[swift-evolution] Handling unknown cases in enums [RE: SE-0192]

[Jean-Daniel]

> Le 10 janv. 2018 à 23:58, Howard Lovatt via swift-evolution <swift-evolution at swift.org> a écrit :
> 
> Two points:
> 
> 1. I like Chris’s suggestion of #unknown and in particular that it is distinct from default. 
> 
> 2. All the discussion is about a framework adding a case, what about when a framework deletes a case?

This is a binary breaking change (just like removing an existing function or method).