Non-actors isolated to an actor

[mattie]

I have had similar thoughts, and I think this is interesting!

But, have you had a look at this proposal here? I think it will have a pretty dramatic impact on exactly this kind of problem.

[Pitch] Inherit isolation by default for async functions

Hello, Swift evolution! SE-0338 specifies that nonisolated async functions never run on an actor's executor. This design decision was made to prevent unnecessary serialization and contention for the actor by switching off of the actor to run the nonisolated async function, and any new tasks it creates that inherit isolation. The actor is then free to make forward progress on other work. This behavior is especially important for preventing unexpected overhang on the main actor. However, based o…