<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=""><br class=""><div><blockquote type="cite" class=""><div class="">On Dec 15, 2015, at 10:02 AM, Thorsten Seitz <<a href="mailto:tseitz42@icloud.com" class="">tseitz42@icloud.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="" style="font-family: AvenirNext-Regular; font-size: 15px; font-style: normal; font-variant: 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; margin: 0px; line-height: normal;">Shouldn’t we just narrow the type of protocols with associated types and/or Self types when the protocol is used as a type?</div><br class="Apple-interchange-newline"></div></blockquote></div><div class=""><br class=""></div>Then you have the “P doesn’t conform to P” problem, which is too crazy to live. A recent internal discussion led to the idea that we should have notation for the existentially-viable subset of a protocol, so you could always make <font face="Menlo" class="">Array<existential P></font> but not necessarily <font face="Menlo" class="">Array<P> </font>for an arbitrary protocol <span style="font-family: Menlo;" class="">P</span>. Just one way to address this use-case, of course.<div class=""><br class=""><div class="">
-Dave<div class=""><br class=""></div><br class="Apple-interchange-newline">
</div>
<br class=""></div></body></html>