Creating a composite type from two enum classes, ready for STL map

Question

I would like to create a composite type out of two enum classes.

enum class Color {RED, GREEN, BLUE};
enum class Shape {SQUARE, CIRCLE, TRIANGLE};

         


        

Answer 1

Consider using simply std::tuple as the "composite enum." This will come with comparison operators already defined for you, using a dictionary ordering. For example, valid code:

bool b = std::make_tuple(Color::RED, Shape::CIRCLE)
       < std::make_tuple(Color::GREEN, Shape::SQUARE);