Ruby yield - SaaS Course - Home Work 01, part 6 a.

class CartesianProduct
  include Enumerable
  @@p
  def initialize(arg1, arg2)
    @@p = arg1.product arg2
  end
  def each
    @@p.each do |elt| yield elt end
  end
end
#Examples of use
c = CartesianProduct.new([:a,:b], [4,5])
c.each { |elt| puts elt.inspect }
# [:a, 4]
# [:a, 5]
# [:b, 4]
# [:b, 5]
c = CartesianProduct.new([:a,:b], [])
c.each { |elt| puts elt.inspect }
# (nothing printed since Cartesian product
# of anything with an empty collection is empty)