Is using a enum class inside of a class class un-necessary

debugcn Published at Dev

mreff555

I should start by saying I'm fairly new to OOP. I am trying to write a portable class which will probably be used in multiple programs. The class requires multiple enumerated lists to store information which are only relevant to the class so I was planning on nesting the enum inside the class. My questions are

Is there any reason to use an enum class inside a class, or should I just use enum? Just curious. I posted sample code for reference below.
Is there any reason why it would be a really bad idea to make enums in a class public?

#include <iostream>

enum class Color {
    red     = 0,
    green   = 1,
    blue    = 2
};

class CodeLibray {
public:
    enum Color2 {
        red     = 0,
        green   = 1,
        blue    = 2
    };
    enum class Color3 {
        red     = 0,
        green   = 1,
        blue    = 2
    };
    Color color;
    Color2 color2; 
    Color3 color3;
}; 

int main(){
    CodeLibray c;
    c.color = Color::red;
    c.color2 = CodeLibray::Color2::blue;
    c.color3 = CodeLibray::Color3::blue;
}

πάντα ῥεῖ

Is there any reason to use an enum class inside a class, or should I just use enum? Just curious. I posted sample code for reference below.

It's pretty obvious that the enum values defined inside CodeLibray would become ambigous if you omit the enum class there.

Also, If I want enums to be accessible for assigning public member values but I do not want values in the enum to be changed is this possible?

I don't fully understand what you mean. Just a shot in the dark, something like the following?

enum Color2 {
    red     = ::red,
           // ^^ Refer to the enum declaration in the global namespace
    green   = ::green,
    blue    = ::blue
};
enum class Color3 {
    red     = ::red,
    green   = ::green,
    blue    = ::blue
};

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