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

// BAD WAY #2:  use integer constants to indicate type.
//              But... when we see an int, we usually assume a number of things, not a
//              special value.

union Value {
    int   as_int;
    char* as_string;
};
// A union object can contain only one of the fields; they share the same space.

int TYPE_INT = 0;
int TYPE_STRING = 1;

void print_element(union Value the_value, int type_of_value) {
    if(type_of_value == TYPE_INT) {
        printf("the_value is %d\n", the_value.as_int);
    }
    else {
        printf("the_value is %s\n", the_value.as_string);
    }
}

int main(int argc, char* argv[]) {
    union Value the_value = { .as_int = 5 };
    the_value.as_int = 7;
    print_element(the_value, TYPE_INT);

    the_value.as_string = "apple";
    print_element(the_value, TYPE_STRING);
    
    return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */

© Copyright 2023 Alexander J. Quinn         This content is protected and may not be shared, uploaded, or distributed.