<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=""><div><blockquote type="cite" class=""><div class=""><br class="">On Feb 2, 2017, at 3:26 PM, Rex Fenley 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=""><div dir="ltr" class="">Hello, I believe there was some discussion about this quite awhile ago. I was wondering if there's any interest in including a protocol 'or' type that would be the intersection of two protocols. This could be really useful in situations where a framework that the user has no control over implements a portion of some often used protocol. Such as specialized collections from an Database framework that don't implement RangeReplaceableCollection but have a set of methods that are equivalent. The user can then implement a protocol that is the intersection of those set of methods and not duplicate code.</div></div></blockquote><div><br class=""></div><div>If the specialized collection in the database framework already provides functionality equivalent to `RangeReplaceableCollection` what you really want to do is just provide the conformance you’re looking for in an extension:</div><div><br class=""></div><div>extension SpecializedDatabaseCollection: RangeReplaceableCollection {</div><div> // if necessary, provide forwarding wrappers where the member names don’t match up.</div><div>}</div><div><br class=""></div><div>But in a case like this the framework itself really should provide this conformance out of the box. If they didn’t, maybe there is a good reason so you would want to find out why it wasn’t provided.</div><div><br class=""></div><div>Is there something you’re hoping to do that you can’t solve by simply extending the framework types?</div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class=""><br class=""></div><div class="">Simplified example:</div><div class=""><br class=""></div><div class="">protocol Animal {</div><div class=""> var hasEars: Bool { get }</div><div class=""> func grow()</div><div class="">}</div><div class=""><br class=""></div><div class=""><div class="">protocol Plant {</div><div class=""> var isGreen: Bool { get }</div><div class=""> func grow()</div><div class="">}</div><div class=""><br class=""></div><div class="">protocol LivingThing = Plant | Animal // or a different syntax</div><div class=""><br class=""></div><div class="">LivingThing's is as follows</div><div class="">{</div><div class=""> func grow()</div><div class="">}</div></div></div></div></blockquote><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class=""><div class=""><br class=""></div>-- <br class=""><div class="gmail_signature"><div dir="ltr" class=""><span class=""><div style="line-height: 1.15; margin-top: 0pt; margin-bottom: 0pt;" class=""><span style="font-size:16px;font-family:arial;background-color:transparent;font-style:italic;vertical-align:baseline;white-space:pre-wrap" class="">Rex Fenley</span><span style="font-size:16px;font-family:arial;background-color:transparent;vertical-align:baseline;white-space:pre-wrap" class=""> </span><span style="font-size:11px;font-family:arial;color:rgb(153,153,153);background-color:transparent;vertical-align:baseline;white-space:pre-wrap" class="">|</span><span style="line-height:1.15;font-family:arial;color:rgb(153,153,153);background-color:transparent;vertical-align:baseline;white-space:pre-wrap" class=""> </span><span style="font-size:11px;font-family:arial;color:rgb(153,153,153);background-color:transparent;vertical-align:baseline;white-space:pre-wrap" class="">IOS DEVELOPER</span><br class=""></div></span><span class=""><br class=""><div style="line-height: 1.15; margin-top: 0pt; margin-bottom: 0pt;" class=""><span style="font-size:11px;font-family:arial;color:rgb(153,153,153);vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class=""><img src="https://lh5.googleusercontent.com/xMgzw3JkFL3DLkdwyq0WxJzKs_XP57gVVCaBMvgi1FKCjSeue0xdx3JZeCWBlxN4KRHhHOfdvJbc1N-AjTwXcKIq4cjJg9H7iaFpQ8WbO4N3c9Y5dzi19cPOs_owPquuqw" width="250px;" height="53px;" style="border: none;" class=""></span></div><div style="line-height: 1.15; margin-top: 0pt; margin-bottom: 0pt;" class=""><a href="https://www.remind.com/" style="text-decoration:none" target="_blank" class=""><span style="font-size:11px;font-family:arial;color:rgb(17,85,204);font-weight:bold;text-decoration:underline;vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class="">Remind.com</span></a><span style="font-family:arial;vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class=""> </span><span style="font-size:11px;font-family:arial;vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class="">| </span><a href="http://blog.remind.com/" style="text-decoration:none" target="_blank" class=""><span style="font-size:11px;font-family:arial;color:rgb(17,85,204);text-decoration:underline;vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class="">BLOG</span></a><span style="font-size:11px;font-family:arial;vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class=""> | </span><a href="https://twitter.com/remindhq" style="text-decoration:none" target="_blank" class=""><span style="font-size:11px;font-family:arial;color:rgb(17,85,204);text-decoration:underline;vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class="">FOLLOW US</span></a><span style="font-size:11px;font-family:arial;vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class=""> | </span><span style="font-family:arial;vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class=""> </span><span style="text-decoration:underline;font-size:11px;font-family:arial;color:rgb(17,85,204);vertical-align:baseline;white-space:pre-wrap;background-color:transparent" class=""><a href="https://www.facebook.com/remindhq" style="text-decoration:none" target="_blank" class="">LIKE US</a></span></div></span></div></div>
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