<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=""><blockquote type="cite" class=""><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div class=""><div class="">raise an exception</div></div></div></blockquote><div class=""><br class=""></div>throw an error*<div class=""><br class=""></div><div class="">–</div><div class=""><br class=""></div><div class="">Or you could take advantage of powerful type system and error handling mechanisms and use neither `assert` nor `precondition`. Swift has so many features which ensure safety that using assertions is the last thing you could possibly lean towards – and I think that the flexibility to differentiate between `assert` and `precondition` is a precious choice to have, especially in high-performance code.</div><div class=""><br class=""></div><div class=""><div class="">
<div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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=""><font color="#929292" class=""><br class="Apple-interchange-newline">Pozdrawiam – Regards,</font></div><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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=""><font color="#929292" class="">Adrian Kashivskyy</font></div>
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<br class=""><div><blockquote type="cite" class=""><div class="">Wiadomość napisana przez Amir Michail <<a href="mailto:a.michail@me.com" class="">a.michail@me.com</a>> w dniu 09.12.2015, o godz. 01:00:</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=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Dec 8, 2015, at 6:59 PM, Adrian Kashivskyy <<a href="mailto:adrian.kashivskyy@me.com" class="">adrian.kashivskyy@me.com</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="">That's a choice I would have to carefully make when designing the behavior. Not all asserts are non-recoverable.<div class=""><br class=""></div></div></div></blockquote><div class=""><br class=""></div><div class="">You could have precondition raise an exception so you can catch it if you really want to.</div><br class=""><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><div class=""><div apple-content-edited="true" class=""><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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=""><font color="#929292" class="">Pozdrawiam – Regards,</font></div><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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=""><font color="#929292" class="">Adrian Kashivskyy</font></div>
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<br class=""><div class=""><blockquote type="cite" class=""><div class="">Wiadomość napisana przez Amir Michail <<a href="mailto:a.michail@me.com" class="">a.michail@me.com</a>> w dniu 09.12.2015, o godz. 00:56:</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=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Dec 8, 2015, at 6:55 PM, Adrian Kashivskyy <<a href="mailto:adrian.kashivskyy@me.com" class="">adrian.kashivskyy@me.com</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="">Strong -1, `assert` is a great tool for catching programmer errors in development phase, without compromising the stability in release mode.<br class=""></div></div></blockquote><div class=""><br class=""></div><div class="">You would rather have an ill-defined state rather than a crash with a useful bug report?</div><br class=""><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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=""><font color="#929292" class=""><br class="Apple-interchange-newline">Pozdrawiam – Regards,</font></div><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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=""><font color="#929292" class="">Adrian Kashivskyy</font></div>
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<br class=""><div class=""><blockquote type="cite" class=""><div class="">Wiadomość napisana przez Amir Michail via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> w dniu 09.12.2015, o godz. 00:52:</div><br class="Apple-interchange-newline"><div class=""><div class="">Swift is a safe language after all. Moreover, it is all too easy to accidentally type “assert” when you mean “precondition”.<br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></div></blockquote></div><br class=""></div></div></blockquote></div><br class=""></div></div></blockquote></div><br class=""></div></div></div></div></blockquote></div><br class=""></div></div></blockquote></div><br class=""></div></body></html>