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

typedef union {  // shares the same space in memory for *ONE* of the fields
    int   as_int;     // 4 bytes (on our platform)
    char* as_string;  // 8 bytes ("  "   "       )
    float as_float;   // 4 bytes ("  "   "       )
    //            WHOLE: 8 bytes (max of 4, 8 ,4)
} Element;

typedef enum { ELEMENT_INT, ELEMENT_STRING, ELEMENT_FLOAT } ElementType;
// const int ELEMENT_INT = 1, ELEMENT_STRING = 2, ELEMENT_FLOAT = 3;

void print_element(Element element, ElementType element_type) {
    if(element_type == ELEMENT_INT) {
        printf("element.as_int == %d\n", element.as_int);
    }
    else if(element_type == ELEMENT_FLOAT) {
        printf("element.as_float == %f\n", element.as_float);
    }
    else if(element_type == ELEMENT_STRING) {
        printf("element.as_string == %s\n", element.as_string);
    }
    else {
        assert(false);  // unexpected element_type
    }
}
int main(int argc, char* argv[]) {
    Element     element      = { .as_int = 5 };
    ElementType element_type = ELEMENT_INT;
    print_element(element, element_type);

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