Hashable and List are considered overlapping

[shoyer]

I think this is a bug:

from typing import Hashable, List, overload

@overload
def f(x: Hashable) -> str: ...

@overload
def f(x: List) -> str: ...

def f(x):
    return repr(x)

mypy (0.720) reports:

typing_test.py:7: error: Overloaded function signature 2 will never be matched: signature 1's parameter type(s) are the same or broader

I would expect this to work without complaints. Python lists are not hashable, unless you make some strange subclass.

[ilevkivskyi]

This a known problem, and is not a purely mypy issue, but more like a typeshed one, see python/typeshed#2148. TBH, I don't see a problem in having few __hash__: None # type: ignore added to most used non-hashable classes.