Easily gets the type of a variable.

type-checker.c

#include <stdio.h>
#include <limits.h>

#define typeof(x) \
	(((x == 0) ? (x = 0.00000000001) : (x)) / INT_MAX == 0) \
	? ("0cs0i0000"[sizeof(x)]) \
	: ("0000f000d"[sizeof(x)])

int main() {
    char c;
    int i;
    float f;
    double d;
    short int s;
    
    printf("char: %c\n", typeof(c));
    printf("int: %c\n", typeof(i));
    printf("float: %c\n", typeof(f));
    printf("double: %c\n", typeof(d));
    printf("short int: %c\n", typeof(s));
	
    return 0;
}