C++ 多态性错误 : no matching function for call to

Question

我正在尝试将一个子对象传递给一个接受其父对象的函数，代码如下:

Rook bRookL();
board[0][0].setPieceObj(bRookL);

我得到以下错误:

    ChessBoard.cpp:16:35: error: no matching function for call to 'Space::setPieceObj(Rook (&)())'
     board[0][0].setPieceObj(bRookL);
                                   ^
In file included from ChessBoard.h:13:0,
                 from ChessBoard.cpp:5:
Space.h:62:10: note: candidate: void Space::setPieceObj(Piece&)
     void setPieceObj(Piece &);
          ^
Space.h:62:10: note:   no known conversion for argument 1 from 'Rook()' to 'Piece&'

这是我的代码:

棋盘.h:

#ifndef CHESSBOARD_H
#define CHESSBOARD_H

#include "Space.h"

using namespace std;

class ChessBoard {

private:
    Space board[8][8]; // board[0][0] is the upper-left corner of the board and
                       // board[7][7] is the lower-right corner of the board

public:
    ChessBoard();

};

#endif /* CHESSBOARD_H */

棋盘.cpp:

#include "ChessBoard.h"
#include "Space.h"
#include "Rook.h"

using namespace std;

ChessBoard::ChessBoard() {

    Rook bRookL();
    board[0][0].setPieceObj(&bRookL);

}

Rook.h:

#ifndef ROOK_H
#define ROOK_H

#include "Piece.h"

using namespace std;

class Rook : public Piece {

public:
    Rook() : Piece() {

    }

};

#endif /* ROOK_H */

片段.h:

#ifndef PIECE_H
#define PIECE_H

using namespace std;

class Piece {

public:
    Piece() {

    }

};

#endif /* PIECE_H */

空间.h:

#ifndef SPACE_H
#define SPACE_H

#include "Piece.h"
#include "Rook.h"

using namespace std;

class Space {

private:
    Piece *pieceObj;

public:
    void setPieceObj(Piece &);

};

#endif /* SPACE_H */

空间.cpp:

#include "Space.h"

using namespace std;

Space::Space() {



}

void Space::setPieceObj(Piece &p) {

    pieceObj = p;

}

请帮忙。谢谢。

Answer 1

根据对您的代码的检查，setPieceObj() 似乎应该采用指针参数:

void Space::setPieceObj(Piece *p) {

    pieceObj = p;

}

这是一个问题。现在，您需要传递一个指向 Piece 对象的指针。

Rook bRookL();
board[0][0].setPieceObj(&bRookL);

那是一个 most vexing parse ，它声明了一个返回 Rook 的函数，并将指向它的指针传递给 setPieceObj()。

没有足够的信息来确定您的明确意图。也许:

Rook bRook;
board[0][0].setPieceObj(&bRookL);