c++ - 无法访问派生类中的基类方法

Question

我有一个基类如下:

template<typename aGamePieceBase> class GamePiece : public aGamePieceBase
{
public:
    // Each GamePiece contains a definition of the base class from which it was derived
    typedef aGamePieceBase gamePieceBase

    // Returns this piece's sprite
    virtual sf::Sprite* getSprite()
    {
        return m_pSprite;
    }
protected:
    sf::Sprite* m_pSprite;
}

还有一个派生的类:

class Horse : public GameBoard::GamePiece< GameBoard::GamePieceBase >
{
public:
    virtual sf::Sprite* getSprite() override
    {
        // Do stuff
    }
};

但是我在 Horse::getSprite 减速时遇到了这个错误用 override 声明的成员函数不会覆盖基类成员

为什么 getSprite 在 Horse 中不可用？

GamePieceBase 如下:

class GamePieceBase : public GameEventHandler
{
public:
    // Called when the GamePiece has been added to the GameBoard 
    template<typename aTileBase> virtual void onPieceCreate( Tile<aTileBase> *startingLocation ){}
    // Called when the GamePiece has been removed from the GameBoard
    virtual void onPieceRemove(){}
    // Called when the user has selected this GamePiece
    virtual void onPieceSelect(){}
    // Called when the user has de-selected this GamePiece
    virtual void onPieceDeselect(){}
    // Called when this GamePiece has moved on the board
    template<typename originTileBase, typename destinationTileBase> virtual void onPieceMove( Tile<originTileBase>* originTileBase, Tile<destinationTileBase>* pDestinationTile ){}
};

编辑:输出日志表明有一个内部编译器 error 但没有提供很多细节。我现在正在调查这个

Answer 1

这对我有用:

class GamePieceBase
{
public:
    // Called when the GamePiece has been added to the GameBoard 
};


template<typename aGamePieceBase> class GamePiece : public aGamePieceBase
{
public:
    // Each GamePiece contains a definition of the base class from which it was derived
//  typedef aGamePieceBase gamePieceBase

    // Returns this piece's sprite
    virtual int getSprite()
    {
        return 0;
    }
protected:

};


class Horse : public GamePiece< GamePieceBase >
{
public:
    virtual int getSprite() override
    {
        return 0;
    }
};

但是，最好这样写:

int getSprite() override

显式编写 virtual、override 或 final 是 self 记录的，使编译器能够捕获类型和/或名称之间的不匹配基类和派生类。但是，编写这三者中的一个以上既是多余的，也是潜在的错误来源。 C++ CoreGuidelines C.128