1struct s
2{
3  int a;
4  int b;
5  struct s *dummy;
6};
7
8f (struct s *sp)
9{
10  return sp && sp->a == -1 && sp->b == -1;
11}
12
13main ()
14{
15  struct s x;
16  x.a = x.b = -1;
17  if (f (&x) == 0)
18    abort ();
19  exit (0);
20}
21