ArrayLike object in Ruby 1.9.

arraylike.rb

class ArrayLike
  include Enumerable

  def initialize(arr)
    @arr = arr
  end

  def count
    @arr.count
  end

  def each
    @arr.each do |value|
      yield value
    end
  end

  def [](key)
    @arr[key]
  end

  def []=(key, value)
    @arr[key] = value
  end
end

example.rb

require_relative 'arraylike'

arr_obj = ArrayLike.new ['foo', 'bar', 'baz']

puts arr_obj.count

arr_obj.each_with_index do |value, key|
  puts "#{key}:#{value}"
end

arr_obj[1] = 'hoge'
puts arr_obj[1]