Portability issue in file IO

A std::ofstream is an output stream. By definition, it cannot input data. So giving it fstream::in as a flag is wrong.

If you want a file stream you can input and output to, use std::fstream.

Admittedly, this may not be what's causing your problem. But it is wrong.

The most common reason stuff doesn't get written to a file is because you forgot to close the stream when you were done: myfile.close(); somewhere before the program exits. This flushes the buffer and makes sure everything is actually written to the file, and not sitting in any caches along the way.d