/**
 * Program showing the reasonable use of a union
 * The union is used within a struct that holds 
 * what the union is storing and the union.
 * **/

#include <stdio.h>

// These defines cover what could be in the union.  
// could be done with an enum instead
#define INTEGER 1
#define DOUBLE 2
#define CHAR 3

// a type to hold what info the union contains
typedef unsigned char unionType;

/** 
 * The union, holds an int, double OR char
 * **/
typedef union
{
    int a;
    double b;
    char c;
} uuu;

/**
 * A struct to wrap the union and hold its contents
 * as well as what it contents are
 * **/
typedef struct {
    unionType whichOne; 
    uuu foo;
} sss;

/** 
 * Put an int into the union.
 * This should be "public" in the struct .c file
 * @param ii an int
 * **/
sss putint(int ii) {
    sss ret;
    ret.whichOne = INTEGER;
    ret.foo.a = ii;
    return ret;
}

/** 
 * Put a double into the union.
 * This should be "public" in the struct .c file
 * @param dd a double
 * **/
sss putdouble(double dd) {
    sss ret;
    ret.whichOne = DOUBLE;
    ret.foo.b = dd;
    return ret;
}


/**
 * Print the contents of the structure
 * @param str the structure to be printed
 * **/
void printStruct(sss str) {
    switch (str.whichOne) {
        case INTEGER:
            printf("INT %d\n", str.foo.a);
            break;
        case DOUBLE:
            printf("DOU %.2f\n", str.foo.b);
            break;
        }
}

int main(int argc, char const *argv[])
{
    sss aaa[10];
    for (int i = 0; i < 10; i++)
        if (i%2==0)
            aaa[i] = putdouble(i * 5.0);
        else
            aaa[i] = putint(i * 5);
    for (int i = 0; i < 1000; i++) {
        printf("%d ", i);
        printStruct(aaa[i]);
    }
        return 0;
}