Save/Persist FIX::SessionSettings to file

In QuickFIX/j it is possible to save (an updated) SessionSettings to a file using toStream:

public static void writeSettings(SessionSettings settings, File settingsFile) throws IOException {
    FileOutputStream settingsOut = new FileOutputStream(settingsFile);
    try {
        settings.toStream(settingsOut);
    } finally {
        settingsOut.close();
    }
}

However FIX::SessionSettings (c++) does not have this function defined in their class reference.

Is there an easy way to achieve this using the C++ library, or should I port this method myself?