<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=""><blockquote type="cite" class="">On May 6, 2016, at 3:15 PM, Joe Groff via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""></blockquote><div><blockquote type="cite" class=""><br class="Apple-interchange-newline"><div class=""><div class=""><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">On May 6, 2016, at 12:21 PM, Jacob Bandes-Storch via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""><br class="">Does this affect the ability to use "x as? Int" (and similar) when x is an NSNumber?<br class=""></blockquote><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">No, this only affects compile-time implicit conversions. I proposed changing the runtime behavior of dynamic casts in SE-0083:</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><a href="https://github.com/apple/swift-evolution/blob/master/proposals/0083-remove-bridging-from-dynamic-casts.md" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">https://github.com/apple/swift-evolution/blob/master/proposals/0083-remove-bridging-from-dynamic-casts.md</a></div></div></blockquote></div><br class=""><div class="">I’d just like to throw in that the ability to use “x as? Int” when x is an NSNumber is terrible.</div><div class=""><br class=""></div><div class=""><div class="">let num: AnyObject = NSNumber(int: 5)</div><div class=""><br class=""></div><div class="">let int = num as? Int<span class="Apple-tab-span" style="white-space:pre"> </span>// 5</div><div class="">let float = num as? Float<span class="Apple-tab-span" style="white-space:pre"> </span>// 5</div><div class="">let int32 = num as? Int32<span class="Apple-tab-span" style="white-space:pre"> </span>// nil!</div></div><div class=""><br class=""></div><div class="">Completely unexpected failure, and you’ll never know about it until runtime.</div><div class=""><br class=""></div><div class="">Charles</div><div class=""><br class=""></div></body></html>