5.3" href="#K.3.5.3"><h5>K.3.5.3 Formatted input/output functions</h5></a>
+<h5><a name="K.3.5.3" href="#K.3.5.3">K.3.5.3 Formatted input/output functions</a></h5>
<p><!--para 1 -->
Unless explicitly stated otherwise, if the execution of a function described in this
subclause causes copying to take place between objects that overlap, the objects take on
unspecified values.
-<a name="K.3.5.3.1" href="#K.3.5.3.1"><h5>K.3.5.3.1 The fprintf_s function</h5></a>
+<h5><a name="K.3.5.3.1" href="#K.3.5.3.1">K.3.5.3.1 The fprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
int fprintf_s(FILE * restrict stream,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither stream nor format shall be a null pointer. The %n specifier<sup><a href="#note377"><b>377)</b></a></sup> (modified or
constraint violation.
</small>
-<a name="K.3.5.3.2" href="#K.3.5.3.2"><h5>K.3.5.3.2 The fscanf_s function</h5></a>
+<h5><a name="K.3.5.3.2" href="#K.3.5.3.2">K.3.5.3.2 The fscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
int fscanf_s(FILE * restrict stream,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither stream nor format shall be a null pointer. Any argument indirected though in
#include <a href="#7.21"><stdio.h></a>
/* ... */
int n, i; float x; char name[50];
- n = fscanf_s(stdin, "%d%f%s", &i, &x, name, (rsize_t) 50);</pre>
+ n = fscanf_s(stdin, "%d%f%s", &i, &x, name, (rsize_t) 50);
+</pre>
with the input line:
<pre>
- 25 54.32E-1 thompson</pre>
+ 25 54.32E-1 thompson
+</pre>
will assign to n the value 3, to i the value 25, to x the value 5.432, and to name the sequence
thompson\0.
#include <a href="#7.21"><stdio.h></a>
/* ... */
int n; char s[5];
- n = fscanf_s(stdin, "%s", s, sizeof s);</pre>
+ n = fscanf_s(stdin, "%s", s, sizeof s);
+</pre>
with the input line:
<pre>
- hello</pre>
+ hello
+</pre>
will assign to n the value 0 since a matching failure occurred because the sequence hello\0 requires an
array of six characters to store it.
compatible with rsize_t.
</small>
-<a name="K.3.5.3.3" href="#K.3.5.3.3"><h5>K.3.5.3.3 The printf_s function</h5></a>
+<h5><a name="K.3.5.3.3" href="#K.3.5.3.3">K.3.5.3.3 The printf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
- int printf_s(const char * restrict format, ...);</pre>
+ int printf_s(const char * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
format shall not be a null pointer. The %n specifier<sup><a href="#note381"><b>381)</b></a></sup> (modified or not by flags, field
format string was %%n.
</small>
-<a name="K.3.5.3.4" href="#K.3.5.3.4"><h5>K.3.5.3.4 The scanf_s function</h5></a>
+<h5><a name="K.3.5.3.4" href="#K.3.5.3.4">K.3.5.3.4 The scanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
- int scanf_s(const char * restrict format, ...);</pre>
+ int scanf_s(const char * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
format shall not be a null pointer. Any argument indirected though in order to store
scanf_s function returns the number of input items assigned, which can be fewer than
provided for, or even zero, in the event of an early matching failure.
-<a name="K.3.5.3.5" href="#K.3.5.3.5"><h5>K.3.5.3.5 The snprintf_s function</h5></a>
+<h5><a name="K.3.5.3.5" href="#K.3.5.3.5">K.3.5.3.5 The snprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
int snprintf_s(char * restrict s, rsize_t n,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. n shall neither equal zero nor be greater
format string was %%n.
</small>
-<a name="K.3.5.3.6" href="#K.3.5.3.6"><h5>K.3.5.3.6 The sprintf_s function</h5></a>
+<h5><a name="K.3.5.3.6" href="#K.3.5.3.6">K.3.5.3.6 The sprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
int sprintf_s(char * restrict s, rsize_t n,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. n shall neither equal zero nor be greater
format string was %%n.
</small>
-<a name="K.3.5.3.7" href="#K.3.5.3.7"><h5>K.3.5.3.7 The sscanf_s function</h5></a>
+<h5><a name="K.3.5.3.7" href="#K.3.5.3.7">K.3.5.3.7 The sscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
int sscanf_s(const char * restrict s,
- const char * restrict format, ...);</pre>
+ const char * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. Any argument indirected though in order
provided for, or even zero, in the event of an early matching failure.
<!--page 611 -->
-<a name="K.3.5.3.8" href="#K.3.5.3.8"><h5>K.3.5.3.8 The vfprintf_s function</h5></a>
+<h5><a name="K.3.5.3.8" href="#K.3.5.3.8">K.3.5.3.8 The vfprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vfprintf_s(FILE * restrict stream,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither stream nor format shall be a null pointer. The %n specifier<sup><a href="#note384"><b>384)</b></a></sup> (modified or
format string was %%n.
</small>
-<a name="K.3.5.3.9" href="#K.3.5.3.9"><h5>K.3.5.3.9 The vfscanf_s function</h5></a>
+<h5><a name="K.3.5.3.9" href="#K.3.5.3.9">K.3.5.3.9 The vfscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vfscanf_s(FILE * restrict stream,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
indeterminate.
</small>
-<a name="K.3.5.3.10" href="#K.3.5.3.10"><h5>K.3.5.3.10 The vprintf_s function</h5></a>
+<h5><a name="K.3.5.3.10" href="#K.3.5.3.10">K.3.5.3.10 The vprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
#include <a href="#7.21"><stdio.h></a>
int vprintf_s(const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
format shall not be a null pointer. The %n specifier<sup><a href="#note386"><b>386)</b></a></sup> (modified or not by flags, field
format string was %%n.
</small>
-<a name="K.3.5.3.11" href="#K.3.5.3.11"><h5>K.3.5.3.11 The vscanf_s function</h5></a>
+<h5><a name="K.3.5.3.11" href="#K.3.5.3.11">K.3.5.3.11 The vscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
#include <a href="#7.21"><stdio.h></a>
int vscanf_s(const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
format shall not be a null pointer. Any argument indirected though in order to store
indeterminate.
</small>
-<a name="K.3.5.3.12" href="#K.3.5.3.12"><h5>K.3.5.3.12 The vsnprintf_s function</h5></a>
+<h5><a name="K.3.5.3.12" href="#K.3.5.3.12">K.3.5.3.12 The vsnprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vsnprintf_s(char * restrict s, rsize_t n,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. n shall neither equal zero nor be greater
format string was %%n.
</small>
-<a name="K.3.5.3.13" href="#K.3.5.3.13"><h5>K.3.5.3.13 The vsprintf_s function</h5></a>
+<h5><a name="K.3.5.3.13" href="#K.3.5.3.13">K.3.5.3.13 The vsprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vsprintf_s(char * restrict s, rsize_t n,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. n shall neither equal zero nor be greater
format string was %%n.
