How to refer to different enum values which share a duplicate name? - objective-c

Question

I have 2 enums.
typedef enum {
BLUE = 1,
RED = 2
} FavoriteColor;
typedef enum {
ORANGE = 1,
YELLOW = 2,
RED = 3
} Color;
In my code how can I refer to a specific RED from FavoriteColor enum, but not Color enum?

Answer 1

You can't. And the compiler should warn you about that.
enum constants live in the global namespace. The second definition is a redefinition that should produce an error.

Answer 2

It is not possible to have scoped enumerations. The general way around this is to use prefixes which appear in most libraries like UIKit. You should define your enumerations like this:
typedef enum {
FavoriteColorBlue = 1,
FavoriteColorRed= 2
} FavoriteColor;
typedef enum {
ColorOrange = 1,
ColorYellow = 2,
ColorRed= 3
} Color;
The only other way would be to use a class with static access to constants as described here.

Answer 3

use enum class instead just enum. Then you can use the same names for different enums;
// ConsoleApplication3.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
using namespace std;
enum class window {large,small};
enum class box {large,small};
int main()
{
window mywindow;
box mybox;
mywindow = window::small;
mybox = box::small;
if (mywindow == window::small)
cout << "mywindow is small" << endl;
if (mybox == box::small)
cout << "mybox is small" << endl;
mybox = box::large;
if (mybox != box::small)
cout << "mybox is not small" << endl;
cout << endl;
}