Constrained TypeVars with Any default

Bug Report

In python/typeshed#13683 I'm trying to change a type var to the following:

_I = TypeVar("_I", int, bytes, float, bool, default=Any)  # possibly memoryview types

Unfortunately, mypy complains: error: TypeVar default must be one of the constraint types [misc]. While this is of course generally sound advice, a default of Any should always be permissible, as this allows memoryview to stand for any possible memoryview type. Without it, users are forced to write memoryview[Any] in every instance, which is unreasonable.

Your Environment

• Mypy version used: 1.18.2

mypy 1.18.2 を使って、報告された TypeVar 宣言と「TypeVar default must be one of the constraint types」エラーを再現してください。まず、制約付き TypeVar のデフォルト値に対する検証箇所を特定します。このケースで Any のデフォルト値が受け入れられ、他のデフォルト値のチェックを弱めない状態になれば完了です。