extern "C" {
#endif
+#include <features.h>
+
int isalnum(int);
int isalpha(int);
int isblank(int);
#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
- || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
+ || defined(_BSD_SOURCE)
#define __NEED_locale_t
#include <bits/alltypes.h>