/* dummy variables to play with */
int a = 0, b = 0, c = 0;


/* first flag */
#define  MY_FIRST_FLAG              (1 << 0)

/* second flag */
#define  MY_SECOND_FLAG             (1 << 1)

/*
 * some param that could have three variants
 */
#define  __MY_TRISTATE_OFFSET       2
#define  __MY_TRISTATE_MASK         (0x03 << __MY_TRISTATE_OFFSET)
#define  _MY_TRISTATE_ONE           (0 << __MY_TRISTATE_OFFSET)
#define  _MY_TRISTATE_TWO           (1 << __MY_TRISTATE_OFFSET)
#define  _MY_TRISTATE_THREE         (2 << __MY_TRISTATE_OFFSET)

/* third flag */
#define  MY_THIRD_FLAG              (1 << 4)


void my_func(int opts)
{
   if (opts & MY_FIRST_FLAG){
      a++;
   }

   switch (opts & __MY_TRISTATE_MASK){
      case _MY_TRISTATE_ONE:
         b++;
         break;
      case _MY_TRISTATE_TWO:
         c++;
         break;
      case _MY_TRISTATE_THREE:
         c += 2;
         break;
      default:
         c--;
         break;
   }

   a += 2;
}



enum my_tristate_e {
   MY_TRISTATE_ONE,
   MY_TRISTATE_TWO,
   MY_TRISTATE_THREE,
};

struct my_func_opts_s {
   unsigned             my_first_flag  : 1;
   unsigned             my_second_flag : 1;
   enum my_tristate_e   my_tristate    : 2;
   unsigned             my_third_flag  : 1;
};


void my_func2(struct my_func_opts_s opts)
{
   if (opts.my_first_flag){
      a++;
   }

   switch (opts.my_tristate){
      case MY_TRISTATE_ONE:
         b++;
         break;
      case MY_TRISTATE_TWO:
         c++;
         break;
      case MY_TRISTATE_THREE:
         c += 2;
         break;
      default:
         c--;
         break;
   }

   a += 2;
}


int main(int argc, char** argv)
{
   my_func(_MY_TRISTATE_TWO | MY_FIRST_FLAG);
   my_func2((struct my_func_opts_s){
         .my_first_flag = 1,
         .my_tristate   = MY_TRISTATE_TWO,
         });

   return 0;
}