What's the difference between a protocol extended from AnyObject and a class-only protocol?

Question

Both this declaration

protocol SomeProtocol : AnyObject {
}

and this declaration

protocol SomeProtocol : class {
}
<         


        

Answer 1

This was answered by an official Swift dev (Slava_Pestov) on the Swift forums. Here is the summary:

• You should use AnyObject (protocol SomeProtocol: AnyObject).

• AnyObject and class are equivalent. There is no difference.

• class will eventually be deprecated.