Hmm. This looks like it deals with UNC paths. I think the parent is asking about what are sometimes called "Win32 file namespace paths" - or at least defined as such by the MSDN article that is canonical https://msdn.microsoft.com/en-us/library/windows/desktop/aa3...

These are sometimes erroneously called UNC paths because, well, they _look_ like UNC paths. But UNC paths are used to refer to a path on another host. (In fact, you can specify UNC paths using the Win32 file namespace using the `\\?\UNC\server\resource` mechanism.)

It looks like win_unc will help with UNC, but it looks from a quick glance that it will not help with `\\?\` paths.