The multiclosures get released before "event" returns; I need to figure out why, or another method to keep them around.

UIControl+EventDispatcher.swift

extension UIControl {
    override public func didMoveToSuperview()
    {
        super.didMoveToSuperview()
        alterControlEventsAssignment(addTarget)
    }
    
    override public func removeFromSuperview()
    {
        super.removeFromSuperview()
        alterControlEventsAssignment(removeTarget)
    }
    
    static let controlEvents = [
        HandlerSelector.onDidTouchDown.rawValue: UIControlEvents.TouchDown,
        HandlerSelector.onValueChanged.rawValue: UIControlEvents.ValueChanged
    ]
    
    private func alterControlEventsAssignment(
        assign: (
            target: AnyObject?,
            action: Selector,
            forControlEvents: UIControlEvents
        ) -> ()
    ) {
        UIControl.controlEvents.forEach {assign(
            target: self,
            action: $0.0,
            forControlEvents: $0.1
        )}
    }
    
    private func event(inout 😾events: [UIControl: MultiClosure<(), ()>])
    -> MultiClosure<(), ()> {
        if let event = 😾events[self] {return event}
        😾events[self] = MultiClosure<(), ()>()
        return 😾events[self]!
    }
    
    var didTouchDown: MultiClosure<(), ()> {return event(&😾didTouchDown)}
    var valueChanged: MultiClosure<(), ()> {return event(&😾valueChanged)}
    
    func onDidTouchDown() {didTouchDown.run()}
    func onValueChanged() {valueChanged.run()}
}

private var
    😾didTouchDown = [UIControl: MultiClosure<(), ()>](),
    😾valueChanged = [UIControl: MultiClosure<(), ()>]()

private extension UIControl {enum HandlerSelector: Selector {
    case onDidTouchDown, onValueChanged
}}