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.

Beginnen Sie mit dem Lesen des Vorschlags und der dazugehörigen Diskussion, einschließlich der Beispiele zu weakref, multiprocessing.sharedctypes und unittest.Mock sowie des verlinkten mypy-Issues. Ein nützliches Ergebnis würde eine Einigung darüber erfordern, ob Proxy[T] zum typing-Design gehört, sowie eine klare Spezifikation seines Verhaltens.