这里编译错误：

synthesized method ‘File& File::operator=(const File&)’ first required here

我有这段代码：

void FileManager::InitManager()
{
    int numberOfFile = Settings::GetSettings()->NumberOfFile() + 1;
 
    for( unsigned int i = 1; i < numberOfFile; i++ )
    {
        std::string path = "data/data" ;
        path += i;
        path += ".ndb";
 
        File tempFile( path );
 
        _files.push_back( tempFile ); // line that cause the error
 
        /*if( PRINT_LOAD )
        {
            std::cout << "Adding file " << path << std::endl;
        }*/
    }
}

_files如果在此标头中定义：

#pragma once
 
//C++ Header
#include <vector>
 
//C Header
 
//local header
#include "file.h"
 
class FileManager
{
public:
    static FileManager* GetManager();
    ~FileManager();
 
    void LoadAllTitle();
 
private:
    FileManager();
    static FileManager* _fileManager;
 
    std::vector<File> _files;
};

File是我创建的对象,它只不过是一个处理文件IO的简单接口.我以前已经完成了用户定义对象的向量,但这是我第一次遇到这个错误.

这是File对象的代码：
File.h

#pragma once
 
//C++ Header
#include <fstream>
#include <vector>
#include <string>
 
//C Header
 
//local header
 
class File
{
public:
    File();
    File( std::string path );
    ~File();
 
    std::string ReadTitle();
 
    void ReadContent();
    std::vector<std::string> GetContent();
 
private:
    std::ifstream _input;
    std::ofstream _output;
 
    char _IO;
    std::string _path;
    std::vector<std::string> _content;
};

File.cpp

#include "file.h"
 
File::File()
    : _path( "data/default.ndb" )
{
}
 
File::File( std::string path )
    : _path( path )
{
}
 
File::~File()
{
}
 
void File::ReadContent()
{
}
 
std::string File::ReadTitle()
{
    _input.open( _path.c_str() );
    std::string title = "";
 
    while( !_input.eof() )
    {
        std::string buffer;
        getline( _input,buffer );
 
        if( buffer.substr( 0,5 ) == "title" )
        {
            title = buffer.substr( 6 ); // 5 + 1 = 6... since we want to skip the '=' in the ndb
        }
    }
 
    _input.close();
    return( title );
}
 
std::vector<std::string> File::GetContent()
{
    return( _content );
}

我在linux下用gcc工作.

任何有关解决方案的提示或提示都表示赞赏.

对不起,很长的帖子.

谢谢