<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="">Hi,<div class=""><br class=""></div><div class="">I defined this:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #ba2da2" class="">func</span><span style="font-variant-ligatures: no-common-ligatures" class=""> random(from r: </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Range</span><span style="font-variant-ligatures: no-common-ligatures" class=""><</span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class="">>) -> </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class=""> {</span></div><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #ba2da2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> from = r.</span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">lowerBound</span></div><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #ba2da2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> to = r.</span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">upperBound</span></div><p style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo; min-height: 16px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><br class="webkit-block-placeholder"></p><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #ba2da2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> rnd = </span><span style="font-variant-ligatures: no-common-ligatures; color: #3e1e81" class="">arc4random_uniform</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">UInt32</span><span style="font-variant-ligatures: no-common-ligatures" class="">(to-from))</span></div><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #ba2da2" class="">return</span><span style="font-variant-ligatures: no-common-ligatures" class=""> from + </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class="">(rnd)</span></div><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">}</span></div></div><div class=""><br class=""></div><div class="">so that I can do:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #ba2da2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> testRandomValue = </span><span style="font-variant-ligatures: no-common-ligatures; color: #31595d" class="">random</span><span style="font-variant-ligatures: no-common-ligatures" class="">(from: </span><span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">4</span><span style="font-variant-ligatures: no-common-ligatures" class="">..<</span><span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">8</span><span style="font-variant-ligatures: no-common-ligatures" class="">)</span></div></div><div class=""><br class=""></div><div class="">But this will not let me do:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #ba2da2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> otherTestRandomValue = random(from: </span><span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">4</span><span style="font-variant-ligatures: no-common-ligatures" class="">...</span><span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">10</span><span style="font-variant-ligatures: no-common-ligatures" class="">)</span></div></div><div class=""><br class=""></div><div class="">The error message is a bit cryptic:</div><div class=""><br class=""></div><div class="">“No ‘…’ candidate produce the expected contextual result type ‘Range<Int>’”</div><div class=""><br class=""></div><div class="">What is happening is that 4…10 is not a Range, but a ClosedRange.</div><div class=""><br class=""></div><div class="">Of course I can overload my function above to add a version that takes a ClosedRange.</div><div class=""><br class=""></div><div class="">But this is not very DRY.</div><div class=""><br class=""></div><div class="">What would be a more idiomatic way?</div><div class=""><br class=""></div><div class="">Thanks,</div><div class=""><br class=""></div><div class="">Jean-Denis</div><div class=""><br class=""></div></body></html>