1  struct a
       2  {
       3    unsigned int bitfield : 3;
       4  };
       5  
       6  int main()
       7  {
       8    struct a a;
       9  
      10    a.bitfield = 131;
      11    foo (a.bitfield);
      12    exit (0);
      13  }
      14  
      15  foo(unsigned int z)
      16  {
      17    if (z != 3)
      18      abort ();
      19  }