Archive save may fail silently

[chestnutprog]

When the archive file is locked by another program, the archive save will silently fail. Should we consider checking the return value of file operations, or replacing them with std::filesystem?

https://github.com/troldal/Zippy/blob/a838de8522f9051df0d1b202473bb6befe648702/library/Zippy/ZipArchive.hpp#L491