Union types are to enums as tuples are to structs. There's room for both in the language. Sometimes it makes sense to have a more formalized construct that has specific semantics (like an error type) and methods that operate upon that type. Sometimes, you just want an int OR a string.
On Sat, May 14, 2016 at 10:58 AM, Tino Heth via swift-evolution < swift-evolution@swift.org> wrote: > > > func f(obj: A&B&C) {..} > > if obj is A&B&C {...} > > obj2 = obj as! A&B&C > > > > (but I still don't understand real use case of things like (String | > Int)) > Ceylon has already been mentioned: It uses the concept for its optionals. > Swift uses enums, and those could be made obsolete by union types. > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution >
_______________________________________________ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/listinfo/swift-evolution