1  struct s
       2  {
       3    int i[18];
       4    char f;
       5    char b[2];
       6  };
       7  
       8  struct s s1;
       9  
      10  int
      11  main()
      12  {
      13    struct s s2;
      14    s2.b[0] = 100;
      15    __builtin_memcpy(&s2, &s1, ((unsigned int) &((struct s *)0)->b));
      16    if (s2.b[0] != 100)
      17      abort();
      18    exit(0);
      19  }