Internal state is not cloned

gistfile1.rb

class Obj
  attr_accessor :first, :second
  def initialize
    @first = {:one => 'x',:two => 'y',:three => 'z'}
    @second = {[1,2]=>'x',[3,2]=>'o'}
  end
end

# Using either dup or clone doesn't make a difference, they both make shallow copies
obj1 = Obj.new
obj2 = obj1.clone

# Different Objects in memory
obj1.object_id != obj2.object_id 

# Internal state is identical. Pointing to same objects in memory
obj1.first.object_id == obj2.first.object_id

# Hack to make a deep copy -- copy the entire internal state
obj3 = Marshal.load( Marshal.dump(obj1) )
obj3.first.object_id != obj1.first.object_id