Sorry for the slightly off-topic question.  I am starting to use swig
to wrap some C++ library for ruby for the first time.
In the process of doing so, I realize I will need to pass proc objects
from ruby and turn them into function pointers in C, so as to provide a
callback mechanism.
I understand this can potentially be done with typemaps, but I am not
sure exactly how.  I only need to have a single callback per class, so
I was thinking of storing the ruby callback within the class itself and
then have a common C wrap function that would map the C callback to the
appropiate ruby callbacks (ie. proc object) based on what was stored in
the class.  I was also unsure if SWIG already provides some auxiliary
functions for doing something similar.
Does anyone have any pointers?
I'm already familiar with how ruby-fltk handles this, for example, and
I want to basically emulate something akin within the SWIG
meta-language.  I'm looking at FXRuby but the code is a tad too complex
for a SWIG newbie.