Issue 5184: Add -3 warning for extension types that implement tp_compare but not tp_richcompare (original) (raw)

See

http://mail.python.org/pipermail/python-dev/2009-February/085809.html

where Nick Coghlan writes:

"I'm wondering if Mark should add the exception he recently removed back in as a Deprecation Warning when tp_compare is defined, but tp_richcompare is not. Such a warning should also be present when running with -3 in 2.7 (assuming it isn't already there)."

A technical difficulty with adding this warning is that various built-in types implement tp_compare but not tp_richcompare. For example: int, long, slice, buffer, instancemethod, cell and bool all do this.