int distance(Coord first, Coord second); // podstawowa
int distance(Hex first, Hex second);
int distance(std::shared_ptr<hex> first, std::shared_ptr<hex> second);
Coord find_neighbour(Hex hex, Coord direction); // podstawowa
Coord find_neighbour(std::shared_ptr<Hex> hex, Coord direction);
std::shared_ptr<hex> find_neighbour_ptr(Hex hex, Coord direction); // podstawowa
std::shared_ptr<hex> find_neighbour_ptr(std::shared_ptr<Hex> hex, Coord direction);