"Actors are reference types, but why classes?"

[Chris_Lattner3 (Chris Lattner)]

@gwendal.roue

I think the point of Chris is to reverse the burden of proof. It is not necessary to prove that inheritance can be avoided in order to move forward with a simplified actor model. Instead, people that need actor inheritance have to convince that it is missing, in a classic evolution process (amend this pitch, or in the future bring a new pitch, implementation, proposal).

Yes, this is a good way to look at it. Unless there is a clear and compelling reason to allow subclassing, we shouldn't.

@jeremyabannister

Is it possible that an actor struct would just be a degenerate case where there is no thread-safety enforcement to be done? In which case "actor" would be an attribute that is orthogonal to the reference/value dichotomy?

I don't know what an "actor struct" would be useful. structs can be copied around, and each copy would have to create its own queue. One could define such a model I guess, but I don't see how it would be practical or useful to solve problems.

@kiel

On this proposal, can arbitrary extensions be made on actor types?

Yep, just like any other nominal type.

-Chris