</small>
-<a name="K.3.5.3.14" href="#K.3.5.3.14"><h5>K.3.5.3.14 The vsscanf_s function</h5></a>
+<h5><a name="K.3.5.3.14" href="#K.3.5.3.14">K.3.5.3.14 The vsscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
int vsscanf_s(const char * restrict s,
const char * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. Any argument indirected though in order
indeterminate.
</small>
-<a name="K.3.5.4" href="#K.3.5.4"><h5>K.3.5.4 Character input/output functions</h5></a>
+<h5><a name="K.3.5.4" href="#K.3.5.4">K.3.5.4 Character input/output functions</a></h5>
-<a name="K.3.5.4.1" href="#K.3.5.4.1"><h5>K.3.5.4.1 The gets_s function</h5></a>
+<h5><a name="K.3.5.4.1" href="#K.3.5.4.1">K.3.5.4.1 The gets_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.21"><stdio.h></a>
- char *gets_s(char *s, rsize_t n);</pre>
+ char *gets_s(char *s, rsize_t n);
+</pre>
If end-of-file is encountered and no characters have been read into the array, or if a read
error occurs during the operation, then s[0] is set to the null character, and the other
elements of s take unspecified values.
- Recommended practice
+<h6>Recommended practice</h6>
<p><!--para 6 -->
The fgets function allows properly-written programs to safely process input lines too
long to store in the result array. In general this requires that callers of fgets pay
expect such a relationship.
</small>
-<a name="K.3.6" href="#K.3.6"><h4>K.3.6 General utilities <stdlib.h></h4></a>
+<h4><a name="K.3.6" href="#K.3.6">K.3.6 General utilities <stdlib.h></a></h4>
<p><!--para 1 -->
The header <a href="#7.22"><stdlib.h></a> defines three types.
<p><!--para 2 -->
The types are
<pre>
- errno_t</pre>
+ errno_t
+</pre>
which is type int; and
<pre>
- rsize_t</pre>
+ rsize_t
+</pre>
which is the type size_t; and
<pre>
- constraint_handler_t</pre>
+ constraint_handler_t
+</pre>
which has the following definition
<pre>
typedef void (*constraint_handler_t)(
const char * restrict msg,
void * restrict ptr,
- errno_t error);</pre>
+ errno_t error);
+</pre>
-<a name="K.3.6.1" href="#K.3.6.1"><h5>K.3.6.1 Runtime-constraint handling</h5></a>
+<h5><a name="K.3.6.1" href="#K.3.6.1">K.3.6.1 Runtime-constraint handling</a></h5>
-<a name="K.3.6.1.1" href="#K.3.6.1.1"><h5>K.3.6.1.1 The set_constraint_handler_s function</h5></a>
+<h5><a name="K.3.6.1.1" href="#K.3.6.1.1">K.3.6.1.1 The set_constraint_handler_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.22"><stdlib.h></a>
constraint_handler_t set_constraint_handler_s(
- constraint_handler_t handler);</pre>
+ constraint_handler_t handler);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The set_constraint_handler_s function sets the runtime-constraint handler to
pointer argument, a pointer to the implementation default handler is returned (not NULL).
</small>
-<a name="K.3.6.1.2" href="#K.3.6.1.2"><h5>K.3.6.1.2 The abort_handler_s function</h5></a>
+<h5><a name="K.3.6.1.2" href="#K.3.6.1.2">K.3.6.1.2 The abort_handler_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
void abort_handler_s(
const char * restrict msg,
void * restrict ptr,
- errno_t error);</pre>
+ errno_t error);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A pointer to the abort_handler_s function shall be a suitable argument to the
<p><small><a name="note393" href="#note393">393)</a> Many implementations invoke a debugger when the abort function is called.
</small>
-<a name="K.3.6.1.3" href="#K.3.6.1.3"><h5>K.3.6.1.3 The ignore_handler_s function</h5></a>
+<h5><a name="K.3.6.1.3" href="#K.3.6.1.3">K.3.6.1.3 The ignore_handler_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
void ignore_handler_s(
const char * restrict msg,
void * restrict ptr,
- errno_t error);</pre>
+ errno_t error);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
A pointer to the ignore_handler_s function shall be a suitable argument to the
library function returns a nonzero errno_t).
</small>
-<a name="K.3.6.2" href="#K.3.6.2"><h5>K.3.6.2 Communication with the environment</h5></a>
+<h5><a name="K.3.6.2" href="#K.3.6.2">K.3.6.2 Communication with the environment</a></h5>
-<a name="K.3.6.2.1" href="#K.3.6.2.1"><h5>K.3.6.2.1 The getenv_s function</h5></a>
+<h5><a name="K.3.6.2.1" href="#K.3.6.2.1">K.3.6.2.1 The getenv_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
errno_t getenv_s(size_t * restrict len,
char * restrict value, rsize_t maxsize,
- const char * restrict name);</pre>
+ const char * restrict name);
+</pre>
Runtime-constraints
<p><!--para 2 -->
name shall not be a null pointer. maxsize shall neither equal zero nor be greater than
The getenv_s function returns zero if the specified name is found and the associated
string was successfully stored in value. Otherwise, a nonzero value is returned.
-<a name="K.3.6.3" href="#K.3.6.3"><h5>K.3.6.3 Searching and sorting utilities</h5></a>
+<h5><a name="K.3.6.3" href="#K.3.6.3">K.3.6.3 Searching and sorting utilities</a></h5>
<p><!--para 1 -->
These utilities make use of a comparison function to search or sort arrays of unspecified
type. Where an argument declared as size_t nmemb specifies the length of the array
<pre>
((char *)p - (char *)base) % size == 0
(char *)p >= (char *)base
- (char *)p < (char *)base + nmemb * size</pre>
+ (char *)p < (char *)base + nmemb * size
+</pre>
</small>
-<a name="K.3.6.3.1" href="#K.3.6.3.1"><h5>K.3.6.3.1 The bsearch_s function</h5></a>
+<h5><a name="K.3.6.3.1" href="#K.3.6.3.1">K.3.6.3.1 The bsearch_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
rsize_t nmemb, rsize_t size,
int (*compar)(const void *k, const void *y,
void *context),
- void *context);</pre>
+ void *context);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither nmemb nor size shall be greater than RSIZE_MAX. If nmemb is not equal to
example, it might specify a collating sequence used by the comparison function.
</small>
-<a name="K.3.6.3.2" href="#K.3.6.3.2"><h5>K.3.6.3.2 The qsort_s function</h5></a>
+<h5><a name="K.3.6.3.2" href="#K.3.6.3.2">K.3.6.3.2 The qsort_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
errno_t qsort_s(void *base, rsize_t nmemb, rsize_t size,
int (*compar)(const void *x, const void *y,
void *context),
- void *context);</pre>
+ void *context);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither nmemb nor size shall be greater than RSIZE_MAX. If nmemb is not equal to
example, it might specify a collating sequence used by the comparison function.
