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

union IntOrString { 
    int as_number;   // 4 bytes
    char* as_string; // 8 bytes
};
enum ValueType {
    VALUE_INT,
    VALUE_STRING
};

struct IntAndString {  // a struct with these would be 12+ bytes
    int as_number;   // 4 bytes
    char* as_string; // 8 bytes
};

#define log_size(n) printf("sizeof(%s) == %ld\n", #n, sizeof(n))
#define log_int(n) printf("%s == %d\n", #n, n)
#define log_str(n) printf("%s == \"%s\"\n", #n, n)

void print_int_or_string(union IntOrString value, enum ValueType type) {
    switch(type) {
        case VALUE_INT:
            printf("Value is %d\n", value.as_number);
            break;
        case VALUE_STRING:
            printf("Value is %s\n", value.as_string);
            break;
    }
}

int main(int argc, char* argv[]) {
    log_size(struct IntAndString);
    log_size(union IntOrString);

    union IntOrString value = { .as_number = 7 };
    log_int(value.as_number);
    // seg fault trying to print the string
    // log_str(value.as_string);
    union IntOrString value2 = { .as_string = "Hello World" };
    log_str(value2.as_string);
    log_int(value2.as_number);

    value2.as_number = 81;
    log_int(value2.as_number);
    //log_str(value2.as_string);
    value2.as_string = "ECE 264";

    print_int_or_string(value, VALUE_INT);
    print_int_or_string(value2, VALUE_STRING);
    
    return EXIT_SUCCESS;
}
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