I think this will cause more trouble. NewTypes should generally be compared by identity, so creating a new one is problematic. I don't have a better idea though.

I think this will cause more trouble. NewTypes should generally be compared by identity, so creating a new one is problematic. I don't have a better idea though.

@JelleZijlstra I think we can mutate __supertype__ attr of NewType. So impl will look like this:

    if isinstance(t, NewType):
        arg = ForwardRef(t.__supertype__) if isinstance(t.__supertype__, str) else t.__supertype__
        t.__supertype__ = _eval_type(arg, globalns, localns, recursive_guard)
        return t

What do you think about such option?

That's also problematic:

1. It's nice to keep all typing objects immutable, since mutable state is the root of much evil.
2. The globalns and localns in your code sample come from a specific call to get_type_hints. What if I call get_type_hints again later with a different namespace?

Possible solution can be add __eq__ implementation to typing.NewType. But it will go against identity compare.