week5-app2.cpp

#include <iostream>


//  namespaces
//  Organize related data into classes or structs.
//  Use class if you have private data and some functionality
//  Use struct if you organize simple data.
//  Place a class related free functions in the same namespace with the class/struct.

//  Enumerations
//  Use class enum, plain enum converts members to integers and no namespace.
//  Problems: can assign different enums to each other, compare them(which is buggy)
enum Color { red, green, blue };                    // plain enum
enum Card { red_card, green_card, yellow_card };    // another plain enum
enum class Animal { dog, deer, cat, bird, human };  // enum class
enum class Mammal { kangaroo, deer, human };        // another enum class

int main()
{


    // examples of bad use of plain enums:
    Color color = Color::red;
    Card card = Card::green_card;

    int num = color;    // no problem

    if (color == Card::red_card) // no problem (bad)
        std::cout << "bad" << std::endl;

    if (card == Color::green)   // no problem (bad)
        std::cout << "bad" << std::endl;

    // examples of good use of enum classes (safe)
    Animal a = Animal::deer;
    Mammal m = Mammal::deer;

//    int num2 = a;   // error
//    if (m == a)         // error (good)
//        std::cout << "bad" << std::endl;

//    if (a == Mammal::deer) // error (good)
//        std::cout << "bad" << std::endl;
    return 0;
}