Function overloading in C

overloading.c

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

enum discriminateFunc {
    NO_RETURN,
    INT_RETURN,
    INT_RETURN_TAKE_INT,
};

union funcUnion {
    void (*no_return)();
    int (*int_return)();
    int (*int_return_take_int)(int);
};

static void __overloaded(enum discriminateFunc d, union funcUnion f) {
    switch (d) {
        case NO_RETURN:
            f.no_return();
            break;
        case INT_RETURN: {
            int ret = f.int_return();
            printf("Called func and it returned %d\n", ret);
            break;
        }
        case INT_RETURN_TAKE_INT: {
            int ret = f.int_return_take_int(42);
            printf("Called func with 42 and it returned %d\n", ret);
            break;
        }
    }
}

void A() {
    printf("Called func with no args and no return\n");
}

int B() {
    printf("Called func with no args and returns 32\n");
    return 32;
}

int C(int arg) {
    printf("Called func with int arg (got %d) and returns 14\n", arg);
    return 14;
}

#define overloaded(d, x) __overloaded(d, (union funcUnion)x)

int main() {
    overloaded(NO_RETURN, A);
    overloaded(INT_RETURN, B);
    overloaded(INT_RETURN_TAKE_INT, C);

    return EXIT_SUCCESS;
}