[swift-evolution] ValueEnumerable protocol with derived implementation for enums

[Brent Royal-Gordon]

> I would suggest that ValuesEnumerable should expose allValues and the type of allValues should be a custom OptionSet implementation that iterates in declaration order.

That would make sense if OptionSet were a generic type which took any integer-ish RawRepresentable (which I've advocated before, although I sort of understand why we haven't gone that route), but it isn't, so I don't think that makes a lot of sense for Swift.

-- 
Brent Royal-Gordon
Architechies