</small>
-<a name="K.3.6.4" href="#K.3.6.4"><h5>K.3.6.4 Multibyte/wide character conversion functions</h5></a>
+<h5><a name="K.3.6.4" href="#K.3.6.4">K.3.6.4 Multibyte/wide character conversion functions</a></h5>
<p><!--para 1 -->
The behavior of the multibyte character functions is affected by the LC_CTYPE category
of the current locale. For a state-dependent encoding, each function is placed into its
character codes, but are grouped with an adjacent multibyte character.
</small>
-<a name="K.3.6.4.1" href="#K.3.6.4.1"><h5>K.3.6.4.1 The wctomb_s function</h5></a>
+<h5><a name="K.3.6.4.1" href="#K.3.6.4.1">K.3.6.4.1 The wctomb_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
errno_t wctomb_s(int * restrict status,
char * restrict s,
rsize_t smax,
- wchar_t wc);</pre>
+ wchar_t wc);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Let n denote the number of bytes needed to represent the multibyte character
The wctomb_s function returns zero if successful, and a nonzero value if there was a
runtime-constraint violation or wc did not correspond to a valid multibyte character.
-<a name="K.3.6.5" href="#K.3.6.5"><h5>K.3.6.5 Multibyte/wide string conversion functions</h5></a>
+<h5><a name="K.3.6.5" href="#K.3.6.5">K.3.6.5 Multibyte/wide string conversion functions</a></h5>
<p><!--para 1 -->
The behavior of the multibyte string functions is affected by the LC_CTYPE category of
the current locale.
-<a name="K.3.6.5.1" href="#K.3.6.5.1"><h5>K.3.6.5.1 The mbstowcs_s function</h5></a>
+<h5><a name="K.3.6.5.1" href="#K.3.6.5.1">K.3.6.5.1 The mbstowcs_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
errno_t mbstowcs_s(size_t * restrict retval,
wchar_t * restrict dst, rsize_t dstmax,
- const char * restrict src, rsize_t len);</pre>
+ const char * restrict src, rsize_t len);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither retval nor src shall be a null pointer. If dst is not a null pointer, then
terminating null character did not occur where required.
</small>
-<a name="K.3.6.5.2" href="#K.3.6.5.2"><h5>K.3.6.5.2 The wcstombs_s function</h5></a>
+<h5><a name="K.3.6.5.2" href="#K.3.6.5.2">K.3.6.5.2 The wcstombs_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.22"><stdlib.h></a>
errno_t wcstombs_s(size_t * restrict retval,
char * restrict dst, rsize_t dstmax,
- const wchar_t * restrict src, rsize_t len);</pre>
+ const wchar_t * restrict src, rsize_t len);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither retval nor src shall be a null pointer. If dst is not a null pointer, then
runtime-constraint violation.
</small>
-<a name="K.3.7" href="#K.3.7"><h4>K.3.7 String handling <string.h></h4></a>
+<h4><a name="K.3.7" href="#K.3.7">K.3.7 String handling <string.h></a></h4>
<p><!--para 1 -->
The header <a href="#7.23"><string.h></a> defines two types.
<p><!--para 2 -->
The types are
<pre>
- errno_t</pre>
+ errno_t
+</pre>
which is type int; and
<pre>
- rsize_t</pre>
+ rsize_t
+</pre>
which is the type size_t.
-<a name="K.3.7.1" href="#K.3.7.1"><h5>K.3.7.1 Copying functions</h5></a>
+<h5><a name="K.3.7.1" href="#K.3.7.1">K.3.7.1 Copying functions</a></h5>
-<a name="K.3.7.1.1" href="#K.3.7.1.1"><h5>K.3.7.1.1 The memcpy_s function</h5></a>
+<h5><a name="K.3.7.1.1" href="#K.3.7.1.1">K.3.7.1.1 The memcpy_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.23"><string.h></a>
errno_t memcpy_s(void * restrict s1, rsize_t s1max,
- const void * restrict s2, rsize_t n);</pre>
+ const void * restrict s2, rsize_t n);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s1 nor s2 shall be a null pointer. Neither s1max nor n shall be greater than
Otherwise, a nonzero value is returned.
<!--page 629 -->
-<a name="K.3.7.1.2" href="#K.3.7.1.2"><h5>K.3.7.1.2 The memmove_s function</h5></a>
+<h5><a name="K.3.7.1.2" href="#K.3.7.1.2">K.3.7.1.2 The memmove_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.23"><string.h></a>
errno_t memmove_s(void *s1, rsize_t s1max,
- const void *s2, rsize_t n);</pre>
+ const void *s2, rsize_t n);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s1 nor s2 shall be a null pointer. Neither s1max nor n shall be greater than
The memmove_s function returns zero if there was no runtime-constraint violation.
Otherwise, a nonzero value is returned.
-<a name="K.3.7.1.3" href="#K.3.7.1.3"><h5>K.3.7.1.3 The strcpy_s function</h5></a>
+<h5><a name="K.3.7.1.3" href="#K.3.7.1.3">K.3.7.1.3 The strcpy_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
errno_t strcpy_s(char * restrict s1,
rsize_t s1max,
- const char * restrict s2);</pre>
+ const char * restrict s2);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s1 nor s2 shall be a null pointer. s1max shall not be greater than RSIZE_MAX.
within the array pointed to by s1 and that the result in s1 is null terminated.
</small>
-<a name="K.3.7.1.4" href="#K.3.7.1.4"><h5>K.3.7.1.4 The strncpy_s function</h5></a>
+<h5><a name="K.3.7.1.4" href="#K.3.7.1.4">K.3.7.1.4 The strncpy_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
errno_t strncpy_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2,
- rsize_t n);</pre>
+ rsize_t n);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s1 nor s2 shall be a null pointer. Neither s1max nor n shall be greater than
int r1, r2, r3;
r1 = strncpy_s(dst1, 6, src1, 100);
r2 = strncpy_s(dst2, 5, src2, 7);
- r3 = strncpy_s(dst3, 5, src2, 4);</pre>
+ r3 = strncpy_s(dst3, 5, src2, 4);
+</pre>
The first call will assign to r1 the value zero and to dst1 the sequence hello\0.
The second call will assign to r2 a nonzero value and to dst2 the sequence \0.
The third call will assign to r3 the value zero and to dst3 the sequence good\0.
within the array pointed to by s1 and that the result in s1 is null terminated.
