[issue31108] add __contains__ for list_iterator (and others) for better performance

[Serhiy Storchaka]

Changes by Serhiy Storchaka <storchaka+cpython at gmail.com>:


----------
resolution:  -> rejected
stage: patch review -> resolved
status: open -> closed

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue31108>
_______________________________________