I just saw a question which brought up something I didn't know about.
Apparently sometimes you have to call object.self in a place that looks like
you should just use "object." What does this usage mean?
for subclassObject in objects {
switch subclassObject.self { <--- Here, why not "subclassObject"
alone?
case is Subclass1:
doSomethingWith(subclassObject as! Subclass1)
case is Subclass2:
doSomethingWith(subclassObject as! Subclass2)
case is Subclass3:
doSomethingWith(subclassObject as! Subclass3)
default:
break
}
}
Thanks,
Rick
> On Jul 8, 2016, at 08:15 , Dan Loewenherz via swift-users
> <swift-users@swift.org> wrote:
>
> To my knowledge, you can’t do exactly what you’re trying to do, but this is
> close:
>
> for subclassObject in objects {
> switch subclassObject.self {
> case is Subclass1:
> doSomethingWith(subclassObject as! Subclass1)
>
> case is Subclass2:
> doSomethingWith(subclassObject as! Subclass2)
>
> case is Subclass3:
> doSomethingWith(subclassObject as! Subclass3)
>
> default:
> break
> }
> }
>
> On Fri, Jul 8, 2016 at 10:11 AM, Nate Birkholz via swift-users
> <swift-users@swift.org> wrote:
> This looks like it doesn't work (swift 2.x), but wanted to be sure it's not
> supported:
> class Superclass {}
> class Subclass1 : Superclass {}
> class Subclass2 : Superclass {}
> class Subclass3 : Superclass {}
>
> let sc1 = Subclass1()
> let sc2 = Subclass2()
> let sc3 = Subclass3()
>
> let objects : [Superclass] = [sc1, sc2, sc3]
>
> for subclassObject in objects {
> switch subclassObject {
> case let object = subclassObject as? Subclass1:
> doSomethingWith(object)
> case let object = subclassObject as? Subclass2:
> doSomethingWith(object)
> case let object = subclassObject as? Subclass3:
> doSomethingWith(object)
> default:
> return
> }
> }
>
> This gives an error, expecting a colon (:) after object on every case.
>
> I wanted to be sure I wasn't missing something in my syntax (nor some
> obvious-to-others reason this isn't supported) before going to swift
> evolution.
>
>
> --
> Nate Birkholz
>
> _______________________________________________
> swift-users mailing list
> swift-users@swift.org
> https://lists.swift.org/mailman/listinfo/swift-users
>
>
> _______________________________________________
> swift-users mailing list
> swift-users@swift.org
> https://lists.swift.org/mailman/listinfo/swift-users
--
Rick Mann
rm...@latencyzero.com
_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users
