Is there a 'catch' with FastFormat?

Question

I just read about the FastFormat C++ i/o formatting library, and it seems too good to be true: Faster even than printf, typesafe, and with what I consider a pleasing interface:<

Answer 1

Is there a 'catch' with FastFormat?

Last time I checked, there was one annoying catch:

You can only use either the narrow string version or the wide string version of this library. (The functions for wchar_t and char are the same -- which type is used is a compile time switch.)

With iostreams, stdio or Boost.Format you can use both.