I have a problem when dragging a navigation bar or toolbar (storyboard) to my view controller.
UINavigationBar:
I gave up and had to set the navbar height constraint to 64 in x xib based VC cause viewController.topLayoutGuide.length is 0 in viewDidLoad despite statusbar being present :-[ which means in a non universal app on ipad you'd have 20 px on the top of the view wasted (cause status bar is separate from the iphone simulation window)