1  struct a { unsigned int bitfield : 1; };
       2  
       3  unsigned int x;
       4  
       5  main()
       6  {
       7    struct a a = {0};
       8    x = 0xbeef;
       9    a.bitfield |= x;
      10    if (a.bitfield != 1)
      11      abort ();
      12    exit (0);
      13  }