Why these warnings?

  $ cat t.rb

  @c = Class.new do
    def initialize
      @@xx = 10
    end
    def xx?; @@xx; end
  end

  c = @c.new
  c.xx?

  $ ruby t.rb
  t.rb:3: warning: class variable access from toplevel
  t.rb:5: warning: class variable access from toplevel