[swift-evolution] [swift-evolution-announce] [Review] SE-0117: Default classes to be non-subclassable publicly

[Paul Cantrell]

> On Jul 5, 2016, at 8:45 PM, Brent Royal-Gordon via swift-evolution <swift-evolution at swift.org> wrote:
> 
> I think Kevin Lundberg is right to worry about testability, but I don't think that has to prevent this change. Instead, we should permit `@testable` imports to subclass/override things that are not publicly subclassable/overridable, and thus a module built with "Enable Testability" on can't actually assume there are no subclasses/overrides of `internal` classes/members even if it doesn't see any.

+1 to this. To me, @testable means “import as if it were internal to this module.”

P