[Python-Dev] making weakref.ref objects subclassable

[Tim Peters]

[Tim]
>> For reasons given above, I believe gc performance will be virtually
>> unchanged for almost all programs.

[Fred Drake]
> That was my conclusion as well.  Empirical evidence with the Zope 3 test
> suite suggests that's right.  If anyone has an application that would be
> meaningfully affected by this change, I'd be rather surprised, and would
> appreciate hearing about it.

For the reasons given before, that won't happen.  The analysis I gave was
based on a complete understanding of every gory detail of how Python's gc
works -- there's simply nothing risky about this change wrt gc performance.
Empirical validation is unnecessary <wink>.

If people want to surprise us, better they spend time writing nasty new
tests of weakref subclassing!