A std::map of sf::vector2f

[schmitty]

Is it possible to create a map with the key being an sf::vector2f? I think i need to overload the comparison operator to get it to work. If it is possible, could someone kindly explain how to accomplish this?

Thanks!

[Nexus]

Don't overload operator<, since it doesn't mathematically make sense for vectors.

You can write a functor. Here I just add the components, you can also check for x coordinates first and then y (lexicographically), for this std::pair already provides what you want.

struct VectorComparator
{
    bool operator() (sf::Vector2f lhs, sf::Vector2f rhs) const
    {
        return lhs.x + lhs.y < rhs.x + rhs.y;
    }
}

The associative STL containers take a further template parameter that specify the ordering criterion.

std::map<sf::Vector2f, Value, VectorComparator> map;