Functor Iobuf_debug.Make

module Make: 
functor (* : sig
end) -> sig .. end
Parameters:
* : ()

include ??
We use module type of struct include Iobuf end rather than module type of Iobuf so that the debugging functions work on normal Iobufs.
val check_invariant : bool Pervasives.ref
val show_messages : bool Pervasives.ref