1  typedef enum { POSITION_ASIS, POSITION_UNSPECIFIED } unit_position;
       2  
       3  typedef enum { STATUS_UNKNOWN, STATUS_UNSPECIFIED } unit_status;
       4  
       5  typedef struct
       6  {
       7    unit_position position;
       8    unit_status status;
       9  } unit_flags;
      10  
      11  extern void abort (void);
      12  
      13  void
      14  new_unit (unit_flags * flags)
      15  {
      16    if (flags->status == STATUS_UNSPECIFIED)
      17      flags->status = STATUS_UNKNOWN;
      18  
      19    if (flags->position == POSITION_UNSPECIFIED)
      20      flags->position = POSITION_ASIS;
      21  
      22    switch (flags->status)
      23      {
      24      case STATUS_UNKNOWN:
      25        break;
      26  
      27      default:
      28        abort ();
      29      }
      30  }
      31  
      32  int main()
      33  {
      34    unit_flags f;
      35    f.status = STATUS_UNSPECIFIED;
      36    new_unit (&f);
      37    return 0;
      38  }