<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>I have a patch that implements this proposal *except* this part. (aka () -> Void means 0 argument therefore { _ in } is a mismatch).</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">If we were to interpret tuple and the outer paren as described in this proposal, it should be consistent everywhere, therefore requires more consideration (separate proposal) and bigger change in the compiler.<br><br><div>Daniel Duan</div>Sent from my iPhone</div><div><br>On Jul 5, 2016, at 2:07 PM, Jordan Rose <<a href="mailto:jordan_rose@apple.com">jordan_rose@apple.com</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html charset=us-ascii"><br class=""><div><blockquote type="cite" class=""><div class="">On Jul 3, 2016, at 5:02, Vladimir.S 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=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: 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; float: none; display: inline !important;" class="">On 02.07.2016 4:20, Daniel Duan via swift-evolution wrote:</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: 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;" class=""><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: 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-size-adjust: auto; -webkit-text-stroke-width: 0px;" class=""><blockquote type="cite" class="">Vladimir.S via swift-evolution <swift-evolution@...> writes:<br class=""></blockquote><br class="">Following your conclusion, should this be legal as well?<br class=""><br class="">let f: () -> Void = { x in print(x) } // f() prints "()"<br class="">let f: (Int) -> Void = { x in print(x) } // f(5) prints "5"<br class=""><br class="">In other words, "0 argument" is an impossible scenario?<br class=""></blockquote><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: 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;" class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: 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; float: none; display: inline !important;" class="">I don't see problems here. ()->Void means (Void)->Void, there *is* one parameter of Void type, which we can omitted as it is empty tuple. So, if you want you can write f(()) or or let z = (); f(z); or just f(), so in closure definition you can have one argument or can have 0 defined arguments if the only argument is of type Void.</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: 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;" class=""></div></blockquote></div><br class=""><div class="">I already said this on the bug you filed, but I disagree quite strongly with this interpretation, based on <a href="https://github.com/apple/swift-evolution/blob/master/proposals/0029-remove-implicit-tuple-splat.md" class=""></a><a href="https://github.com/apple/swift-evolution/blob/master/proposals/0029-remove-implicit-tuple-splat.md" class="">SE-002</a>9. IMO, going from (()) to () is a form of tuple splat.</div><div class=""><br class=""></div><div class="">Jordan</div></div></blockquote></body></html>