It was new in Swift 2 I think. Didn't use it yet. But it's basically a single case statement lifted from switch, nothing more. But enums and switch statements c

It was new in Swift 2 I think. Didn't use it yet. But it's basically a single case statement lifted from switch, nothing more. But enums and switch statements can be really complex beasts by themselves in Swift. If Rust only allows it on enums that would be extremely weird. In a switch statement I sometimes want to switch on the object, then see if I'm allowed to unwrap it to a certain class and immediately use it afterwards. Useful for parsing an array of mixed object types that should be processed differently. But I honestly think Swift allows people to write elaborate illegible codegolf-y bullshit sometimes. Sometimes the Swift compiler still chokes on too complex expressions and you need to add some explicit types or separate out in several statements what you were trying to do in one statement. Usually a good warning that your code is hard to read even by humans.