ctypes/__init__.pyi uses TypeVar within ClassVar #6333

I just implemented a check in pyright to report an error if a TypeVar is used within a ClassVar declaration. PEP 526 specifically says:

Note that a ClassVar parameter cannot include any type variables, regardless of the level of nesting: ClassVar[T] and ClassVar[List[Set[T]]] are both invalid if T is a type variable.

A similar feature request was recently filed in the mypy issue tracker.

Here's the issue in the pyright issue tracker: microsoft/pyright#2567.

This check is highlighting a problem in the pointer class defined within the ctypes/__init__.pyi stub.

class pointer(Generic[_CT], _PointerLike, _CData):
    _type_: ClassVar[Type[_CT]]

I don't know enough about ctypes to suggest a proper fix.