require 'facet/enumerable/cross'
module Enumerable
  # Operator alias for cross-product.
  #
  #   require 'facet/enumerable/cross'
  #
  #   a = [1,2] ** [4,5]
  #   a  #=> [[1, 4],[1, 5],[2, 4],[2, 5]]
  #
  def **(enum)
    Enumerable.cross(self, enum)
  end
end