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

// union fields all share the same space in memory
union IntOrString {
    char* as_string;
    int as_int;
};

enum IntOrStringType {
    TYPE_STRING,
    TYPE_INT
};

void print_int_or_string(union IntOrString ios,
        enum IntOrStringType type) {
    if (type == TYPE_STRING) {
        printf("ios.as_string == %s\n", ios.as_string);
    } else if (type == TYPE_INT) {
        printf("ios.as_int == %d\n", ios.as_int);
    }
}

int main(int argc, char* argv[]) {
    union IntOrString ios = { .as_int = 5 };
    enum IntOrStringType type = TYPE_INT;

    print_int_or_string(ios, type);

    char stack_string[] = "Hello";
    ios.as_string = stack_string;
    type = TYPE_STRING;
    print_int_or_string(ios, type);

    return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */