Correct me if I’m wrong, but wouldn’t you have to unwrap every comparison then?
> On Jul 11, 2016, at 20:02, David Sweeris via swift-evolution > <[email protected]> wrote: > > Why not have them return a `Bool?`? If both arguments are non-nil, it can > return the results of the comparison, otherwise it can return nil. > > - Dave Sweeris > > On Jul 7, 2016, at 16:37, Jacob Bandes-Storch via swift-evolution > <[email protected] <mailto:[email protected]>> wrote: > >> These operators cause some potential for confusion: >> >> public func <<T : Comparable>(lhs: T?, rhs: T?) -> Bool >> public func ><T : Comparable>(lhs: T?, rhs: T?) -> Bool >> public func <=<T : Comparable>(lhs: T?, rhs: T?) -> Bool >> public func >=<T : Comparable>(lhs: T?, rhs: T?) -> Bool >> >> 1. The meaning of T? < T? is not immediately obvious (Why is nil < .some(x) >> for any x? Personally, my intuition says that Optional should only provide a >> partial order, with .none not being ordered w.r.t. .some(x).) >> >> 2. Even if the meaning is understood, it can be surprising when the (T?, T?) >> -> Bool version is used instead of (T, T) -> Bool. >> >> Prior discussion: >> - http://thread.gmane.org/gmane.comp.lang.swift.devel/2089 >> <http://thread.gmane.org/gmane.comp.lang.swift.devel/2089> >> - http://thread.gmane.org/gmane.comp.lang.swift.evolution/10095 >> <http://thread.gmane.org/gmane.comp.lang.swift.evolution/10095> >> - rdar:// <rdar://>16966712&22833869 >> - Replies to https://twitter.com/jtbandes/status/646914031433871364 >> <https://twitter.com/jtbandes/status/646914031433871364> >> >> In the swift-dev thread from May, Chris said: >> >> One of the ideas that Joe Pamer has been discussing is whether the implicit >> promotion from T to T? should be disabled when in an operator context. >> Doing so would fix problems like this, but making the code invalid. >> >> >> A change like this would be source-breaking, so if the core team has >> recommendations for how to handle these issues, now is probably the time to >> get it done. >> >> Jacob >> _______________________________________________ >> swift-evolution mailing list >> [email protected] <mailto:[email protected]> >> https://lists.swift.org/mailman/listinfo/swift-evolution >> <https://lists.swift.org/mailman/listinfo/swift-evolution> > _______________________________________________ > swift-evolution mailing list > [email protected] > https://lists.swift.org/mailman/listinfo/swift-evolution
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