Py2.3: Feedback on Sets

[Just]

In article <mailman.1061149114.2138.python-list at python.org>,
 cben at techunix.technion.ac.il (Beni Cherniavsky) wrote:

> What I do like is the auto-copying of mutable sets when used a set items; I
> wouldn't mind something like this to be extended into other Python types
> (primarily dicts).

Me too. I once proposed this on python-dev but there didn't seem to be 
much interest: 

http://mail.python.org/pipermail/python-dev/2003-February/033043.html

(I must admit, the second case I mention there has more or less gone 
away in the meantime, leaving only the C implementation for sets...)

Just