Need to get the rects from a Region

[David Sharp]

I need to send Expose messages to my windows. I would like to only
Expose an invalidated Region that I can keep track of. However, Expose
events only send rectangles, and I cannot get a list of rectangles
from a Region.

Why does XLib provide no means of getting a list of rectangles from a
Region? One possible way around this is to define _XRegion and Box for
myself and hack the Region pointer (see
http://freedesktop.org/cgi-bin/viewcvs.cgi/X11/include/X11/region.h?root=xlibs&view=auto
).I don't believe this a good solution, as it is
implementation-specific, but I wonder if it is safe. How likely is it
that the _XRegion struct will change?

Or perhaps ther is another solution that I missed?

Thanks,
David Sharp