This sounds pretty interesting. But I can’t totally wrap my head around it. How do I "wrap types into enum cases”? Could you provide a sample code? Thanks.
> On 11 Jul 2017, at 8:50 PM, Adrian Zubarev <adrian.zuba...@devandartist.com> > wrote: > > If the solution you seek is not designed so that the module user can extend > the set of types then you could wrap your types into enum cases and use the > enum for your set. ;) When Swift will support anonymous enum cases, this will > be an elegant solution to these type of things. > > -- > Adrian Zubarev > Sent with Airmail > Am 11. Juli 2017 um 14:46:12, Glen Huang via swift-users > (swift-users@swift.org <mailto:swift-users@swift.org>) schrieb: > >> Thanks for bringing AnyHashable to my attention. >> >> It works, but the types are now erased. I want to have a union of the two >> sets because I want to loop over it to treat each contained item as Named, >> so I can process them as though they are of the same type. Is this type of >> use case really should be addressed using super class? >> >>> On 11 Jul 2017, at 7:38 PM, Howard Lovatt <howard.lov...@gmail.com >>> <mailto:howard.lov...@gmail.com>> wrote: >>> >>> You can have a set of AnyHashable: >>> >>>> var item = Set<AnyHashable>() >>>> item.insert(AnyHashable(Foo())) >>>> item.insert(AnyHashable(Bar())) >>> >>> Depends what you will do with the set if this is viable or not. You can >>> also use classes and ObjectID. >>> >>> You might want this though: >>> >>>> var item = [AnyHashable: Any] >>> extension Dictionary where Key == AnyHashable, Value: Hashable { >>> func insert(_ value: Value) { >>> self[AnyHashable(value)] == value >>> } >>> } >>>> item.insert(Foo()) >>>> item.insert(Bar()) >>> >>> So you get at the stored value. >>> >>> -- Howard. >>> >>> On 11 Jul 2017, at 8:09 pm, Glen Huang via swift-users >>> <swift-users@swift.org <mailto:swift-users@swift.org>> wrote: >>> >>>> Hi, >>>> >>>> I want to store some heterogeneous items all conform to a protocol inside >>>> a set, is it something possible to do in swift? >>>> >>>> I tried this example: >>>> >>>> ``` >>>> protocol Named: Hashable { >>>> var name: String { get } >>>> } >>>> >>>> extension Named { >>>> var hashValue: Int { >>>> return name.hashValue >>>> } >>>> >>>> static func ==(lhs: Self, rhs: Self) -> Bool { >>>> return lhs.name == rhs.name >>>> } >>>> } >>>> >>>> struct Foo: Named { >>>> var name = "foo" >>>> } >>>> >>>> struct Bar: Named { >>>> var name = "bar" >>>> } >>>> >>>> var item = Set<Named>() >>>> item.insert(Foo()) >>>> item.insert(Bar()) >>>> ``` >>>> >>>> But it failed at `Set<Named>()` where it complained "Using 'Named' as a >>>> concrete type conforming to protocol 'Hashable' is not supported”. >>>> >>>> After watching the WWDC session "Protocol-Oriented Programming in Swift” >>>> by Dave Abrahams, I try to use protocols whenever possible. But I can’t >>>> seem to overcome this barrier. Set.Element must confirm to Hashable, which >>>> inherits from Equatable, which has self requirement, which ultimately >>>> means that Set.Element all must be of the same type. So it seems it’s >>>> impossible to have heterogeneous items using protocol. Is that the case? >>>> >>>> My use case is this: >>>> >>>> I have an object that can contain two sets of other objects: >>>> >>>> ``` >>>> class Parent { >>>> var foos: Set<Foo> >>>> var bars: Set<Bar> >>>> } >>>> ``` >>>> >>>> I want to define a computed property “all” that is the union of the two >>>> sets. Foo and Bar conform to the same protocol. I wonder what return type >>>> I should use for the union? Do I have to go back to OOP and define a super >>>> class for Foo and Bar? >>>> >>>> Thanks. >>>> _______________________________________________ >>>> swift-users mailing list >>>> swift-users@swift.org <mailto:swift-users@swift.org> >>>> https://lists.swift.org/mailman/listinfo/swift-users >>>> <https://lists.swift.org/mailman/listinfo/swift-users> >> >> _______________________________________________ >> swift-users mailing list >> swift-users@swift.org >> https://lists.swift.org/mailman/listinfo/swift-users
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