[gtkmm] How to use the clipboard?

["Benjamin A. Cooper" <bacooper bacwater net>]

I have been digging through the documentation for almost half a day now, 
and I still can't quite figure out how to fully utilise the clipboard, I 
must be missing something.

My main questions are: how do I copy arbitrary text to the clipboard? 
And, more importantly, How do I monitor the clipboard in order to set 
the sensitivity of the Paste menu item?