[Concurrency] Actors & actor isolation

[anandabits (Matthew Johnson)]

@John_McCall

I think if we were going to allow this sort of actor-generics, it would need to support actor classes as well; can you figure out a way to make that work?

The Store in my example is an actor class so I don’t understand the question. Can you elaborate?

Another example from my library is:

final actor class TupleStore2<Store0: GlobalActor, Store1: GlobalActor>: GlobalActor
  where Store0.ActorContext == Store1.ActorContext
{
    typealias ActorContext = Store0.ActorContext
}

In my library TupleStore2 is actually a struct. Ideally a heap allocation could be avoided but I'm not sure how that could be expressed in terms of the current pitch.