<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Reflection mechanisms in general would let one make things like Codable and Keypaths simply a library capability/protocol extension rather than the special case one trick pony it is now.<div class=""><br class=""></div><div class="">More than any other feature discussed, full access to meta data such as memory layouts is the thing I most miss from Objective C. </div><div class=""><br class=""></div><div class="">Given reflection/introspection, you can build KVC, Codable, and any number of other clever features yourself if you are so inclined.</div><div class=""><br class=""></div><div class="">Oh, and traits - want traits for composability.</div><div class=""><br class=""></div><div><blockquote type="cite" class=""><div class="">On Aug 25, 2017, at 11:43 AM, Joe Groff 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=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">These would all be great additional features to eventually add to key paths. I think reflection mechanisms centered on key paths like what you describe would be a superior replacement for most of what Mirror attempts to provide.</span></div></blockquote></div><br class=""></body></html>