NM, I think you meant this?
enum Either<T1, T2> {
case Left(T1)
case Right(T2)
}
> On 11 Jul 2017, at 9:06 PM, Glen Huang via swift-users
> <[email protected]> wrote:
>
> 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 <[email protected]
>> <mailto:[email protected]>> 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
>> ([email protected] <mailto:[email protected]>) 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 <[email protected]
>>>> <mailto:[email protected]>> 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
>>>> <[email protected] <mailto:[email protected]>> 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
>>>>> [email protected] <mailto:[email protected]>
>>>>> https://lists.swift.org/mailman/listinfo/swift-users
>>>>> <https://lists.swift.org/mailman/listinfo/swift-users>
>>>
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