<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">At least SR-103 is a legitimate bug that we would like to fix one day.<div class=""><br class=""></div><div class="">Slava<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Nov 5, 2017, at 1:27 AM, Goffredo Marocchi <<a href="mailto:panajev@gmail.com" class="">panajev@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div dir="auto" class=""><div class=""><span class=""></span></div><div class="">I would say that you kind of already entered a slippery slope when the extension to a protocol can add code / not just declare a behavioural contract and how it changes OOP approach (hence: <a href="https://bugs.swift.org/plugins/servlet/mobile#issue/SR-302" class="">https://bugs.swift.org/plugins/servlet/mobile#issue/SR-302</a> and <a href="https://bugs.swift.org/browse/SR-103" class="">https://bugs.swift.org/browse/SR-103</a> and <a href="https://bugs.swift.org/plugins/servlet/mobile#issue/SR-584" class="">https://bugs.swift.org/plugins/servlet/mobile#issue/SR-584</a>)</div><div class=""><br class=""></div><div class="">References:</div><div class=""><font class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><a href="https://nomothetis.svbtle.com/the-ghost-of-swift-bugs-future" class="">https://nomothetis.svbtle.com/the-ghost-of-swift-bugs-future</a> </span></font></div><div class=""><a href="https://www.raizlabs.com/dev/2016/12/swift-method-dispatch/" style="background-color: rgba(255, 255, 255, 0);" class="">https://www.raizlabs.com/dev/2016/12/swift-method-dispatch</a></div><div class=""><br class=""></div><div class=""><div class="">Sent from my iPhone</div><div class=""><br class="">On 5 Nov 2017, at 01:08, Slava Pestov <<a href="mailto:spestov@apple.com" class="">spestov@apple.com</a>> wrote:<br class=""><br class=""></div><blockquote type="cite" class=""><div class=""><span class=""></span><br class=""><span class=""></span><br class=""><blockquote type="cite" class=""><span class="">On Nov 4, 2017, at 1:32 AM, Goffredo Marocchi <<a href="mailto:panajev@gmail.com" class="">panajev@gmail.com</a>> wrote:</span><br class=""></blockquote><blockquote type="cite" class=""><span class=""></span><br class=""></blockquote><blockquote type="cite" class=""><span class=""></span><br class=""></blockquote><blockquote type="cite" class=""><span class=""></span><br class=""></blockquote><blockquote type="cite" class=""><span class="">Sent from my iPhone</span><br class=""></blockquote><blockquote type="cite" class=""><span class=""></span><br class=""></blockquote><blockquote type="cite" class=""><blockquote type="cite" class=""><span class="">On 4 Nov 2017, at 05:26, Slava Pestov via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</span><br class=""></blockquote></blockquote><blockquote type="cite" class=""><blockquote type="cite" class=""><span class=""></span><br class=""></blockquote></blockquote><blockquote type="cite" class=""><blockquote type="cite" class=""><span class="">Protocols define requirements, they don’t “add” things to the conforming type</span><br class=""></blockquote></blockquote><blockquote type="cite" class=""><span class=""></span><br class=""></blockquote><blockquote type="cite" class=""><span class="">I agree with this, but then this warrants a change for protocol extensions too. Would you be happy with the restriction that default method implementations are only available for value types and not for classes (as structs cannot share code any other way, it is the argument for that I seem to recall)?</span><br class=""></blockquote><span class=""></span><br class=""><span class="">Protocol extensions are in some sense just syntax sugar for defining new functions. Having a protocol conformance add storage to the conforming type is fundamentally different.</span><br class=""><span class=""></span><br class=""><span class="">Slava</span><br class=""><span class=""></span><br class=""><blockquote type="cite" class=""><span class=""></span><br class=""></blockquote><blockquote type="cite" class=""><span class=""></span><br class=""></blockquote><span class=""></span><br class=""></div></blockquote></div></div></div></blockquote></div><br class=""></div></body></html>