> I don't see what that can possible get you that `Struct(x=int, y=str)` doesn't.
Using `Struct(x=int, y=str)` requires a metaclass, where `Struct[x=int, y=str]` does not.
Why would it require a metaclass? Rather than just:
class Struct:
def __init__(self, **kws): ...
Yes, that won't get you the MRO for T, but neither can __getitem__() on an entirely different object Struct.
A class factory is also an option, of course.