Enumeration Classes

enum_class_1.cpp

#include <iostream>
#include <string>
using namespace std;

enum class TrafficLight { green, yellow, red };

TrafficLight& operator++(TrafficLight& light) {
    switch (light) {
        case TrafficLight::green:
            return light = TrafficLight::yellow;
        case TrafficLight::yellow:
            return light = TrafficLight::red;
        case TrafficLight::red:
            return light = TrafficLight::green;
    }
}

ostream& operator<<(ostream& out, const TrafficLight& light)
{
    static const vector<string> names {"green", "yellow", "red"};

    return out << names[static_cast<string::size_type>(light)];
}