[Python-ideas] Re: Structure Pattern for annotation

I guess you could work around this by exploiting the slicing operator: GenericClass[:(A, B)] It makes sense to use the : in the context of typing, but I can see how this syntax can be confusing. The least confusing implementation I could think of is to limit the use of GenericClass[:_] to tuples, lists, sets and dicts (and future callable type signatures?), i.e.; it should only be used for structural type pattern matching. Here is a simple demo: https://gist.github.com/jorenham/1c241a1cf33d2cc8235631b63fa8f279