</small>
-<a name="K.3.7.2" href="#K.3.7.2"><h5>K.3.7.2 Concatenation functions</h5></a>
+<h5><a name="K.3.7.2" href="#K.3.7.2">K.3.7.2 Concatenation functions</a></h5>
-<a name="K.3.7.2.1" href="#K.3.7.2.1"><h5>K.3.7.2.1 The strcat_s function</h5></a>
+<h5><a name="K.3.7.2.1" href="#K.3.7.2.1">K.3.7.2.1 The strcat_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.23"><string.h></a>
errno_t strcat_s(char * restrict s1,
rsize_t s1max,
- const char * restrict s2);</pre>
+ const char * restrict s2);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Let m denote the value s1max - strnlen_s(s1, s1max) upon entry to
appended to the string pointed to by s1 and that the result in s1 is null terminated.
</small>
-<a name="K.3.7.2.2" href="#K.3.7.2.2"><h5>K.3.7.2.2 The strncat_s function</h5></a>
+<h5><a name="K.3.7.2.2" href="#K.3.7.2.2">K.3.7.2.2 The strncat_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
errno_t strncat_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2,
- rsize_t n);</pre>
+ rsize_t n);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Let m denote the value s1max - strnlen_s(s1, s1max) upon entry to
r1 = strncat_s(s1, 100, s5, 1000);
r2 = strncat_s(s2, 6, "", 1);
r3 = strncat_s(s3, 6, "X", 2);
- r4 = strncat_s(s4, 7, "defghijklmn", 3);</pre>
+ r4 = strncat_s(s4, 7, "defghijklmn", 3);
+</pre>
After the first call r1 will have the value zero and s1 will contain the sequence goodbye\0.
appended to the string pointed to by s1 and that the result in s1 is null terminated.
</small>
-<a name="K.3.7.3" href="#K.3.7.3"><h5>K.3.7.3 Search functions</h5></a>
+<h5><a name="K.3.7.3" href="#K.3.7.3">K.3.7.3 Search functions</a></h5>
-<a name="K.3.7.3.1" href="#K.3.7.3.1"><h5>K.3.7.3.1 The strtok_s function</h5></a>
+<h5><a name="K.3.7.3.1" href="#K.3.7.3.1">K.3.7.3.1 The strtok_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
char *strtok_s(char * restrict s1,
rsize_t * restrict s1max,
const char * restrict s2,
- char ** restrict ptr);</pre>
+ char ** restrict ptr);
+</pre>
Runtime-constraints
<p><!--para 2 -->
None of s1max, s2, or ptr shall be a null pointer. If s1 is a null pointer, then *ptr
t = strtok_s(NULL, &max1, ",", &ptr1); // t points to the token "??b"
t = strtok_s(str2, &max2, " \t", &ptr2); // t is a null pointer
t = strtok_s(NULL, &max1, "#,", &ptr1); // t points to the token "c"
- t = strtok_s(NULL, &max1, "?", &ptr1); // t is a null pointer</pre>
+ t = strtok_s(NULL, &max1, "?", &ptr1); // t is a null pointer
+</pre>
-<a name="K.3.7.4" href="#K.3.7.4"><h5>K.3.7.4 Miscellaneous functions</h5></a>
+<h5><a name="K.3.7.4" href="#K.3.7.4">K.3.7.4 Miscellaneous functions</a></h5>
-<a name="K.3.7.4.1" href="#K.3.7.4.1"><h5>K.3.7.4.1 The memset_s function</h5></a>
+<h5><a name="K.3.7.4.1" href="#K.3.7.4.1">K.3.7.4.1 The memset_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.23"><string.h></a>
- errno_t memset_s(void *s, rsize_t smax, int c, rsize_t n)</pre>
+ errno_t memset_s(void *s, rsize_t smax, int c, rsize_t n)
+</pre>
Runtime-constraints
<p><!--para 2 -->
s shall not be a null pointer. Neither smax nor n shall be greater than RSIZE_MAX. n
The memset_s function returns zero if there was no runtime-constraint violation.
Otherwise, a nonzero value is returned.
-<a name="K.3.7.4.2" href="#K.3.7.4.2"><h5>K.3.7.4.2 The strerror_s function</h5></a>
+<h5><a name="K.3.7.4.2" href="#K.3.7.4.2">K.3.7.4.2 The strerror_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.23"><string.h></a>
errno_t strerror_s(char *s, rsize_t maxsize,
- errno_t errnum);</pre>
+ errno_t errnum);
+</pre>
Runtime-constraints
<p><!--para 2 -->
s shall not be a null pointer. maxsize shall not be greater than RSIZE_MAX.
function returns a nonzero value.
<!--page 637 -->
-<a name="K.3.7.4.3" href="#K.3.7.4.3"><h5>K.3.7.4.3 The strerrorlen_s function</h5></a>
+<h5><a name="K.3.7.4.3" href="#K.3.7.4.3">K.3.7.4.3 The strerrorlen_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.23"><string.h></a>
- size_t strerrorlen_s(errno_t errnum);</pre>
+ size_t strerrorlen_s(errno_t errnum);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strerrorlen_s function calculates the length of the (untruncated) locale-specific
The strerrorlen_s function returns the number of characters (not including the null
character) in the full message string.
-<a name="K.3.7.4.4" href="#K.3.7.4.4"><h5>K.3.7.4.4 The strnlen_s function</h5></a>
+<h5><a name="K.3.7.4.4" href="#K.3.7.4.4">K.3.7.4.4 The strnlen_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.23"><string.h></a>
- size_t strnlen_s(const char *s, size_t maxsize);</pre>
+ size_t strnlen_s(const char *s, size_t maxsize);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The strnlen_s function computes the length of the string pointed to by s.
strnlen_s useful in algorithms that gracefully handle such exceptional data.
</small>
-<a name="K.3.8" href="#K.3.8"><h4>K.3.8 Date and time <time.h></h4></a>
+<h4><a name="K.3.8" href="#K.3.8">K.3.8 Date and time <time.h></a></h4>
<p><!--para 1 -->
The header <a href="#7.26"><time.h></a> defines two types.
<p><!--para 2 -->
The types are
<pre>
- errno_t</pre>
+ errno_t
+</pre>
which is type int; and
<pre>
- rsize_t</pre>
+ rsize_t
+</pre>
which is the type size_t.
-<a name="K.3.8.1" href="#K.3.8.1"><h5>K.3.8.1 Components of time</h5></a>
+<h5><a name="K.3.8.1" href="#K.3.8.1">K.3.8.1 Components of time</a></h5>
<p><!--para 1 -->
A broken-down time is normalized if the values of the members of the tm structure are in
their normal rages.<sup><a href="#note415"><b>415)</b></a></sup>
<p><small><a name="note415" href="#note415">415)</a> The normal ranges are defined in <a href="#7.26.1">7.26.1</a>.
</small>
-<a name="K.3.8.2" href="#K.3.8.2"><h5>K.3.8.2 Time conversion functions</h5></a>
+<h5><a name="K.3.8.2" href="#K.3.8.2">K.3.8.2 Time conversion functions</a></h5>
<p><!--para 1 -->
Like the strftime function, the asctime_s and ctime_s functions do not return a
pointer to a static object, and other library functions are permitted to call them.
