<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">+1 for toggle, seems the clear winner for me.<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Jan 12, 2018, at 8:29 AM, Cheyo Jimenez 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 style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">It’s a slippery slope because it makes me want to have something like `not()` added to the library. I don’t think it’s worth it. </div><br class="Apple-interchange-newline"></div></blockquote></div><br class=""><div class="">I would love to have not(), but for a different purpose:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-stretch: normal; font-size: 13px; line-height: normal; font-family: Menlo; background-color: rgb(255, 255, 255);" class=""><span style="color: #ba2da2" class="">func</span> not<T>(<span style="color: #ba2da2" class="">_</span> predicate: <span style="color: #ba2da2" class="">@escaping</span> (<span style="color: #4f8187" class="">T</span>)-><span style="color: #703daa" class="">Bool</span>) -> (<span style="color: #4f8187" class="">T</span>)-><span style="color: #703daa" class="">Bool</span> {</div><div style="margin: 0px; font-stretch: normal; font-size: 13px; line-height: normal; font-family: Menlo; background-color: rgb(255, 255, 255);" class=""> <span style="color: #ba2da2" class="">return</span> { !predicate($0) }</div><div style="margin: 0px; font-stretch: normal; font-size: 13px; line-height: normal; font-family: Menlo; background-color: rgb(255, 255, 255);" class="">}</div><div style="margin: 0px; font-stretch: normal; line-height: normal; background-color: rgb(255, 255, 255); min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; font-size: 13px; line-height: normal; font-family: Menlo; background-color: rgb(255, 255, 255);" class=""><span style="color: #ba2da2" class="">let</span> noScrubs = <span style="color: #4f8187" class="">guys</span>.<span style="color: #3e1e81" class="">filter</span>(<span style="color: #31595d" class="">not</span>(<span style="color: #4f8187" class="">isBusta</span>))</div></div><div class=""><br class=""></div><div class="">I guess you could overload a version of ! for predicates but that doesn’t seem wise.</div><div class=""><br class=""></div><div class=""><br class=""></div></body></html>