enumerable_method.rb

class Object
  def self.enumerable *meths
    meths.each do |meth|
      alias_method "#{meth}_without_enumerator", meth
      class_eval %{
        def #{meth}(*args, &block)
          return Enumerable::Enumerator.new(self, #{meth.inspect}, *args, &block) unless block_given?
          #{meth}_without_enumerator(*args, &block)
        end
      }
    end
  end
end


class Blah

  def stuff(&block)
    10.times { |x| yield x }
  end

  enumerable :stuff

end

p Blah.new.stuff
p Blah.new.stuff.to_a