[ZODB-Dev] BTree sets and unhashable objects

[Roché Compaan]

I was using OOSet for set operations on sequences of objects in the ZODB
and was getting horrably incorrect results. After I reread the Btrees Wiki
I noticed that the objects should be hashable, which they weren't of
course. Maybe the set classes can be so nice as to not accept unhashable
objects in the first place and stop stupidly forging ahead in its tracks
;-)

-- 
Roché Compaan
Upfront Systems                 http://www.upfrontsystems.co.za