<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=""><i class="">Int?</i> is not Equatable, b. You would have to use a non-optional. <div class=""><br class=""></div><div class="">Under the hood, Optionals are actually an Enum with two cases, <i class="">None</i>, and <i class="">Some<T></i>. <i class="">func ==(lhs: Int?, rhs: Int?)</i> must be designed essentially as a switch statement to handle each possibility. <br class=""><div class="">
--<br class="">Chris McIntyre<br class=""><br class=""><br class=""><br class="">
</div>
<br class=""><div><blockquote type="cite" class=""><div class="">On Feb 29, 2016, at 9:24 AM, Rudolf Adamkovič via swift-users <<a href="mailto:swift-users@swift.org" class="">swift-users@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="margin: 0px; line-height: normal;" class=""><span style="font-size: 11px; font-family: Menlo;" class="">Hi everyone!</span></div><div style="margin: 0px; line-height: normal;" class=""><font face="Menlo" class=""><span style="font-size: 11px;" class=""><br class=""></span></font></div><div style="margin: 0px; line-height: normal;" class=""><font face="Menlo" class=""><span style="font-size: 11px;" class="">I have a generic class similar to this one:</span></font></div><div style="margin: 0px; line-height: normal;" class=""><font face="Menlo" class=""><span style="font-size: 11px;" class=""><br class=""></span></font></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">class</span> C<T: Equatable> {</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""> <span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span> t: <span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">T</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""> <span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">init</span>(t: <span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">T</span>) { <span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">self</span>.<span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">t</span> = t }</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class="">}</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class="">When try to wrap ‘Int?' inside, I get the following error:</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; min-height: 13px;" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span> a = C<<span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span>?>(t: <span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">nil</span>) <span style="color: rgb(0, 132, 0);" class="">// ERROR: Type "Int?" does not conform to protocol 'Equatable'</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; min-height: 13px;" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; min-height: 13px;" class="">Yet when I try to compare two ‘Int?’ values, everything works:</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; min-height: 13px;" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span> a: <span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span>? = <span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">5</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span> b: <span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span>? = <span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">6</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; min-height: 13px;" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(0, 132, 0);" class=""><span style="color: rgb(187, 44, 162);" class="">let</span> c = <span style="color: rgb(79, 129, 135);" class="">a</span> == <span style="color: rgb(79, 129, 135);" class="">b</span><span style="color: rgb(79, 129, 135);" class=""> </span>// NO ERROR</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(0, 132, 0);" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(0, 132, 0);" class=""><div style="margin: 0px; line-height: normal; min-height: 13px;" class="">So, is ‘Int?' equatable or not?</div><div style="margin: 0px; line-height: normal; min-height: 13px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal; min-height: 13px;" class="">Thanks!</div><div style="margin: 0px; line-height: normal; min-height: 13px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal; min-height: 13px;" class="">R+</div></div></div>_______________________________________________<br class="">swift-users mailing list<br class=""><a href="mailto:swift-users@swift.org" class="">swift-users@swift.org</a><br class="">https://lists.swift.org/mailman/listinfo/swift-users<br class=""></div></blockquote></div><br class=""></div></body></html>