<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=""><div class="">BTW, structures are immutable yet they can have mutating functions.</div><div class=""><br class=""></div><div class="">I fully understand how this works as a language user but I wonder...</div><div class=""><br class=""></div><div class="">Isn’t there a better keyword (than “mutating”) that we could use here?</div><div class=""><br class=""></div><div class="">R+</div><div class=""><br class=""></div><div><blockquote type="cite" class=""><div class="">On 23 Dec 2015, at 16:51, Ian Ynda-Hummel 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: 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 thought structures were immutable and mutating functions actually just created new structures, thus maintaining the by value semantics.</span><br 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;" class=""><div class="gmail_quote" 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;"><div dir="ltr" class="">On Wed, Dec 23, 2015 at 10:45 AM Lino Rosa via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin: 0px 0px 0px 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex;"><div dir="ltr" class=""><div class="">I believe the language would be improved by making structures immutable.</div><div class=""><br class=""></div><div class="">1) The choice between classes and structures isn’t clear right now. If structures were immutable it would be natural to use them as value objects.</div><div class=""><br class=""></div><div class="">2) Refactoring a mutable structure into a class when it’s being passed around multiple threads removes the by-value semantics seamlessly. The resulting mutable class isn’t thread-safe.</div><div class=""><br class=""></div><div class="">2.1) Even when passed around a single thread, the resulting class would be passed by reference, so any mutations would have unintended consequences.</div><div class=""><br class=""></div><div class="">3) We could probably remove some syntax: `mutating` keyword and variable parameters. Also the `var` keyword before a structure could be used to denote reassignment (not mutability), just as it does with classes.</div><div class=""><br class=""></div><div class="">Of corse I might not be seeing the whole picture, so please weigh in.</div></div><img src="https://u2002410.ct.sendgrid.net/wf/open?upn=t5fkNsX-2F7-2FAygTFNPNE08PALgkjkO6I8wpsdssDS0uhzD3EyON0qfaM-2BbDYaPGa4azavBvUgXrcfIjbzgpxE8eP9166AITzK3ots1xL7ZbX7ZYqgZjOge2IKsot-2FFjNUORr0LjCExRUPumI8I-2BZoBO7yyqFqYpqCAk5TqOB5aWgB9OMHq0v4txo-2BHeGuoLN9wTozGfCQnGAys309-2B-2Biow4Vc-2FxAZMKOilKYVoGIgGMI-3D" alt="" width="1" height="1" border="0" style="min-height: 1px !important; width: 1px !important; border-width: 0px !important; margin: 0px !important; padding: 0px !important;" class=""><span class="Apple-converted-space"> </span>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" rel="noreferrer" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></blockquote></div><img src="https://u2002410.ct.sendgrid.net/wf/open?upn=j4IybsUIPYHiRcwUyRdFaSyY9hW0Q-2F-2F4mkUT8Mp-2BrkVESLQwRlNxbx0TNVmf1KtmO3921GhChe7yAr1s2VpFhIVIek0y90j08-2BqRNTpJzzJQX80eZ4IcU-2BU23AWmp8xa5PZtehTPb-2B55rf1VxMEquFir65smZJtQja0-2FUd87ZVqf0jCR8jj-2BGbDGZtfPvKKOQetY5lUzLTHCJ6saEyUPBg-3D-3D" alt="" width="1" height="1" border="0" 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; height: 1px !important; width: 1px !important; border-width: 0px !important; margin: 0px !important; padding: 0px !important;" class=""><span 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; float: none; display: inline !important;" class=""><span class="Apple-converted-space"> </span>_______________________________________________</span><br 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;" class=""><span 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; float: none; display: inline !important;" class="">swift-evolution mailing list</span><br 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;" class=""><a href="mailto:swift-evolution@swift.org" 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;" class="">swift-evolution@swift.org</a><br 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;" class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" 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;" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a></div></blockquote></div><br class=""></body></html>