Gtkmm 2.4 on top of Gtk 2.2?

[Toralf Lund <toralf procaptura com>]

Does anyone here have any thoughts on whether or not it would be 
realistic to create a variant of the Gtkmm 2.4 API that would run on top 
of Gtk 2.2? I mean without support for the widgets that are new in Gtk 
2.4 (and 2.6, 2.8 etc...), of course.

The thing is, we have some code written for Gtkmm 2.4 (or the "2.4" API, 
anyway), and intended for newer Fedora Core and Red Hat Enterprise 
Linux, that someone now has decided must work on some old Red Hat Linux 
9 installation - which have Gtk 2.2. So I'm wondering if it would be 
easier to back-port Gtkmm than to re-write the application code, or try 
to upgrade all of Gtk. We might still have to rewrite some code so that 
it avoids using new widgets, of course, but that's quite all right.

Any thoughts?

(I'll probably try to build and see how far I get, but thought I might 
ask here before starting...)

- Toralf