Guest user permissions with Rails and CanCan -

do need define permissions creating user guest? mean can sign out permissions?

this relative need, in cases not set specific permissions guest users. have @ how ryan bates suggest handeling cancan http://railscasts.com/episodes/192-authorization-with-cancan

in effect capture in initialisation of ability model:

  def initialize(user)     user ||= user.new # guest user      if user.role? :admin       #admin permissions     else       #default permissions     end   end