"I think there's a sweet spot for a language that accepts mutability inside of actors, but only allows immutable objects to be sent as messages" Absolutely agr

"I think there's a sweet spot for a language that accepts mutability inside of actors, but only allows immutable objects to be sent as messages" Absolutely agree. I had great hopes an "Actor" type would be created in Swift, where every public function would be thread-safe, accept only "pure" structs / value objects, and which would automatically run on its own coroutine. Unfortunately the concurrency story seems completely abandoned for this language.