1  typedef union {
       2    long l;
       3    struct { char b3, b2, b1, b0; } c;
       4  } T;
       5  
       6  f (T u)
       7  {
       8    ++u.c.b0;
       9    ++u.c.b3;
      10    return (u.c.b1 != 2 || u.c.b2 != 2);
      11  }
      12  
      13  main ()
      14  {
      15    T u;
      16    u.c.b1 = 2;
      17    u.c.b2 = 2;
      18    u.c.b0 = ~0;
      19    u.c.b3 = ~0;
      20    if (f (u))
      21      abort();
      22    exit (0);
      23  }