class GUIGroup :public GUIElement
{
public:
    GUIGroup(std::string name)
        :
        GUIElement(name, {0,0,0,0},GROUP,0)
    {}
    bool IsHover() const override
    {
        bool overlap = false;
        for (auto& i : group)
        {
            if (i->IsHover())
            {
                overlap = true;
                break;
            }
        }
        return Hover = overlap; // (Hover)expression must be modifiable value
    }
private:
    std::vector<std::shared_ptr<GUIElement>> group;
};

class GUIElement
{
public:
    virtual  bool IsHover() const { return Hover; }
protected:
    bool Hover = false;
};