python / python/mypy

(🐞) overloaded instance not accepted as instance

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bug
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Python
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Description

from typing import overload

class A:
    def __init__(self, _): ...
    def __call__(self, a: int = 1): ...

@overload
def f(): ...

@overload
def f(a: int): ...

@A
def f(): ...

a: A = f  # E: Incompatible types in assignment (expression has type overloaded function, variable has type "A")  [assignment]

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First steps

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Research direction

Start with the supplied reproducer, tracing how mypy checks assignment of the overloaded function decorated with the callable instance A. Confirm the behavior against the reported diagnostic and related overload handling. Done means the overloaded instance is accepted as an A while incompatible assignments still produce the appropriate error.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
devtools
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

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