I have a navigation controller as a root view to the home view then a sign in view then the main view. When I sign in and segue to the main view using
vc.performSegueWithIdentifier("toMenuView", sender: nil)
I can slide back to the sign in view. I don't want that. How can I segue to the main view without having access to going back unless the user taps the sign out button and then goes back to the home view without again having access to go "back" to the main view?