from typing import assert_never
def f(value: float | tuple[float, float]) -> None:
match value:
case (_, _):
pass
case float():
pass
case _ as unreachable:
assert_never(unreachable)ERROR Argument `tuple[float, float]` is not assignable to parameter `arg` with type `Never` in function `typing.assert_never` [bad-argument-type]
--> repro.py:11:26
|
11 | assert_never(unreachable)
| ^^^^^^^^^^^
Describe the Bug
unreachableshould be narrowed toNeverafter the sequence and class patterns have matched all arms of the union.Sandbox Link
https://pyrefly.org/sandbox/?project=N4IgZglgNgpgziAXKOBDAdgEwEYHsAeAdAA4CeS4ATrgLYAEALqcROgOZ0Q3G6UN2o4cGHwD66GADcRAHXRy5mGGDpgAFJNRQArjESqouVPwA%2BjbcVgBtMIeMAaA0YYBdAJR0AtAD46AOVwJRDk6ULoaYwBjAAs6TR09ELDkyMEYOjVRR1E3YPRkgrDiQTgkwtThJ2M1XLLCopK6lLS6UQE4Om10ShhUGNRsWDz6gpKRBnEpETUunr7ogdg3ORB7EDIe21JCBlooCgBiOgAFUk2oUjo0LDx8OkjAyDZtSmMIQMI5I4BlGHTohgMYhwRAAelBG2UF0IvDYoJg6FBmFwkTgoIe6CeLzegVBql4Ak00EW6QxWNeDHe%2BVwxEpgTgn3QZAY0UCnmklDgVLoAF46DIQABmQgARgATAK5FYRNROS45F0uDw%2BDBMJ5MBAepFKdJeXQAOQQNjoXgwfVyE0MTw9ACO2k1qs8AGsYKRPH1IvAOnz9QB3VCUdDm9AgAC%2Baz6OpgADFoDAKNccAQSORQ0A
(Only applicable for extension issues) IDE Information
No response