I doubt there's an mmap(2) on Windows. I'd rather call an existing file copy function than make and test my own.
But if you are already using features from boost::filesystem you can use copy_file from that. I just think that, if not already required for something else, it's a tad overkill.
Thanks. I thought it would be in there somewhere.
We already use boost::filesystem in a dozen places. It's not a new added dependency. It gives us a lot of portable stuff that we would otherwise have to have a #ifdef for each OS and test everywhere.