Proposal link: https://github.com/apple/swift-evolution/blob/master/proposals/0153-compensate-for-the-inconsistency-of-nscopyings-behaviour.md Reply text:
However, occasionally a constructor might be non-copying on purpose, so we'll need a way to disable the warning. How about the determination method mentioned in the proposal: ... if developers are performing an assignment operation from within an initializer between a property declared as @NSCopyingand an instance of a protocol conforming class. That is, there are two key factors determining whether a fixable error or warning should be emitted: If the destination property has been declared as @NSCopying in class definition If the source value conforms to <NSCopying> protocol Once both are true, then what compiler can be sure about is that developer definitely missed the required manual copy invocation and it would emit either an error or a warning correspondingly. Otherwise, compiler would not complain of anything and would just leave the decision up to developers. > On 18 Feb 2017, at 18:16, Brent Royal-Gordon via swift-evolution > <swift-evolution@swift.org> wrote: > >> On Feb 17, 2017, at 3:18 PM, Douglas Gregor <dgre...@apple.com> wrote: >> >> https://github.com/apple/swift-evolution/blob/master/proposals/0153-compensate-for-the-inconsistency-of-nscopyings-behaviour.md >> >> • What is your evaluation of the proposal? > > I think a warning is very appropriate. > > However, occasionally a constructor might be non-copying on purpose, so we'll > need a way to disable the warning. A few possibilities: > > * Use .self on the value > * Parenthesize the value > * Parenthesize the variable > > I don't favor using compiler magic. Too spooky. > >> • Is the problem being addressed significant enough to warrant a change >> to Swift? > > Yeah, that's a pretty easy mistake to make. > >> • Does this proposal fit well with the feel and direction of Swift? > > Yes. Swift usually tries to help you avoid mistakes. > >> • If you have used other languages or libraries with a similar feature, >> how do you feel that this proposal compares to those? > > N/A. > >> • How much effort did you put into your review? A glance, a quick >> reading, or an in-depth study? > > Quick reading. > > -- > Brent Royal-Gordon > Architechies > > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution
smime.p7s
Description: S/MIME cryptographic signature
_______________________________________________ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/listinfo/swift-evolution
