Multiple routes in Rails 4- Different homepage views for signed in users vs new visitors

Rails 4 does not allow you to create 2 roots in your routes file, unless you modify one of them as authenticated. I have included a simple example below as extracted from the Mackenzie Child Notebook application. Sytax is in italics :

​Rails.application.routes.draw do
  devise_for :users
  get 'welcome/index'
  resources :notes

  authenticated :user do
      root 'notes#index', as: "authenticated_root"
  end


  root 'welcome#index'
  
end