-<a name="K.3.8.2.1" href="#K.3.8.2.1"><h5>K.3.8.2.1 The asctime_s function</h5></a>
+<h5><a name="K.3.8.2.1" href="#K.3.8.2.1">K.3.8.2.1 The asctime_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.26"><time.h></a>
errno_t asctime_s(char *s, rsize_t maxsize,
- const struct tm *timeptr);</pre>
+ const struct tm *timeptr);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor timeptr shall be a null pointer. maxsize shall not be less than 26 and
<!--page 639 -->
form
<pre>
- Sun Sep 16 01:03:52 1973\n\0</pre>
+ Sun Sep 16 01:03:52 1973\n\0
+</pre>
The fields making up this string are (in order):
<ol>
<li> The name of the day of the week represented by timeptr->tm_wday using the
<li> The character new line.
<li> The null character.
</ol>
- Recommended practice
+<h6>Recommended practice</h6>
The strftime function allows more flexible formatting and supports locale-specific
behavior. If you do not require the exact form of the result string produced by the
asctime_s function, consider using the strftime function instead.
into the array pointed to by s. Otherwise, it returns a nonzero value.
<!--page 640 -->
-<a name="K.3.8.2.2" href="#K.3.8.2.2"><h5>K.3.8.2.2 The ctime_s function</h5></a>
+<h5><a name="K.3.8.2.2" href="#K.3.8.2.2">K.3.8.2.2 The ctime_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.26"><time.h></a>
errno_t ctime_s(char *s, rsize_t maxsize,
- const time_t *timer);</pre>
+ const time_t *timer);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor timer shall be a null pointer. maxsize shall not be less than 26 and
The ctime_s function converts the calendar time pointed to by timer to local time in
the form of a string. It is equivalent to
<pre>
- asctime_s(s, maxsize, localtime_s(timer))</pre>
- Recommended practice
+ asctime_s(s, maxsize, localtime_s(timer))
+</pre>
+<h6>Recommended practice</h6>
The strftime function allows more flexible formatting and supports locale-specific
behavior. If you do not require the exact form of the result string produced by the
ctime_s function, consider using the strftime function instead.
The ctime_s function returns zero if the time was successfully converted and stored
into the array pointed to by s. Otherwise, it returns a nonzero value.
-<a name="K.3.8.2.3" href="#K.3.8.2.3"><h5>K.3.8.2.3 The gmtime_s function</h5></a>
+<h5><a name="K.3.8.2.3" href="#K.3.8.2.3">K.3.8.2.3 The gmtime_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.26"><time.h></a>
struct tm *gmtime_s(const time_t * restrict timer,
- struct tm * restrict result);</pre>
+ struct tm * restrict result);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither timer nor result shall be a null pointer.
The gmtime_s function returns result, or a null pointer if the specified time cannot
be converted to UTC or there is a runtime-constraint violation.
-<a name="K.3.8.2.4" href="#K.3.8.2.4"><h5>K.3.8.2.4 The localtime_s function</h5></a>
+<h5><a name="K.3.8.2.4" href="#K.3.8.2.4">K.3.8.2.4 The localtime_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.26"><time.h></a>
struct tm *localtime_s(const time_t * restrict timer,
- struct tm * restrict result);</pre>
+ struct tm * restrict result);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither timer nor result shall be a null pointer.
The localtime_s function returns result, or a null pointer if the specified time
cannot be converted to local time or there is a runtime-constraint violation.
-<a name="K.3.9" href="#K.3.9"><h4>K.3.9 Extended multibyte and wide character utilities <wchar.h></h4></a>
+<h4><a name="K.3.9" href="#K.3.9">K.3.9 Extended multibyte and wide character utilities <wchar.h></a></h4>
<p><!--para 1 -->
The header <a href="#7.28"><wchar.h></a> defines two types.
<p><!--para 2 -->
The types are
<pre>
- errno_t</pre>
+ errno_t
+</pre>
which is type int; and
<pre>
- rsize_t</pre>
+ rsize_t
+</pre>
which is the type size_t.
<p><!--para 3 -->
Unless explicitly stated otherwise, if the execution of a function described in this
unspecified values.
<!--page 642 -->
-<a name="K.3.9.1" href="#K.3.9.1"><h5>K.3.9.1 Formatted wide character input/output functions</h5></a>
+<h5><a name="K.3.9.1" href="#K.3.9.1">K.3.9.1 Formatted wide character input/output functions</a></h5>
-<a name="K.3.9.1.1" href="#K.3.9.1.1"><h5>K.3.9.1.1 The fwprintf_s function</h5></a>
+<h5><a name="K.3.9.1.1" href="#K.3.9.1.1">K.3.9.1.1 The fwprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.28"><wchar.h></a>
int fwprintf_s(FILE * restrict stream,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither stream nor format shall be a null pointer. The %n specifier<sup><a href="#note416"><b>416)</b></a></sup> (modified or
example, if the entire format string was L"%%n".
</small>
-<a name="K.3.9.1.2" href="#K.3.9.1.2"><h5>K.3.9.1.2 The fwscanf_s function</h5></a>
+<h5><a name="K.3.9.1.2" href="#K.3.9.1.2">K.3.9.1.2 The fwscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
int fwscanf_s(FILE * restrict stream,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither stream nor format shall be a null pointer. Any argument indirected though in
compatible with rsize_t.
</small>
-<a name="K.3.9.1.3" href="#K.3.9.1.3"><h5>K.3.9.1.3 The snwprintf_s function</h5></a>
+<h5><a name="K.3.9.1.3" href="#K.3.9.1.3">K.3.9.1.3 The snwprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int snwprintf_s(wchar_t * restrict s,
rsize_t n,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. n shall neither equal zero nor be greater
example, if the entire format string was L"%%n".
</small>
-<a name="K.3.9.1.4" href="#K.3.9.1.4"><h5>K.3.9.1.4 The swprintf_s function</h5></a>
+<h5><a name="K.3.9.1.4" href="#K.3.9.1.4">K.3.9.1.4 The swprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.28"><wchar.h></a>
int swprintf_s(wchar_t * restrict s, rsize_t n,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. n shall neither equal zero nor be greater
example, if the entire format string was L"%%n".
</small>
-<a name="K.3.9.1.5" href="#K.3.9.1.5"><h5>K.3.9.1.5 The swscanf_s function</h5></a>
+<h5><a name="K.3.9.1.5" href="#K.3.9.1.5">K.3.9.1.5 The swscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.28"><wchar.h></a>
int swscanf_s(const wchar_t * restrict s,
- const wchar_t * restrict format, ...);</pre>
+ const wchar_t * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. Any argument indirected though in order
than provided for, or even zero, in the event of an early matching failure.
<!--page 646 -->
-<a name="K.3.9.1.6" href="#K.3.9.1.6"><h5>K.3.9.1.6 The vfwprintf_s function</h5></a>
+<h5><a name="K.3.9.1.6" href="#K.3.9.1.6">K.3.9.1.6 The vfwprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int vfwprintf_s(FILE * restrict stream,
const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither stream nor format shall be a null pointer. The %n specifier<sup><a href="#note420"><b>420)</b></a></sup> (modified or
example, if the entire format string was L"%%n".
