Generics as defaults

[genglandaer]

Bug Report

When you use a function as a default in a generic class, its types are not interpreted correctly

(A clear and concise description of what the bug is.)

To Reproduce

LINK TO GIST

Expected Behavior

When passing in a lambda to return the value passed in, it should interpret that the second generic type is the same as the first.

Actual Behavior

It is ok if you pass a lambda in the constructor. It throws an error if you have it as a default in the constructor.

main.py:8: error: Incompatible default for argument "parse_to" (default has type "Callable[[V], V]", argument has type "Callable[[V], K]") [assignment]
main.py:8: error: Incompatible return value type (got "V", expected "K") [return-value]

[hauntsaninja]

Duplicate of #3737