6 int mbtowc(wchar_t *restrict wc, const char *restrict src, size_t n)
9 const unsigned char *s = (const void *)src;
16 if (*s < 0x80) return !!(*wc = *s);
17 if (MB_CUR_MAX==1) return (*wc = CODEUNIT(*s)), 1;
18 if (*s-SA > SB-SA) goto ilseq;
21 /* Avoid excessive checks against n: If shifting the state n-1
22 * times does not clear the high bit, then the value of n is
23 * insufficient to read a character */
24 if (n<4 && ((c<<(6*n-6)) & (1U<<31))) goto ilseq;
26 if (OOB(c,*s)) goto ilseq;
33 if (*s-0x80u >= 0x40) goto ilseq;
40 if (*s-0x80u >= 0x40) goto ilseq;
41 *wc = c<<6 | *s++-0x80;