#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
|| defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)
+FILE *fmemopen(void *, size_t, const char *);
+FILE *open_memstream(char **, size_t *);
FILE *fdopen(int, const char *);
FILE *popen(const char *, const char *);
int pclose(FILE *);