Re: [swift-users] ⁨Is it possible to store a set of heterogeneous items with protocol?

Thanks for the detailed example. It makes sense. But the code can grow pretty quickly with just a few methods and a few concrete types. Also most are repetitive. I’ll try to incorporate this pattern when the use case is simple. But for more complex ones I guess I have to stick with classes for

Re: [swift-users] Is there any harm that an @escaping handler never called?

Glad to know the answer. And thank you, Slava and Daniel.​ Zhao Xin On Wed, Jul 12, 2017 at 7:53 AM, Daniel Dunbar wrote: > > On Jul 11, 2017, at 3:55 PM, Zhao Xin via swift-users < > swift-users@swift.org> wrote: > > For example, I have an async query, I pass it an

Re: [swift-users] ⁨Is it possible to store a set of heterogeneous items with protocol?

I would be tempted to use classes for this if you can use single inheritance. If you need multiple inheritance then use an enum and hand code the dispatch, a lot more work :(. E.G.: protocol A { func a() -> String } protocol B { func b() -> String } struct AB1: A, B, Hashable { func

Re: [swift-users] Is there any harm that an @escaping handler never called?

> On Jul 11, 2017, at 3:55 PM, Zhao Xin via swift-users > wrote: > > For example, I have an async query, I pass it an `@escaping resultHandler`. > If there is any results, the handler will run. However, if the result is > empty, the

Re: [swift-users] Is there any harm that an @escaping handler never called?

No, there is no requirement to invoke a closure at least once, escaping or not. Slava > On Jul 11, 2017, at 3:55 PM, Zhao Xin via swift-users > wrote: > > For example, I have an async query, I pass it an `@escaping resultHandler`. > If there is any results, the handler

[swift-users] Is there any harm that an @escaping handler never called?

For example, I have an async query, I pass it an `@escaping resultHandler`. If there is any results, the handler will run. However, if the result is empty, the `@escaping resultHandler` will never run. Is there any memory leak or something will happen if the `@escaping resultHandler` never runs?

Re: [swift-users] Exceptional values in the Comparable protocol

on Tue Jul 11 2017, Martin R wrote: > Thank you for the clarification! Sure, happy to help! -- -Dave ___ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users

Re: [swift-users] Exceptional values in the Comparable protocol

Thank you for the clarification! > On 10. Jul 2017, at 23:29, Dave Abrahams via swift-users > wrote: > > > on Sun Jul 09 2017, Martin R wrote: > >> The Comparable protocol requires that < and == impose a strict total >> order: exactly one of a==b, ab must hold

Re: [swift-users] ⁨Is it possible to store a set of heterogeneous items with protocol?

No it does not have to be a generic enum at all, as long you do not want extending the types from a diffrent module. Simply add a new enum case for each type you need, like `case string(String)`. You may also want to ask the wrapped type for it's hashValue so that it will hash correctly. --

Re: [swift-users] ⁨Is it possible to store a set of heterogeneous items with protocol?

NM, I think you meant this? enum Either { case Left(T1) case Right(T2) } > On 11 Jul 2017, at 9:06 PM, Glen Huang via swift-users > wrote: > > This sounds pretty interesting. > > But I can’t totally wrap my head around it. How do I "wrap types into

Re: [swift-users] ⁨Is it possible to store a set of heterogeneous items with protocol?

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 > wrote: > > If the solution you seek is not designed so

Re: [swift-users] ⁨Is it possible to store a set of heterogeneous items with protocol?

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

Re: [swift-users] ⁨Is it possible to store a set of heterogeneous items with protocol?

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

[swift-users] ⁨Is it possible to store a set of heterogeneous items with protocol?

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 }