Backward compatibility

[Alfredo Kojima <akojima gmail com>]

Hi

I have written a couple of tools using gtkmm-2.2, but wanted to update
to gtkmm-2.4  Problem is that some distributions ship 2.4,
some ship 2.2 and I suppose that soon, some will start shipping 2.6
(or 2.8). Furthermore, it seemed that gtkmm-2.4 was incompatible with
2.2, mainly because of the switch to libsigc++-2.0  Since I don't want
to maintain several versions of the same tool, are there any
compile-time compatibility macros or something? Would that be possible
at all? Was the compatibility broken only in the 2.2 to 2.4 switch or
do all other major version updates require code changes to allow the
app to work?

Thanks,
Alfredo