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

[Tino Heth]

> Yes, I know it'd all be the epitome of annoying boilerplate code, but my point is that if someone wants to subclass something of yours, there's really not much you can do to stop them.
This would be fine: inheritance bad, composition good ;-)

The problems of this attitude just aren't visible now, because it isn't imposed on you.