UIBarButtonItem Closure UIButton example.swift

// Add to UIButton extension.
public func touchUpInside(closure: @escaping UIButtonTargetClosure) {
    targetClosure = closure
    addTarget(self, action: #selector(UIButton.closureAction), for: .touchUpInside)
}

// Useage
let button = UIButton()
button.touchUpInside { _ in
    // Do stuff.      
}