It's unclear how to set __weaklistoffset__ Python 3.11 and below

[encukou]

PyType_Slot can’t set tp_weaklistoffset, the 3.12 documentation suggests usingPy_TPFLAGS_MANAGED_WEAKREF: Type Objects. But this tp flag is only available in 3.12. So how would one use it in 3.12 and use multiphase init with tp_weaklistoffset for older Pythons?

It's unclear in the current docs. IMO the 3.11 version was clear, but that hint is now effectively soft-deprecated.

Linked PRs

• gh-110803: Reorganize docs for what PyType_Slot doesn't cover #110813
• [3.12] gh-110803: Reorganize docs for what PyType_Slot doesn't cover (GH-110813) #110823