<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>IIUC (which shouldn't be assumed on your part) the difference is that any types which conform to both `A` and `B` will <i>automatically</i> conform to `CProtocol` as well, but not `C`. I suspect the "automatic conformance" bit is why we don't currently allow it.</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">- Dave Sweeris</div><div id="AppleMailSignature"><br></div><div>On Jun 19, 2017, at 13:44, Jon Shier via swift-users <<a href="mailto:swift-users@swift.org">swift-users@swift.org</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html charset=utf-8">What I usually do here is:<div class="">typealias CProtocol = A & B</div><div class="">protocol C: CProtocol { } // or just A & B directly, I think</div><div class="">extension C {}</div><div class=""><br class=""></div><div class="">So it’s a bit silly to me.</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Jon</div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Jun 19, 2017, at 3:44 PM, Slava Pestov via swift-users <<a href="mailto:swift-users@swift.org" class="">swift-users@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi Steven,<div class=""><br class=""></div><div class=""><div class=""><blockquote type="cite" class=""><div class="">On Jun 19, 2017, at 11:44 AM, Steven Brunwasser via swift-users <<a href="mailto:swift-users@swift.org" class="">swift-users@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div id="bloop_customfont" style="font-family: Helvetica, Arial; font-size: 13px; 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; margin: 0px;" class="">Is this error intentional, or a bug?</div></div></blockquote><div class=""><br class=""></div>It’s intentional. We could add support for this as an extra bit of sugar, but note that</div><div class=""><br class=""><blockquote type="cite" class=""><div id="bloop_customfont" style="font-family: Helvetica, Arial; font-size: 13px; 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; margin: 0px;" class="">Since <span class="" style="color: rgb(4, 51, 255); font-family: Menlo; font-size: 11px;">extension</span><span class="" style="font-family: Menlo; font-size: 11px;"> </span><span class="" style="font-family: Menlo; font-size: 11px; color: rgb(52, 149, 175);">A</span><span class="" style="font-family: Menlo; font-size: 11px;"> </span><span class="" style="color: rgb(4, 51, 255); font-family: Menlo; font-size: 11px;">where</span><span class="" style="font-family: Menlo; font-size: 11px;"> </span><span class="" style="color: rgb(4, 51, 255); font-family: Menlo; font-size: 11px;">Self</span><span class="" style="font-family: Menlo; font-size: 11px;">: B</span> is the same as <span class="" style="color: rgb(4, 51, 255); font-family: Menlo; font-size: 11px;">extension</span><span class="" style="font-family: Menlo; font-size: 11px;"> </span><span class="" style="font-family: Menlo; font-size: 11px; color: rgb(52, 149, 175);">B</span><span class="" style="font-family: Menlo; font-size: 11px;"> </span><span class="" style="color: rgb(4, 51, 255); font-family: Menlo; font-size: 11px;">where</span><span class="" style="font-family: Menlo; font-size: 11px;"> </span><span class="" style="color: rgb(4, 51, 255); font-family: Menlo; font-size: 11px;">Self</span><span class="" style="font-family: Menlo; font-size: 11px;">: A</span>,</div></blockquote><br class=""></div><div class="">This is not quite true.</div><div class=""><br class=""></div><div class="">Slava</div><br class=""></div></div>_______________________________________________<br class="">swift-users mailing list<br class=""><a href="mailto:swift-users@swift.org" class="">swift-users@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-users">https://lists.swift.org/mailman/listinfo/swift-users</a><br class=""></div></blockquote></div><br class=""></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>swift-users mailing list</span><br><span><a href="mailto:swift-users@swift.org">swift-users@swift.org</a></span><br><span><a href="https://lists.swift.org/mailman/listinfo/swift-users">https://lists.swift.org/mailman/listinfo/swift-users</a></span><br></div></blockquote></body></html>