> Why do you think it makes a difference?
Because adding one more dependency on unneeded libraries add the pain. Also it limit us on very restricted API of that wrapper. Windows native API is stable. So it's OK to rely on it's documented imlementation.

Suppose, we receive file-descriptor from _open_osfhandle.... For example it is a socket. It still unusable for stdin. Many standard functions does not work with such handle. The list of available functions : http://msdn.microsoft.com/en-us/library/kdfaxaay.aspx . As we see it is very narrow and function names are not POSIX-compatible (_chsize vs ftruncate). Documentation is very poor. For example, _close() is documented only here: http://msdn.microsoft.com/en-US/library/40bbyw78(v=VS.80).aspx .