"Actors are reference types, but why classes?"

[Douglas_Gregor]

@Chris_Lattner3

This is the third major memory safety problem of the base proposal (after actor sendable and global variable semantics). The original actor proposal attempts to solve it by adding some limitations around non-actor requirements, adds attributes to methods, and adds some (weird to me) rules around let s that don't seem sound. I personally don't think this is the best path.

We haven't seen a second revision of the actors proposal yet, so I'm waiting for that. If needed, I'll write an "actors vs sync requirements" white paper to capture some of the tradeoffs and thoughts here. There are a couple of ways to solve the generality and soundness problem with different tradeoffs.

I would much prefer that you provide an example that you believe to be unsound, and I can use that as a way to teach interested folks how the actor proposal maintains soundness. That will help me understand what in the proposal didn't come across well (or if there actually is a hole in the soundness of the model). It wouldn't make a lot of sense to write a white paper based on a misunderstanding of the proposed model.

Doug