Enums and Enum Classes

Just like in C you can use normal enums and they work the same way.

Enum classes

Enum classes or so called scoped enumerations make enumerations both strongly typed and strongly scoped. Class enums don’t allow implicit conversions to int, and also don’t allow comparisons between different enumerations.


#include <iostream>
using namespace std;
 
int main()
{
    enum class Color {
        Red,
        Green,
        Blue
    };
    enum class State {
        Good,
        Bad
    };
 
    // An enum value can be used as variable identifier
    int Green = 10;
 
    // Instantiating the Enum Class
    Color x = Color::Green;
 
    // Comparison now is completely type-safe
    if (x == Color::Red)
        cout << "It's Red\n";
    else
        cout << "It's not Red\n";
 
    State p = State::Good;
 
    if (p == State::Bad)
        cout << "Something went wrong\n";
    else
        cout << "All is good\n";
 
    // won't work because no implicit conversion to int
    // if(x == p)
    // cout<<"red is equal to good";
    // cout<< x;
    cout << int(x);
 
    return 0;
}