SE-0327: On Actors and Initialization

[Douglas_Gregor]

@DevAndArtist

The explicit global actor protection on an actor stored property would be disallowed, fine it'll be protected by the actor itself. What about other types, what's going to protect the properties if the implicit actor is gone?

I think the rule we really need here is that a stored property has the same isolation as its enclosing type: a stored property of an actor is isolated to that actor, a stored property of class is isolated to the global actor of that class (if it has one) or has no isolation.

@DevAndArtist

Last but not least, was it ever decided that actors will never gain inheritance? Not that I want/need that feature, but it feels a bit odd trying to eliminate convenience keyword on actors when the answer to that question might be undecided. If we'd ever introduce inheritance to actors, wouldn't they need convenience to have similar but complex delegation rules like classes?

Actors do not have inheritance today. If they were to gain inheritance in the future, we would not necessary have initializer inheritance, which came from Objective-C and is the root of the complex delegation patterns. Without initializer inheritance, the designated/convenience split is unnecessary and the whole model becomes simpler. So, I would prefer that we eliminate convenience from actors, and leave it as an oddity for classes.

Doug