1 typedef union 2 { 3 int __lock; 4 } pthread_mutex_t; 5 6 extern void abort (void); 7 main()8 int main() 9 { 10 struct { int c; pthread_mutex_t m; } r = { .m = 0 }; 11 if (r.c != 0) 12 abort (); 13 return 0; 14 } 15