It doesn't. Sphinx still can't make any links, which btw also means that it's impossible to reference those methods within the Python documentation.

Also I want to point out that I find the information very hard to find as a human. The fact that integers are based on `numbers.Number` is -- at this point in time where 95% of all Python developers don't know about the `numbers` module or abstract base classes in general -- an implementation detail and as such should not affect the way `int` is documented.

I propose to have decent class references for int, str, ... similar to the reference for dict -- that is, document all attributes and methods in one place and make them referencable. For those who want to deep-dive into CPython internals, a note about those functionality actually being implemented in ABCs could be added.

(But I think that's out of scope for this ticket. I could open a new one if anyone agrees with me... :-)