enum class member

gistfile1.cpp

//Pure virtual abstract base class for game state management
    class AppState : public virtual SFMLEventHandler
    {
    public:
        AppState(sf::RenderWindow &disp)
        : display(disp)
        {
        }
        virtual ~AppState() = default;

        virtual void onRender() = 0;
        
        enum States {CURRENTSTATE = 0, STARTMENUSTATE, CHESSPLUSPLUSSTATE};
        
        virtual States stateChange() = 0;

    protected:
        sf::RenderWindow &display;
        States destState;
    };


error: expected identifier before ‘,’ token
       enum States {CURRENTSTATE = 0, STARTMENUSTATE, CHESSPLUSPLUSSTATE};