Shared via mypy Playground

main.py

from typing import Iterable


def fun[T](values: Iterable[T], value: list[T]) -> tuple[T | None, T | None]:
    ...
    return None, None


values: Iterable[int]
my_list: list[int]

result = fun(values, my_list)  # works fine
m, n = result

a, b = fun(values, my_list)  # raises error in mypy