<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>I'm against it, unless structs can have "WeakCollectionType" properties (which seems like it'd necessarily involve some of that compiler magic we're trying to avoid).<br><br>If reference/value semantics weren't tied to struct/class, I'd care a lot less.</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">I also wouldn't object to removing them from structs, but then adding a "strass" object classification for when you need weak inside a value-semantics object.<br><br>-Dave Sweeris<br><br>Sent from my iPhone</div><div><br>On Jan 29, 2016, at 17:56, Jordan Rose via swift-dev <<a href="mailto:swift-dev@swift.org">swift-dev@swift.org</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html charset=utf-8">Hi, everyone. What do you think about dropping support for 'weak' in struct properties? This would fix a semantic issue—'let' structs containing weak properties won't change out from under you—and (AFAICT) would make all values trivially movable, which is a great quality to have.<br class=""><div class=""><br class=""></div><div class="">This wouldn't change local variables, top-level variables, or class properties, just structs. It <i class="">would</i> make having an array of weak references a little harder, but honestly we should have proper weak-supporting collections anyway; as I understand it the behavior you usually want is auto-compacting rather than leaving a hole. (Evidence: Cocoa has NSHashTable for weak sets and NSMapTable for dictionaries with weak keys and/or values; there's no variant of NSArray that supports weak references other than by making a custom CFArray and being very very careful how you access it.)</div><div class=""><br class=""></div><div class="">Anyway, thoughts? It's not really my department but it cleans up the same areas that are being affected by struct resilience.</div><div class="">Jordan</div><div class=""><br class=""></div><div class="">P.S. I know this would have to go through swift-evolution for real. I just want to know if it's a silly idea to begin with.</div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>swift-dev mailing list</span><br><span><a href="mailto:swift-dev@swift.org">swift-dev@swift.org</a></span><br><span><a href="https://lists.swift.org/mailman/listinfo/swift-dev">https://lists.swift.org/mailman/listinfo/swift-dev</a></span><br></div></blockquote></body></html>