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

// ENUM

#define log_int(x) printf("%s == %d\n", #x, (x))
#define log_float(x) printf("%s == %.060f\n", #x, (x))
#define log_double(x) printf("%s == %.060lf\n", #x, (x))
#define log_str(x) printf("%s == \"%s\"\n", #x, (x))

typedef union {
    int    as_int;
    float  as_float;
} Number;

typedef enum { NUMBER_INT = 1, NUMBER_FLOAT } NumberType;
// Use ' = 1' so that if you write if(number_type) { … }
// it will be easier to catch the mistake.

void print_number(Number n, NumberType number_type) {
    //if (number_type == 1) {  // *** do not use magic numbers ***
    if (number_type == NUMBER_INT) {
        printf("n:  %d\n", n.as_int);
    }
    else {
        printf("n:  %.060f\n", n.as_float);
    }
}

int main(int argc, char* argv[]) {
    Number n1 = { .as_int   = 8     };
    Number n2 = { .as_float = 0.125 };
    print_number(n1, NUMBER_INT);
    print_number(n2, NUMBER_FLOAT);

    return EXIT_SUCCESS;
}
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