Attempting to reference a deleted function (VS2013)

问题

I'm trying to write a game of checkers in SDL. When I compile my code, I get this error:

std::basic_ifstream>::basic_ifstream(conststd::basic_ifstream> &)' : attempting to reference a deleted function

From what I can find on the web, this means that the compile has helpfully deleted my constructor for some reason, and now it can't find it again. (Bad organization if you ask me) Why could this be?

Board.h:

#include <fstream>
class Board
{
public:
    SDL_Surface * boardSurface;
    int boardArray[8][8];
private:
    std::ifstream boardFile;
    SDL_Surface * blackPiece;
    SDL_Surface * whitePiece;
    SDL_Surface * darkSquare;
    SDL_Surface * lightSquare;

public:
    Board(char filename[], SDL_PixelFormat * format);
private:
    void loadFile(char filename[]);
    void makeSurface();
    void debugPrint();
    void debugBlit();
};

Board.cpp:

#include <SDL.h>
#include <fstream>
#include <iostream>
#include <stdlib.h>
#include "board.h"
#include "loaders.h"

Board::Board(char filename[], SDL_PixelFormat * format)
{
    //inits images
    loaders imageLoader;
    blackPiece = imageLoader.load_image("images/blackPiece.png", format);
    whitePiece = imageLoader.load_image("images/whitePiece.png", format);
    darkSquare = imageLoader.load_image("images/darkSquare.png", format);
    lightSquare = imageLoader.load_image("images/lightSquare.png", format);
    boardSurface = SDL_CreateRGBSurface(0, 780, 480, 8, 0, 0, 0, 0);
    loadFile(filename);
    debugPrint();
    debugBlit();
}
void Board::loadFile(char filename[])
{
    boardFile.open(filename);
    char currentLine[9] = {};
    for (int line = 0; line <= 7; line++)
    {
        boardFile.getline(currentLine, 9);
        for (int square = 0; square <= 7; square++)
        {
            int currentSquare = (int)currentLine[square] - '0'; 
            boardArray[line][square] = currentSquare;
        }
    }
}

void Board::makeSurface()
{

}

void Board::debugPrint()
{
    for (int line = 0; line <= 7; line++)
    {
        for (int square = 0; square <= 7; square++)
        {
            std::cout << boardArray[line][square];
        }
        std::cout << std::endl;
    }
}

void Board::debugBlit()
{
    for (int y = 0; y <= 4; y++)
    {
        if (SDL_BlitSurface(blackPiece, NULL, boardSurface, NULL) != 0)
        {
            std::cout << SDL_GetError();
        }
    }
}

回答1:

The error happens because you have an std::ifstream data member, and you are probably trying to copy a Board somewhere, or have some code that requires the copy constructor to be accessible.

std::ifstream boardFile;

The Board compiler-provided copy constructor tries to copy the stream, but the stream is not copyable. So you have to either provide your own copy constructor to do something clever, or remove code that requires the Board copy constructor.

来源：https://stackoverflow.com/questions/21664164/attempting-to-reference-a-deleted-function-vs2013

标签

c++

sdl-2