/*[XSI]*/ #if 202405L <= _POSIX_C_SOURCE #define _XOPEN_SOURCE 800 #elif 200809L <= _POSIX_C_SOURCE #define _XOPEN_SOURCE 700 #endif #include void foo(struct utmpx* bar) { char *qux = bar->ut_id; (void) qux; } int main(void) { return 0; }