Open
Description
Issue type: Bug
Python version: 3.8
mypy version: 0.760
mypy flags: whatever the defaults are on https://mypy-play.net/
I discovered this issue when playing around with a monad-y Either
thing (and here's it working in Typescript)
Here is (I think) a minimal repro:
from typing import Callable, TypeVar, Generic
def foo() -> int:
return 1
T = TypeVar('T')
bar: Callable[[], T] = foo
main.py:7: error: Incompatible types in assignment (expression has type "Callable[[], int]", variable has type "Callable[[], T]")
I would expect that in the type declaration of bar
, T
would unify with int
, but clearly it does not.