</small>
-<a name="K.3.9.1.7" href="#K.3.9.1.7"><h5>K.3.9.1.7 The vfwscanf_s function</h5></a>
+<h5><a name="K.3.9.1.7" href="#K.3.9.1.7">K.3.9.1.7 The vfwscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.21"><stdio.h></a>
#include <a href="#7.28"><wchar.h></a>
int vfwscanf_s(FILE * restrict stream,
- const wchar_t * restrict format, va_list arg);</pre>
+ const wchar_t * restrict format, va_list arg);
+</pre>
value of arg after the return is indeterminate.
</small>
-<a name="K.3.9.1.8" href="#K.3.9.1.8"><h5>K.3.9.1.8 The vsnwprintf_s function</h5></a>
+<h5><a name="K.3.9.1.8" href="#K.3.9.1.8">K.3.9.1.8 The vsnwprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
int vsnwprintf_s(wchar_t * restrict s,
rsize_t n,
const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. n shall neither equal zero nor be greater
example, if the entire format string was L"%%n".
</small>
-<a name="K.3.9.1.9" href="#K.3.9.1.9"><h5>K.3.9.1.9 The vswprintf_s function</h5></a>
+<h5><a name="K.3.9.1.9" href="#K.3.9.1.9">K.3.9.1.9 The vswprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
int vswprintf_s(wchar_t * restrict s,
rsize_t n,
const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. n shall neither equal zero nor be greater
example, if the entire format string was L"%%n".
</small>
-<a name="K.3.9.1.10" href="#K.3.9.1.10"><h5>K.3.9.1.10 The vswscanf_s function</h5></a>
+<h5><a name="K.3.9.1.10" href="#K.3.9.1.10">K.3.9.1.10 The vswscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
int vswscanf_s(const wchar_t * restrict s,
const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s nor format shall be a null pointer. Any argument indirected though in order
value of arg after the return is indeterminate.
</small>
-<a name="K.3.9.1.11" href="#K.3.9.1.11"><h5>K.3.9.1.11 The vwprintf_s function</h5></a>
+<h5><a name="K.3.9.1.11" href="#K.3.9.1.11">K.3.9.1.11 The vwprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
#include <a href="#7.28"><wchar.h></a>
int vwprintf_s(const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
format shall not be a null pointer. The %n specifier<sup><a href="#note425"><b>425)</b></a></sup> (modified or not by flags, field
example, if the entire format string was L"%%n".
</small>
-<a name="K.3.9.1.12" href="#K.3.9.1.12"><h5>K.3.9.1.12 The vwscanf_s function</h5></a>
+<h5><a name="K.3.9.1.12" href="#K.3.9.1.12">K.3.9.1.12 The vwscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.16"><stdarg.h></a>
#include <a href="#7.28"><wchar.h></a>
int vwscanf_s(const wchar_t * restrict format,
- va_list arg);</pre>
+ va_list arg);
+</pre>
Runtime-constraints
<p><!--para 2 -->
format shall not be a null pointer. Any argument indirected though in order to store
value of arg after the return is indeterminate.
</small>
-<a name="K.3.9.1.13" href="#K.3.9.1.13"><h5>K.3.9.1.13 The wprintf_s function</h5></a>
+<h5><a name="K.3.9.1.13" href="#K.3.9.1.13">K.3.9.1.13 The wprintf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.28"><wchar.h></a>
- int wprintf_s(const wchar_t * restrict format, ...);</pre>
+ int wprintf_s(const wchar_t * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
format shall not be a null pointer. The %n specifier<sup><a href="#note427"><b>427)</b></a></sup> (modified or not by flags, field
example, if the entire format string was L"%%n".
</small>
-<a name="K.3.9.1.14" href="#K.3.9.1.14"><h5>K.3.9.1.14 The wscanf_s function</h5></a>
+<h5><a name="K.3.9.1.14" href="#K.3.9.1.14">K.3.9.1.14 The wscanf_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.28"><wchar.h></a>
- int wscanf_s(const wchar_t * restrict format, ...);</pre>
+ int wscanf_s(const wchar_t * restrict format, ...);
+</pre>
Runtime-constraints
<p><!--para 2 -->
format shall not be a null pointer. Any argument indirected though in order to store
provided for, or even zero, in the event of an early matching failure.
<!--page 653 -->
-<a name="K.3.9.2" href="#K.3.9.2"><h5>K.3.9.2 General wide string utilities</h5></a>
+<h5><a name="K.3.9.2" href="#K.3.9.2">K.3.9.2 General wide string utilities</a></h5>
-<a name="K.3.9.2.1" href="#K.3.9.2.1"><h5>K.3.9.2.1 Wide string copying functions</h5></a>
+<h5><a name="K.3.9.2.1" href="#K.3.9.2.1">K.3.9.2.1 Wide string copying functions</a></h5>
-<a name="K.3.9.2.1.1" href="#K.3.9.2.1.1"><h5>K.3.9.2.1.1 The wcscpy_s function</h5></a>
+<h5><a name="K.3.9.2.1.1" href="#K.3.9.2.1.1">K.3.9.2.1.1 The wcscpy_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
errno_t wcscpy_s(wchar_t * restrict s1,
rsize_t s1max,
- const wchar_t * restrict s2);</pre>
+ const wchar_t * restrict s2);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Neither s1 nor s2 shall be a null pointer. s1max shall not be greater than RSIZE_MAX.
fit within the array pointed to by s1 and that the result in s1 is null terminated.
</small>
-<a name="K.3.9.2.1.2" href="#K.3.9.2.1.2"><h5>K.3.9.2.1.2 The wcsncpy_s function</h5></a>
+<h5><a name="K.3.9.2.1.2" href="#K.3.9.2.1.2">K.3.9.2.1.2 The wcsncpy_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 7 -->
<pre>
errno_t wcsncpy_s(wchar_t * restrict s1,
rsize_t s1max,
const wchar_t * restrict s2,
- rsize_t n);</pre>
+ rsize_t n);
+</pre>
Runtime-constraints
<p><!--para 8 -->
Neither s1 nor s2 shall be a null pointer. Neither s1max nor n shall be greater than
int r1, r2, r3;
r1 = wcsncpy_s(dst1, 6, src1, 100);
r2 = wcsncpy_s(dst2, 5, src2, 7);
- r3 = wcsncpy_s(dst3, 5, src2, 4);</pre>
+ r3 = wcsncpy_s(dst3, 5, src2, 4);
+</pre>
The first call will assign to r1 the value zero and to dst1 the sequence of wide characters hello\0.
The second call will assign to r2 a nonzero value and to dst2 the sequence of wide characters \0.
