[swift-users] extension on UISlider breaks interface builder??

[David Baraff]

TL;DR
Add an extension to UISlider and interface builder in xcode will no longer believe it has *any* actions.
Is this a known issue?


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):



Next, I wrote this:

public protocol ModelDataValuedUIControl: class {
    var xxcontrolValue:Any {
        get set
    }
}

extension UISlider : ModelDataValuedUIControl {
    public var xxcontrolValue:Any {
        get {
            return self.value
        }
        
        set(newValue) {
            self.value = newValue as! Float
        }
    }
}


Lo and behold, after compiling, interface builder *hates* sliders, because now the rightclick menu looks like this:


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