为什么这个编译错误？ - 没有匹配函数来调用'std :: basic_ofstream <char> :: open(std :: string&)'

Question

这适用于Visual Studio,它适用于一台计算机上的GCC 4.9.2.

但在另一台计算机上,我认为它是相同的GCC 4.9.2编译器,但它给了我这个错误.

我错过了什么吗？这是怎么回事？

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main()
{
    string filename;
    filename = "teststring";
    ofstream fout;
    fout.open(filename);
    fout << "Hello world!" << endl;
    fout.close();
    return 0;
}

.

||=== Build: Debug in fileiotest (compiler: TDM32 GNU GCC Compiler 4.9.2 dw2) ===|
F:\Users\XXX\cpp\fileiotest\main.cpp||In function 'int main()':|
F:\Users\XXX\cpp\fileiotest\main.cpp|12|error: no matching function for call to 'std::basic_ofstream<char>::open(std::string&)'|
F:\Users\XXX\cpp\fileiotest\main.cpp|12|note: candidate is:|
F:\TDM-GCC-32\lib\gcc\mingw32\4.9.2-dw2\include\c++\fstream|716|note: void std::basic_ofstream<_CharT, _Traits>::open(const char*, std::ios_base::openmode) [with _CharT = char; _Traits = std::char_traits<char>; std::ios_base::openmode = std::_Ios_Openmode]|
F:\TDM-GCC-32\lib\gcc\mingw32\4.9.2-dw2\include\c++\fstream|716|note:   no known conversion for argument 1 from 'std::string {aka std::basic_string<char>}' to 'const char*'|
||=== Build failed: 1 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|

Answer 1

这个重载是C++ 11中的新增功能,这意味着您需要传递-std=c++11构建命令.

在C++ 03中,我们曾经写过:

fout.open(filename.c_str());