<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></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 17, 2015, at 9:44 AM, Jordan Rose 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 class="" style="font-family: Helvetica; font-size: 12px; 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;">It's intended to be required all the time; the cases where it's not required are a bug. (I think it's just single-argument function calls, but I could be wrong.)</div><div class="" style="font-family: Helvetica; font-size: 12px; 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;"><br class=""></div><div class="" style="font-family: Helvetica; font-size: 12px; 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;">Again, it's intended to allow the compiler to produce better diagnostics for "let x = SomeType" when you really meant "let x: SomeType". I can't think of any other examples where the error messages wouldn't be obvious, but with a declaration the diagnostics may be somewhere unrelated to the issue. (Especially if it's a property.)</div></div></blockquote><br class=""></div><div>There's also a syntactic ambiguity with < > being both operators and generic parameter brackets that we resolve by requiring generic parameters in expression context to always be followed by a paren, as in a construction Foo<Bar>(), or by a dot, as in Foo<Bar>.member. C# does the same.</div><div><br class=""></div><div>-Joe</div><br class=""></body></html>