typeof

typeof.c

#include <stdio.h>
#include <stdlib.h>

#define test(x) ({ \
    typeof(x) _x = (x); \
    _x += 1; \
    _x; \
})

int main(int argc, char* argv[])
{
    float f = 0.5F;
    float f2 = test(f);
    printf("%f\n", f2);
    return EXIT_SUCCESS;
}