Typechecking macro in c

typechecking_macros.c

#include <stdio.h>

#define min_t(type, x, y) ({                        \
            type __min1 = (x);                      \
            type __min2 = (y);                      \
            __min1 < __min2 ? __min1: __min2; })

/* generate warning if the types are unmatched: "comparison of distinct pointer types lacks a cast" */
#define min(x, y) ({                                \
            typeof(x) _min1 = (x);                  \
            typeof(y) _min2 = (y);                  \
            (void) (&_min1 == &_min2);              \ 
            _min1 < _min2 ? _min1 : _min2; })


int main(int argc, char const *argv[])
{
  int a = 12;
  unsigned b = 14;
  printf("min_t: %d\n", min_t(int, a, b));
  printf("min: %d\n", min(a, b));
  return 0;
}