<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">I’d only +1 this proposal if we can perform an implicit conversion. From SE-0116:</div><div class=""><br class=""></div><div class=""><blockquote type="cite" class=""><span style="color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'; font-size: 16px; background-color: rgb(255, 255, 255);" class="">The user model for this type would ideally align with our long-term goal of supporting </span><code style="box-sizing: border-box; font-family: Consolas, 'Liberation Mono', Menlo, Courier, monospace; font-size: 13.600000381469727px; padding: 0.2em 0px; margin: 0px; background-color: rgba(0, 0, 0, 0.0392157); border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; color: rgb(51, 51, 51);" class="">Hashable</code><span style="color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'; font-size: 16px; background-color: rgb(255, 255, 255);" class=""> existentials directly, so the type deserves some short-term compiler support to help us get there.</span></blockquote></div><div class=""><br class=""></div><div class="">I read that as meaning that the interface should look as close as possible to what using a raw “Hashable” would look like, and that some short-term complier magic to achieve that would be acceptable. As far as that goes:</div><div class=""><br class=""></div><div class="">- unwrapping is functionally equivalent (upcasting from Any today, in the future from Hashable, but when upcasting all that matters is the destination type so NFC)</div><div class="">- wrapping is too verbose:</div><div class=""><br class=""></div><div class=""><blockquote type="cite" class=""><pre style="box-sizing: border-box; font-family: Consolas, 'Liberation Mono', Menlo, Courier, monospace; font-size: 13.600000381469727px; margin-top: 0px; margin-bottom: 0px; line-height: 1.45; word-wrap: normal; padding: 16px; overflow: auto; background-color: rgb(247, 247, 247); border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; word-break: normal; color: rgb(51, 51, 51);" class=""><span class="pl-c" style="box-sizing: border-box; color: rgb(150, 152, 150);">/// let descriptions: [AnyHashable : Any] = [</span>
<span class="pl-c" style="box-sizing: border-box; color: rgb(150, 152, 150);">/// AnyHashable("😄"): "emoji",</span>
<span class="pl-c" style="box-sizing: border-box; color: rgb(150, 152, 150);">/// AnyHashable(42): "an Int",</span>
<span class="pl-c" style="box-sizing: border-box; color: rgb(150, 152, 150);">/// AnyHashable(Int8(43)): "an Int8",</span>
<span class="pl-c" style="box-sizing: border-box; color: rgb(150, 152, 150);">/// AnyHashable(Set(["a", "b"])): "a set of strings"</span>
<span class="pl-c" style="box-sizing: border-box; color: rgb(150, 152, 150);">/// ]</span></pre></blockquote><div class=""><br class=""></div></div><div class="">That would be a big regression in readability, IMO. Previously, you could declare those keys without the “AnyHashable” wrapper, and the bridging magic would turn Int -> NSNumber because that’s the way to make an Int conform to NSObject. It should be possible to teach the compiler how to turn a Hashable in to an AnyHashable implicitly.</div><div class=""><br class=""></div><div class="">But yeah, if we can do an implicit conversion, it’s a 👍 from me</div><div class=""><br class=""></div><div class="">Karl</div><br class=""><div><blockquote type="cite" class=""><div class="">On 24 Jul 2016, at 00:26, Chris Lattner via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Hello Swift community,<br class=""><br class="">The review of "SE-0131: Add AnyHashable to the standard library" begins now and runs through July 25. This proposal is a bit unusual, since it is a late additive proposal. The reason we need to do something here is as a critical part of "SE-0116: Import Objective-C id as Swift Any type”, enabling importing untyped NSDictionary's and NSSet’s properly. The core team considers this already conceptually approved for Swift 3 as part of SE-0116, but would greatly appreciate feedback on the details of the proposed design.<br class=""><br class="">The proposal is available here:<br class=""><br class=""><span class="Apple-tab-span" style="white-space:pre"> </span><a href="https://github.com/apple/swift-evolution/blob/master/proposals/0131-anyhashable.md" class="">https://github.com/apple/swift-evolution/blob/master/proposals/0131-anyhashable.md</a><br class=""><br class="">Reviews are an important part of the Swift evolution process. All reviews should be sent to the swift-evolution mailing list at<br class=""><br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>https://lists.swift.org/mailman/listinfo/swift-evolution<br class=""><br class="">or, if you would like to keep your feedback private, directly to the review manager.<br class=""><br class="">What goes into a review?<br class=""><br class="">The goal of the review process is to improve the proposal under review through constructive criticism and contribute to the direction of Swift. When writing your review, here are some questions you might want to answer in your review:<br class=""><br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>* What is your evaluation of the proposal?<br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>* Is the problem being addressed significant enough to warrant a change to Swift?<br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>* Does this proposal fit well with the feel and direction of Swift?<br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>* If you have used other languages or libraries with a similar feature, how do you feel that this proposal compares to those?<br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>* How much effort did you put into your review? A glance, a quick reading, or an in-depth study?<br class=""><br class="">More information about the Swift evolution process is available at<br class=""><br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>https://github.com/apple/swift-evolution/blob/master/process.md<br class=""><br class="">Thank you,<br class=""><br class="">-Chris Lattner<br class="">Review Manager<br class=""><br class=""><br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class="">swift-evolution@swift.org<br class="">https://lists.swift.org/mailman/listinfo/swift-evolution<br class=""></div></div></blockquote></div><br class=""></body></html>