advishnuprasad/meta_programming.rb

## meta_programming.rb
o = Object.new

# class_eval example
class << o; self; end.class_eval { def test1;  :test1; end  }
o.test1 #=> test1

# instance_eval example
class << o; self; end.instance_eval { def test2; :test2; end }
o.test2 #=> NoMethodError
	o = Object.new

	# class_eval example
	class << o; self; end.class_eval { def test1; :test1; end }
	o.test1 #=> test1

	# instance_eval example
	class << o; self; end.instance_eval { def test2; :test2; end }
	o.test2 #=> NoMethodError