UIViewController+SafeArea.swift

extension UIViewController {
    var safeTopAnchor: NSLayoutYAxisAnchor {
        if #available(iOS 11.0, *) {
            return view.safeAreaLayoutGuide.topAnchor
        } else {
            return topLayoutGuide.bottomAnchor
        }
    }
 
    var safeBottomAnchor: NSLayoutYAxisAnchor {
        if #available(iOS 11.0, *) {
            return view.safeAreaLayoutGuide.bottomAnchor
        } else {
            return bottomLayoutGuide.topAnchor
        }
    }
}