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