class.rb

module Inventoryable

  module ClassMethods
    
    def create(attributes)
      object = new(attributes)
      instances << object
      object
    end

    def instances
      @instances ||= []  ## in this case its instance CLASS variable !?
    end

  end

  def stock_count
    @stock_count ||= 0
  end

  def stock_count=(number)
    @stock_count = number
  end

  def in_stock?
    @stock_count > 0 ? true : false
  end

end


class Shirt
  extend Inventoryable::ClassMethods
  include Inventoryable
  attr_accessor :attributes

  def initialize(attributes)
    @attributes = attributes
  end

  def instances
    puts @instances
  end
end 

class Pant
  include Inventoryable
  attr_accessor :attributes

  def initialize(attributes)
    @attributes = attributes
    @stock_count += 1
  end
end 

class Accessory
  include Inventoryable
  attr_accessor :attributes

  def initialize(attributes)
    @attributes = attributes
    @stock_count += 1
  end
end 


shirt1 = Shirt.create(name: "Vans", size: "L")
shirt2 = Shirt.create(name: "Vans", size: "XL")
shirt1.stock_count = 40


puts Shirt.instances # each created object stored in instacne class variable? @instances?
puts "!!! #{shirt1.instances}" #can't access to instance class variable