The third call will assign to r3 the value zero and to dst3 the sequence of wide characters good\0.
fit within the array pointed to by s1 and that the result in s1 is null terminated.
</small>
-<a name="K.3.9.2.1.3" href="#K.3.9.2.1.3"><h5>K.3.9.2.1.3 The wmemcpy_s function</h5></a>
+<h5><a name="K.3.9.2.1.3" href="#K.3.9.2.1.3">K.3.9.2.1.3 The wmemcpy_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 14 -->
<pre>
errno_t wmemcpy_s(wchar_t * restrict s1,
rsize_t s1max,
const wchar_t * restrict s2,
- rsize_t n);</pre>
+ rsize_t n);
+</pre>
Runtime-constraints
<p><!--para 15 -->
Neither s1 nor s2 shall be a null pointer. Neither s1max nor n shall be greater than
Otherwise, a nonzero value is returned.
<!--page 656 -->
-<a name="K.3.9.2.1.4" href="#K.3.9.2.1.4"><h5>K.3.9.2.1.4 The wmemmove_s function</h5></a>
+<h5><a name="K.3.9.2.1.4" href="#K.3.9.2.1.4">K.3.9.2.1.4 The wmemmove_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 19 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.28"><wchar.h></a>
errno_t wmemmove_s(wchar_t *s1, rsize_t s1max,
- const wchar_t *s2, rsize_t n);</pre>
+ const wchar_t *s2, rsize_t n);
+</pre>
Runtime-constraints
<p><!--para 20 -->
Neither s1 nor s2 shall be a null pointer. Neither s1max nor n shall be greater than
The wmemmove_s function returns zero if there was no runtime-constraint violation.
Otherwise, a nonzero value is returned.
-<a name="K.3.9.2.2" href="#K.3.9.2.2"><h5>K.3.9.2.2 Wide string concatenation functions</h5></a>
+<h5><a name="K.3.9.2.2" href="#K.3.9.2.2">K.3.9.2.2 Wide string concatenation functions</a></h5>
-<a name="K.3.9.2.2.1" href="#K.3.9.2.2.1"><h5>K.3.9.2.2.1 The wcscat_s function</h5></a>
+<h5><a name="K.3.9.2.2.1" href="#K.3.9.2.2.1">K.3.9.2.2.1 The wcscat_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
errno_t wcscat_s(wchar_t * restrict s1,
rsize_t s1max,
- const wchar_t * restrict s2);</pre>
+ const wchar_t * restrict s2);
+</pre>
Runtime-constraints
<p><!--para 2 -->
Let m denote the value s1max - wcsnlen_s(s1, s1max) upon entry to
s2 were appended to the wide string pointed to by s1 and that the result in s1 is null terminated.
</small>
-<a name="K.3.9.2.2.2" href="#K.3.9.2.2.2"><h5>K.3.9.2.2.2 The wcsncat_s function</h5></a>
+<h5><a name="K.3.9.2.2.2" href="#K.3.9.2.2.2">K.3.9.2.2.2 The wcsncat_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 8 -->
<pre>
errno_t wcsncat_s(wchar_t * restrict s1,
rsize_t s1max,
const wchar_t * restrict s2,
- rsize_t n);</pre>
+ rsize_t n);
+</pre>
Runtime-constraints
<p><!--para 9 -->
Let m denote the value s1max - wcsnlen_s(s1, s1max) upon entry to
r1 = wcsncat_s(s1, 100, s5, 1000);
r2 = wcsncat_s(s2, 6, L"", 1);
r3 = wcsncat_s(s3, 6, L"X", 2);
- r4 = wcsncat_s(s4, 7, L"defghijklmn", 3);</pre>
+ r4 = wcsncat_s(s4, 7, L"defghijklmn", 3);
+</pre>
After the first call r1 will have the value zero and s1 will be the wide character sequence goodbye\0.
After the second call r2 will have the value zero and s2 will be the wide character sequence hello\0.
After the third call r3 will have a nonzero value and s3 will be the wide character sequence \0.
s2 were appended to the wide string pointed to by s1 and that the result in s1 is null terminated.
</small>
-<a name="K.3.9.2.3" href="#K.3.9.2.3"><h5>K.3.9.2.3 Wide string search functions</h5></a>
+<h5><a name="K.3.9.2.3" href="#K.3.9.2.3">K.3.9.2.3 Wide string search functions</a></h5>
-<a name="K.3.9.2.3.1" href="#K.3.9.2.3.1"><h5>K.3.9.2.3.1 The wcstok_s function</h5></a>
+<h5><a name="K.3.9.2.3.1" href="#K.3.9.2.3.1">K.3.9.2.3.1 The wcstok_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
wchar_t *wcstok_s(wchar_t * restrict s1,
rsize_t * restrict s1max,
const wchar_t * restrict s2,
- wchar_t ** restrict ptr);</pre>
+ wchar_t ** restrict ptr);
+</pre>
Runtime-constraints
<p><!--para 2 -->
None of s1max, s2, or ptr shall be a null pointer. If s1 is a null pointer, then *ptr
t = wcstok_s(NULL, &max1, ",", &ptr1); // t points to the token "??b"
t = wcstok_s(str2, &max2, " \t", &ptr2); // t is a null pointer
t = wcstok_s(NULL, &max1, "#,", &ptr1); // t points to the token "c"
- t = wcstok_s(NULL, &max1, "?", &ptr1); // t is a null pointer</pre>
+ t = wcstok_s(NULL, &max1, "?", &ptr1); // t is a null pointer
+</pre>
-<a name="K.3.9.2.4" href="#K.3.9.2.4"><h5>K.3.9.2.4 Miscellaneous functions</h5></a>
+<h5><a name="K.3.9.2.4" href="#K.3.9.2.4">K.3.9.2.4 Miscellaneous functions</a></h5>
-<a name="K.3.9.2.4.1" href="#K.3.9.2.4.1"><h5>K.3.9.2.4.1 The wcsnlen_s function</h5></a>
+<h5><a name="K.3.9.2.4.1" href="#K.3.9.2.4.1">K.3.9.2.4.1 The wcsnlen_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 1 -->
<pre>
#define __STDC_WANT_LIB_EXT1__ 1
#include <a href="#7.28"><wchar.h></a>
- size_t wcsnlen_s(const wchar_t *s, size_t maxsize);</pre>
+ size_t wcsnlen_s(const wchar_t *s, size_t maxsize);
+</pre>
<h6>Description</h6>
<p><!--para 2 -->
The wcsnlen_s function computes the length of the wide string pointed to by s.
wcsnlen_s useful in algorithms that gracefully handle such exceptional data.
