我如何在这里追加而不是覆盖? (这段代码如何打开文件?)

How do I append instead of overwrite here? (and how does this code open a file?)

我正在阅读 OpenFoam (v7) (C++) 教程并遇到了 IO 的代码:

    // Create a custom directory and write an output file

    // Create the output path directory
    fileName outputDir = mesh.time().path()/"postProcessing";
    // Createe the directory
    mkDir(outputDir);
    // File pointer to direct the output to
        autoPtr<OFstream> outputFilePtr;
    // Open the file in the newly created directory
    outputFilePtr.reset(new OFstream(outputDir/"customOutputFile.dat");
    // Write stuff
    outputFilePtr() << "# This is a header" << endl;
    outputFilePtr() << "0 1 2 3 4 5" << endl;

谁能帮忙解释一下这个文件是怎么打开的(我不明白outputFilePtr.reset(new OFstream(outputDir/"customOutputFile.dat");) 以及如何追加而不是覆盖?添加 std::ios::app 在这里似乎不起作用。

openfoam-v7 的构造函数是:

        OFstream
        (
            const fileName& pathname,
            streamFormat format=ASCII,
            versionNumber version=currentVersion,
            compressionType compression=UNCOMPRESSED,
            const bool append = false
        );

可以找到here

141         outputFilePtr.reset( new OFstream(outputDir/"customOutputFile.dat",
142                                 ASCII,
143                                 currentVersion,
144                                 UNCOMPRESSED,
145                                  true) );

失败错误:“ASCII”未在此范围内声明, 错误:“currentVersion”未在此范围内声明,并且 错误:未在此范围内声明“UNCOMPRESSED”。

非常感谢您的帮助。

OFstream构造函数:

OFstream(
    const fileName& pathname,
    IOstreamOption  streamOpt = IOstreamOption(),
    const bool      append = false 
)

所以:

outputFilePtr.reset( new OFstream(outputDir/"customOutputFile.dat", 
                                  IOstreamOption(),
                                  true) );

编辑:对于旧版 OpenFOAM 的错误,很可能是命名空间问题:

outputFilePtr.reset( new OFstream(outputDir/"customOutputFile.dat",
                                  Foam::IOstream::ASCII
                                  Foam::IOstream::currentVersion,
                                  Foam::IOstream::UNCOMPRESSED,
                                  true) );