Spurious "No overload variant matches argument types"

[chadrik]

I have an overloaded function that instantiates a class:

from typing import Any, Type, TypeVar, overload
T = TypeVar('T')

@overload
def make(cls: Type[T]) -> T:
    pass

@overload
def make() -> Any:
    pass

def make(cls=None):
    if cls:
        return cls()
    return object()

c = make(int)

reveal_type(c)

Type checking with mypy (using latest from master branch) results in the error:

[out]
a.py:17: error: No overload variant of "make" matches argument types [Overload(def (x: typing.SupportsInt =) -> builtins.int, def (x: Union[builtins.str, builtins.bytes], base: builtins.int =) -> builtins.int)]
a.py:19: error: Revealed type is 'Any'

Removing the overload prevents the error:

from typing import Type, TypeVar
T = TypeVar('T')

def make(cls: Type[T]) -> T:
    return cls()

c = make(int)

Is this a bug or user error?

thanks!

[JelleZijlstra]

Looks like a bug to me. I think it may be translating the type int to a callable incorrectly, so it no longer matches Type.

[ilevkivskyi]

Overloaded actual for Type[...]formal was just overlooked when implementing Type[...]. This would be essentially just a two-line fix.

[ilevkivskyi]

As I promised here is a fix #4037

[chadrik]

Thanks!