Dear all,

in CIL <http://cil.sf.net>, the module Pretty provides a Format-like
interface with a few extensions compared to usual format strings.
Implementation-wise, it uses string_of_format and re-implements most of
the logic of the pre-4.02 Format module, with Obj.magic all over the
place.

I wondered if anyone has done something similar in their own project
(extending Format in one way or another), and if the new GADT-based
approach could provide a cleaner solution?

One thing I quite like with the current code, despite its uglyness, is
its concision. I am right in assuming that switching to GADTs would
require a lot more boilerplate?