> On Feb 21, 2017, at 11:42 PM, David Hart via swift-evolution > <swift-evolution@swift.org> wrote: > > If we drop the idea of extending Any and AnyObject (which is out of scope), > does the fact that what is left is syntactic sugar make it unsuitable for > Swift 4? I remember Chris saying syntactic sugar is not the goal for Swift 4, > but this syntactic sugar looks really sweet (pun intended). >
It’s unlikely we’ll make it a priority to implement anything like that in the Swift 4 timeframe, but PRs are more than welcome ;-) Slava > On 22 Feb 2017, at 08:36, Douglas Gregor <dgre...@apple.com > <mailto:dgre...@apple.com>> wrote: > >> >> >> Sent from my iPhone >> >> On Feb 21, 2017, at 11:25 PM, David Hart via swift-evolution >> <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: >> >>> Yes, but it's not very discoverable. Plus, if the subclass existentials >>> proposal is accepted, it would actually allow us to do: >>> >>> class C {} >>> extension C & P1 {} >> >> ... which is >> >> extension P1 where Self: C1 {} >> >> >> Actually extending semantics (e.g. to extend Any or AnyObject) is a very >> large project that's out of scope. Without that, this is a small bit of >> syntactic sugar. >> >> - Doug >> >>> >>> On 22 Feb 2017, at 08:06, Jacob Bandes-Storch <jtban...@gmail.com >>> <mailto:jtban...@gmail.com>> wrote: >>> >>>> This works today: >>>> >>>> protocol P1{} >>>> protocol P2{} >>>> >>>> extension P1 where Self: P2 { >>>> func foo() {} >>>> } >>>> >>>> func bar(x: P1 & P2) { >>>> x.foo() >>>> } >>>> >>>> >>>> On Tue, Feb 21, 2017 at 10:53 PM, David Hart via swift-evolution >>>> <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: >>>> Hello list, >>>> >>>> Found out yesterday that you can’t extend all existentials in Swift: >>>> >>>> protocol P1 {} >>>> extension P1 {} >>>> // works as expected >>>> >>>> protocol P2 {} >>>> extension P1 & P2 {} >>>> // error: non-nominal type 'P1 & P2' cannot be extended >>>> >>>> extension Any {} >>>> // error: non-nominal type 'Any' cannot be extended >>>> >>>> extension AnyObject {} >>>> // error: 'AnyObject' protocol cannot be extended >>>> >>>> I’d like to write a proposal to lift some of those restrictions. But the >>>> question is: which should be lifted? P1 & P2 seems like an obvious case. >>>> But what about Any and AnyObject? Is there a design reason that we >>>> shouldn’t allow it? >>>> >>>> David. >>>> >>>> _______________________________________________ >>>> swift-evolution mailing list >>>> swift-evolution@swift.org <mailto:swift-evolution@swift.org> >>>> https://lists.swift.org/mailman/listinfo/swift-evolution >>>> <https://lists.swift.org/mailman/listinfo/swift-evolution> >>>> >>>> >>> _______________________________________________ >>> swift-evolution mailing list >>> swift-evolution@swift.org <mailto:swift-evolution@swift.org> >>> https://lists.swift.org/mailman/listinfo/swift-evolution >>> <https://lists.swift.org/mailman/listinfo/swift-evolution> > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution
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