<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">TL;DR</div><div class="">Add an extension to UISlider and interface builder in xcode will no longer believe it has *any* actions.</div><div class="">Is this a known issue?</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">1. I added a UISlider to a storyboard in xcode. I right clicked on it, and saw the usual set of things, particularly, actions (sent events):</div><div class=""><br class=""></div><div class=""><img apple-inline="yes" id="6725F296-6E88-4E2C-80C8-5264172A2403" src="cid:0F58AD8A-6CB5-4C85-B00D-CD97F066A8B6@pixar.com" class=""></div><div class=""><br class=""></div><div class="">Next, I wrote this:</div><div class=""><br class=""></div>public protocol ModelDataValuedUIControl: class {<br class=""> var xxcontrolValue:Any {<br class=""> get set<br class=""> }<br class="">}<br class=""><br class="">extension UISlider : ModelDataValuedUIControl {<br class=""> public var xxcontrolValue:Any {<br class=""> get {<br class=""> return self.value<br class=""> }<br class=""> <br class=""> set(newValue) {<br class=""> self.value = newValue as! Float<br class=""> }<br class=""> }<br class="">}<br class=""><br class=""><div class=""><br class=""></div><div class="">Lo and behold, after compiling, interface builder *hates* sliders, because now the rightclick menu looks like this:</div><div class=""><img apple-inline="yes" id="AFE9BA25-6331-4AC5-901E-30C46F5ECE2D" src="cid:0A01089F-1EB4-4EBE-AE06-46B30AA7F4D7@pixar.com" class=""></div><div class=""><br class=""></div></body></html>