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tuple[Concatenate[int, ...]] should not be accepted #20452
Description
Bug Report
Passing Parameters to a tuple should not be allowed. Splitting off of python/typing#2140.
To Reproduce
from typing import Concatenate
def c(t: tuple[Concatenate[int, ...]]) -> None:
reveal_type(t) # N: Revealed type is "tuple[[builtins.int, *Any, **Any]]"Expected Behavior
Argument gets flagged.
Actual Behavior
Argument isn't flagged.
Your Environment
Reproduced in mypy-play.
- Mypy version used: 1.19.1
- Mypy command-line flags: none
- Mypy configuration options from
mypy.ini(and other config files): N/A - Python version used: 3.12
Activity
Vaishnavi-KN16 commentedon Dec 25, 2025
Concatenate represents callable parameter lists per PEP 612 and should be rejected when used as a normal type argument (e.g., inside tuple[...] or list[...]).
Assert that Parameters are not passed to tuples (#20477)
FMorgan-111 commentedon Jul 4, 2026
JelleZijlstra commentedon Jul 5, 2026
Sounds like you need a better AI