__typeof__ example in GCC

maxmin.c

#include <stdio.h>

#define MIN(X,Y) ((X) < (Y) ? (X) : (Y))

#define min(a, b) \
  ({  __typeof__ (a) _a = (a); \
		__typeof__ (b) _b = (b); \
		_a > _b ? _b : _a; })

#define max(a, b) \
	({  __typeof__ (a) _a = (a); \
		__typeof__ (b) _b = (b); \
		_a > _b ? _a : _b; })

int main(int argc, char** argv)
{
	int a = 5;
	int b = 3;

	printf("Smaller value (not safe): %d\n", MIN(a, b));
	printf("a: %d, b: %d\n", a, b);

	printf("Smaller after ++ (safe): %d\n", min(a++, ++b));
	printf("a: %d, b: %d\n", a, b);

	printf("Smaller after ++ (not safe): %d\n", MIN(a++, b++));
	printf("a: %d, b: %d\n", a, b);

	int c = 7;
	int d = 8;
	printf("Larger value: %d\n", max(c, d));

	return 0;
}