> On Oct 21, 2016, at 12:23 PM, Tony Allevato via swift-evolution > <[email protected]> wrote: > > Now there's a caveat here worth discussing: would the intention of an > "enum-constrained protocol" be to define the *only* cases it can have, or > just the minimal set? The former would let you do some interesting generic > protocol-constrained exhaustive pattern matching. However, given that no > other use of protocols defines an *exact* set (you don't say these are the > *only* methods/properties that a conforming type can implement), I think it > would be a hard sell to apply a stronger restriction specifically to enums. > In any case, it feels to me like an enum restricted to "only these exact > cases" calls more for a generic enum rather than a protocol-based solution.
I would say it should define the minimal set, and any switching over the generic protocol type needs either a `default` or a `case _` clause to handle concrete types which have more cases than the protocol requires. - Dave Sweeris _______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
