C++写入txt

C++写文件，会从str.txt中读取内容写入到str2.txt中

#include <stdlib.h>
#include <fstream>
#include <string>
#include <iostream>

int main(int argc, char* argv[])
{
    std::ifstream fIn("str.txt");
    std::ofstream fOut("str2.txt");
    if (!fIn)
    {
        std::cout << "Open input file faild." << std::endl;
    }
    if (!fOut)
    {
        std::cout << "Open output file faild." << std::endl;
    }
    std::string str;
    while (std::getline(fIn, str))
    {
        std::cout << str << std::endl;
        fOut << str << std::endl;
    }
    fIn.close();
    fOut.close();
    system("pause");
    return 0;
}