/*[XSI]*/ #if 202405L <= _POSIX_C_SOURCE #define _XOPEN_SOURCE 800 #elif 200809L <= _POSIX_C_SOURCE #define _XOPEN_SOURCE 700 #endif #include #ifdef getpwent #undef getpwent #endif struct passwd *(*foo)(void) = getpwent; int main(void) { return 0; }