design-pattern.rb

require 'singleton'

class GlobalThingy
  include Singleton
end

GlobalThingy.instance
GlobalThingy.instance.object_id
GlobalThingy.new


require 'forwardable'

class Secretary
  def generate_report
    "data" * 10
  end
end

class Boss
  extend Forwardable
  def_delegator :@secretary, :generate_report
  
  def initialize(secretary)
    @secretary = secretary
  end
end