</small>
-<a name="K.3.9.3" href="#K.3.9.3"><h5>K.3.9.3 Extended multibyte/wide character conversion utilities</h5></a>
+<h5><a name="K.3.9.3" href="#K.3.9.3">K.3.9.3 Extended multibyte/wide character conversion utilities</a></h5>
-<a name="K.3.9.3.1" href="#K.3.9.3.1"><h5>K.3.9.3.1 Restartable multibyte/wide character conversion functions</h5></a>
+<h5><a name="K.3.9.3.1" href="#K.3.9.3.1">K.3.9.3.1 Restartable multibyte/wide character conversion functions</a></h5>
<p><!--para 1 -->
Unlike wcrtomb, wcrtomb_s does not permit the ps parameter (the pointer to the
conversion state) to be a null pointer.
-<a name="K.3.9.3.1.1" href="#K.3.9.3.1.1"><h5>K.3.9.3.1.1 The wcrtomb_s function</h5></a>
+<h5><a name="K.3.9.3.1.1" href="#K.3.9.3.1.1">K.3.9.3.1.1 The wcrtomb_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 2 -->
<pre>
#include <a href="#7.28"><wchar.h></a>
errno_t wcrtomb_s(size_t * restrict retval,
char * restrict s, rsize_t smax,
- wchar_t wc, mbstate_t * restrict ps);</pre>
+ wchar_t wc, mbstate_t * restrict ps);
+</pre>
Runtime-constraints
<p><!--para 3 -->
Neither retval nor ps shall be a null pointer. If s is not a null pointer, then smax
<p><!--para 5 -->
If s is a null pointer, the wcrtomb_s function is equivalent to the call
<pre>
- wcrtomb_s(&retval, buf, sizeof buf, L'\0', ps)</pre>
+ wcrtomb_s(&retval, buf, sizeof buf, L'\0', ps)
+</pre>
where retval and buf are internal variables of the appropriate types, and the size of
buf is greater than MB_CUR_MAX.
<p><!--para 6 -->
The wcrtomb_s function returns zero if no runtime-constraint violation and no
encoding error occurred. Otherwise, a nonzero value is returned.
-<a name="K.3.9.3.2" href="#K.3.9.3.2"><h5>K.3.9.3.2 Restartable multibyte/wide string conversion functions</h5></a>
+<h5><a name="K.3.9.3.2" href="#K.3.9.3.2">K.3.9.3.2 Restartable multibyte/wide string conversion functions</a></h5>
<p><!--para 1 -->
Unlike mbsrtowcs and wcsrtombs, mbsrtowcs_s and wcsrtombs_s do not
permit the ps parameter (the pointer to the conversion state) to be a null pointer.
-<a name="K.3.9.3.2.1" href="#K.3.9.3.2.1"><h5>K.3.9.3.2.1 The mbsrtowcs_s function</h5></a>
+<h5><a name="K.3.9.3.2.1" href="#K.3.9.3.2.1">K.3.9.3.2.1 The mbsrtowcs_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 2 -->
<pre>
errno_t mbsrtowcs_s(size_t * restrict retval,
wchar_t * restrict dst, rsize_t dstmax,
const char ** restrict src, rsize_t len,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
Runtime-constraints
<p><!--para 3 -->
None of retval, src, *src, or ps shall be null pointers. If dst is not a null pointer,
terminating null character did not occur where required.
</small>
-<a name="K.3.9.3.2.2" href="#K.3.9.3.2.2"><h5>K.3.9.3.2.2 The wcsrtombs_s function</h5></a>
+<h5><a name="K.3.9.3.2.2" href="#K.3.9.3.2.2">K.3.9.3.2.2 The wcsrtombs_s function</a></h5>
<h6>Synopsis</h6>
<p><!--para 11 -->
<pre>
errno_t wcsrtombs_s(size_t * restrict retval,
char * restrict dst, rsize_t dstmax,
const wchar_t ** restrict src, rsize_t len,
- mbstate_t * restrict ps);</pre>
+ mbstate_t * restrict ps);
+</pre>
runtime-constraint violation.
</small>
-<a name="L" href="#L"><h2>Annex L</h2></a>
+<h2><a name="L" href="#L">Annex L</a></h2>
<pre>
(normative)
- Analyzability</pre>
+ Analyzability
+</pre>
-<a name="L.1" href="#L.1"><h3>L.1 Scope</h3></a>
+<h3><a name="L.1" href="#L.1">L.1 Scope</a></h3>
<p><!--para 1 -->
This annex specifies optional behavior that can aid in the analyzability of C programs.
<p><!--para 2 -->
specifications.
</small>
-<a name="L.2" href="#L.2"><h3>L.2 Definitions</h3></a>
+<h3><a name="L.2" href="#L.2">L.2 Definitions</a></h3>
-<a name="L.2.1" href="#L.2.1"><h4>L.2.1</h4></a>
+<h4><a name="L.2.1" href="#L.2.1">L.2.1</a></h4>
<p><!--para 1 -->
out-of-bounds store
an (attempted) access (<a href="#3.1">3.1</a>) that, at run time, for a given computational state, would
modify (or, for an object declared volatile, fetch) one or more bytes that lie outside
the bounds permitted by this Standard.
-<a name="L.2.2" href="#L.2.2"><h4>L.2.2</h4></a>
+<h4><a name="L.2.2" href="#L.2.2">L.2.2</a></h4>
<p><!--para 1 -->
bounded undefined behavior
undefined behavior (<a href="#3.4.3">3.4.3</a>) that does not perform an out-of-bounds store.
NOTE 2 Any values produced or stored might be indeterminate values.
-<a name="L.2.3" href="#L.2.3"><h4>L.2.3</h4></a>
+<h4><a name="L.2.3" href="#L.2.3">L.2.3</a></h4>
<p><!--para 1 -->
critical undefined behavior
undefined behavior that is not bounded undefined behavior.
<!--page 667 -->
-<a name="L.3" href="#L.3"><h3>L.3 Requirements</h3></a>
+<h3><a name="L.3" href="#L.3">L.3 Requirements</a></h3>
<p><!--para 1 -->
If the program performs a trap (<a href="#3.19.5">3.19.5</a>), the implementation is permitted to invoke a
runtime-constraint handler. Any such semantics are implementation-defined.
<!--page 668 -->
</ul>
-<a name="Bibliography" href="#Bibliography"><h2>Bibliography</h2></a>
+<h2><a name="Bibliography" href="#Bibliography">Bibliography</a></h2>
<ol>
<li> ''The C Reference Manual'' by Dennis M. Ritchie, a version of which was
published in The C Programming Language by Brian W. Kernighan and Dennis
<!--page 671 -->
</ol>
-<a name="Index" href="#Index"><h2>Index</h2></a>
+<h2><a name="Index" href="#Index">Index</a></h2>
<pre>
[^ x ^], <a href="#3.20">3.20</a> , (comma operator), <a href="#5.1.2.4">5.1.2.4</a>, <a href="#6.5.17">6.5.17</a>
, (comma punctuator), <a href="#6.5.2">6.5.2</a>, <a href="#6.7">6.7</a>, <a href="#6.7.2.1">6.7.2.1</a>, <a href="#6.7.2.2">6.7.2.2</a>,
projects / c-standard / blobdiff