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);