Question

class Game
{
public:
    static void Start();

private:
    static bool IsExiting();
    static void GameLoop();

    static void ShowSplashScreen();
    static void ShowMenu();

    enum GameState { Uninitialized, ShowingSplash, Paused,
                    ShowingMenu, Playing, Exiting };

    Game::GameState Game::_gameState = Game::Uninitialized;
    static sf::RenderWindow _mainWindow;
};
Game::GameState Game::_gameState;
RenderWindow Game::_mainWindow;

Error is now in function that runs first

void processEvents(){// error: first defined here ???
    Event event;
    while(App.pollEvent(event)){
        if(event.type == Event::Closed)
                App.close();
    }
}

And there are also other error such as multiple definition of `Game::_gameState’ in function it gives the same errors in other functions that are declared in Game class

void Game::Start(void) { // multiple definition of `Game::_gameState'
    if (_gameState != Uninitialized)
        return;

    _mainWindow.create(VideoMode(1200, 900, 32), "Game",
            Style::Close);
    _gameState = Game::ShowingSplash;

    while (!IsExiting()) {
        GameLoop();
    }

    _mainWindow.close();
}

I fixed the errors but one more showed up

while (!IsExiting()) {  //undefined reference to Game::IsExiting
    GameLoop();
}

_mainWindow.close();

}

I don’t know it is static bool function other functions works fine but this one is bool and gives me errors

Answer 1

Because the enum GameState is contained within class Game you need to scope the variable accordingly:

Game::GameState Game::_gameState;