Wrapper/Proxy Generic Type

I've been putting some work into typeshed pull requests and I've noticed some places where I could really have used a Proxy Generic class - meaning I can inherit from Proxy[T] and that means that whatever attributes T has, Proxy[T] also has. We don't want to directly mark this as inheritance since then the distinction of a proxy is lost.

The examples I ran into are ProxyType and CallableProxyType in weakref or SynchronizedBase in multiprocessing,csharedtypes.
A big one would be unittest.Mock (See https://github.com/python/mypy/issues/1188).
I'm sure other cases exist,

Advantages:

• Representing a proxy type easily
• Allowing type checkers to enforce typing

Disadvantages:

• Functions that get T won't accept Proxy[T] as an argument. Although the current state is probably something similar.

I'd really like to hear some opinions on the idea.

Comece lendo a proposta e sua discussão, incluindo os exemplos envolvendo weakref, multiprocessing.sharedctypes e unittest.Mock, além da issue vinculada do mypy. Um resultado útil exigiria um acordo sobre se Proxy[T] pertence ao design de typing e uma especificação clara de seu comportamento.