Accessing to enum values by '::' in C++

Question

I have class like following:

class Car  
{  
public:  
    Car();  
    // Some functions and members and enums  
    enum Color
    {
              


        

Answer 1

Name the enum inside the nested class (as example one):

class Car
{
public:
    struct Color
    {
        enum Type
        {
            Red,
            Blue,
            Black
        };
    };

    Color::Type getColor();
    void setColor(Color::Type);
};

Answer 2

In current C++ (i.e. C++11 and beyond), you can already access enum values like that:

enum Color { Red };
Color c = Color::Red;
Color d = Red;

You can go further and enforce the use of this notation:

enum class Color { Red };
Color c = Color::Red;
// Color d = Red;   <--  error now

And on a sidenote, you now define the underlying type, which was previously only possible with hacky code (FORCEDWORD or so anyone?):

enum class Color : char { Red };

Answer 3

When I want to do something like this I tend to use a namespace and a typedef outside of th namespace (though usually I'm doing this globally rather than inside a class). Something like this:

namespace colors 
{
    enum Color 
    {
        Red,
        Blue
        ...
    }
}
typedef colors::Color Color;

This way you use the namespace to get at the actual colors, but the Color type itself is still globally accessible:

Color myFav = colors::Red;