c++ - ostream 和 ofstream 运算符重载歧义问题

Question

我正在尝试重载 ofstream 和 ostream 运算符，但我遇到了问题。我正在使用 ofstream 保存活动游戏并使用 ostream 在终端上打印。

这是我得到的错误：

hex_game.cpp: In member function ‘void Hex::saveGame(const string&)’:
hex_game.cpp:375:18: warning: ISO C++ says that these are ambiguous, even though the worst conversion for the first is better than the worst conversion for the second:
  375 |  myfile << (*this);
      |                  ^
hex_game.cpp:193:11: note: candidate 1: ‘std::ofstream& operator<<(std::ofstream&, const Hex&)’
  193 | ofstream& operator <<(ofstream& fileOutput, const Hex& obj){
      |           ^~~~~~~~
hex_game.cpp:207:10: note: candidate 2: ‘std::ostream& operator<<(std::ostream&, Hex&)’
  207 | ostream& operator <<(ostream& outputStream, Hex& obj){

第 375 行：

 void Hex::saveGame(const string& file_path){

 ofstream myfile;
 myfile.open(file_path);

    myfile << (*this);
    cout << "Game has been saved!" << endl;
    myfile.close();
}

ostream 的定义 [用于在终端上打印电路板]

ostream& operator <<(ostream& outputStream, Hex& obj){
    if(obj.getGameplayType() == 1){
        outputStream << "Player1's Score: " << obj.getScoreP1() << " points" << "  |  Player2's Score: " << obj.getScoreP2() << " points";
    }
    else{
        outputStream << "Player's Score: " << obj.getScoreP1() << " points";
    }

    outputStream << "\n\n ";
    for(int i=0; i<obj.getBoardSize(); i++){
        outputStream << " " <<obj.hexCells[0][i].column;
    }
    outputStream << endl;
    for(int i=0; i<obj.getBoardSize(); i++){
        outputStream << i + 1;
        if(i+1 < 10) outputStream << " "; 
        if(i >= 1){
            for(int j=0; j<i; j++) outputStream << " ";
        }
        for(int k=0; k<obj.getBoardSize(); k++){
            outputStream << " " << obj.hexCells[i][k].point;
        }
        outputStream << endl;
    }
return outputStream;
}

ofstream 的定义 [用于将活动游戏保存到 .TXT 文件中]

ofstream& operator <<(ofstream& fileOutput, const Hex& obj){
    fileOutput << obj.getGameplayType() << endl;
    fileOutput << obj.getBoardSize() << endl;
    fileOutput << obj.getTurn() << endl;

    for(int i=0; i<obj.getBoardSize(); i++){
        for(int k=0; k<obj.getBoardSize(); k++){
            fileOutput << obj.hexCells[i][k].point;  
        }
        fileOutput << endl;
    }
return fileOutput;
}

我在网上搜索了我的答案，我得到了一些帮助，但我还没有修复这个错误。我通过在 Hex 构造函数之前添加显式关键字来解决其他歧义问题，但这个不是固定的。有人能帮我吗？

（我必须为 ostream 和 ofstream 重载 <<。这是我的作业，我的同学这样做了，但他们没有收到任何警告。如果有另一种方法（正确），我想学习并在我的代码中实现。）

标签： c++c++11operator-overloadingoverloading