[issue23290] Faster set copying

[Serhiy Storchaka]

Serhiy Storchaka added the comment:

Except one error (the declaration after the code), the patch LGTM. It is shame to me that I left so much non-optimized code in specialized loops.

The result of my microbenchmarks is the speed up 51%, 153%, 23% and 96% respectively.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue23290>
_______________________________________