Clarify that a TypeVarTuple default always has to be unpacked #1971
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The spec says that: 1. The default of a TypeVarTuple can be another TypeVarTuple 2. TypeVarTuples are always unpacked. Together, these suggest that the default of a TypeVarTuple has to be an *unpacked* TypeVarTuple, and indeed [pyright](https://pyright-play.net/?pyrightVersion=1.1.386&code=GYJw9gtgBALgngBwJYDsDmUkQWEMoAqiApgGoCGIBArggDbEA0UAqiguQMYDWAUAQGcAjFAC8hEhSq0GACgDkgofICU-AQCYxEhGUo16xBYI3zmAE2LBy1OjFFK1ggMzaiuqQbmKBzs1EtrW3s2Dh4AbSUAXRUgA) and [mypy](https://mypy-play.net/?mypy=latest&python=3.12&gist=b6b01c533c7930e1e520765b773d1fe1) both agree. This PR makes that clear and adds a corresponding conformance test. I don't think this needs a discussion + Typing Council approval, since it's just a clarification of an existing rule, but happy to go through the full process if anyone disagrees.
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I agree this is just a clarification. The new wording is clearer. |
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The spec says that:
Together, these suggest that the default of a TypeVarTuple has to be an unpacked TypeVarTuple, and indeed pyright and mypy both agree. This PR makes that clear and adds a corresponding conformance test.
I don't think this needs a discussion + Typing Council approval, since it's just a clarification of an existing rule, but happy to go through the full process if anyone disagrees.