C++ C++；文件输出过程中的双精度值

我有下面的c代码++

ofstream myfile;
    myfile.open ("promise.txt");

    for( int rating=lowerLimit; rating<=upperLimit; rating++ )
    {
        promise = promisePVTable->getPromise(durationTable, rating, duration);

        myfile << "Promise  " << rating << " : " << promise << "\n";
        hurdle = rc_min(1, (promise - 1) / promise);

        hurdles.push_back(hurdle);
    }

流myfile的

；
myfile.open（“promise.txt”）；
对于（int评级=下限；评级GetPromise（持续时间表，评级，持续时间）；
myfile使用

#包括
//....
myfileofstream（或者实际上是从中派生ofstream的io_基）有一个“precision”函数，用于设置下一个浮点值的十进制精度

见：

所以你必须写：

myfile << "Promise  " << rating << " : ";
myfile.precision(16);
myfile << promise << "\n";

myfile
myfile << "Promise  " << rating << " : ";
myfile.precision(16);
myfile << promise << "\n";