<html><head><style>body{font-family:Helvetica,Arial;font-size:13px}</style></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">FWIW, not sure if it fits your desired outcome, but some time ago I’ve proposed the idea of `CustomOptionalConvertible` protocol:</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><a href="https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20151207/000918.html">https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20151207/000918.html</a> </div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">This could be used to extend the let binding syntax to any arbitrary type, as long as the user provides the valid translation to Optional<Type>.</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">The proposal, unfortunately, did not get a lot of attention at the time.</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">The main drawback to such a solution for your case is that CustomOptionalConvertible is an opt-in mechanism, so you’d need to write the implementation of CustomOptionalConvertible to each type you wish to let bind:</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">extension Type : CustomOptionalConvertible {</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><span class="Apple-tab-span" style="white-space:pre"> </span>typealias Wrapped = Type</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><span class="Apple-tab-span" style="white-space:pre"> </span>public var <span style="white-space: pre-wrap;">optional: Optional<Type> { get {</span></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><span style="white-space: pre-wrap;"><span class="Apple-tab-span" style="white-space:pre"> </span>return .Some(self)</span></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><span style="white-space: pre-wrap;"><span class="Apple-tab-span" style="white-space:pre"> </span>}}</span></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">}</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">Would the necessity for the above boilerplate be a show-stopper to you? </div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">If so, would you rather see the extension of let bind syntax as default on for all the types?</div> <div><br></div>Cheers,<div>Krzysztof<br> <div id="bloop_sign_1452149706960624896" class="bloop_sign"></div> <br><p class="airmail_on">On 7 January 2016 at 07:41:06, Russ Bishop via swift-evolution (<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>) wrote:</p> <blockquote type="cite" class="clean_bq"><span><div><div></div><div>I often want to bind variables to a specific scope, or perhaps I have three optionals I want to bind and one non-optional. (Often I need that non-optional value as part of a where condition check but not being able to bind it means I leak the variable to the outer scope).<br><br>Not being able to bind non-optionals breaks the flow of the code and forces me to make a minor context switch when it really doesn’t matter, nor does it aid code clarity. <br><br><br>Does anyone have strong thoughts about this? I tried searching the evolution repo and the mailing list and didn’t see anything.<br><br><br>—russ<br>_______________________________________________<br>swift-evolution mailing list<br>swift-evolution@swift.org<br>https://lists.swift.org/mailman/listinfo/swift-evolution<br></div></div></span></blockquote></div></body></html>