# File lib/structures.rb, line 54
    def diff(other, elements = self.class::ELEMENTS)
      diffs = {}

      elements.each do |element|
        if other.respond_to?(element)
          self_value = self.send(element)
          other_value = other.send(element)

          next if self_value == other_value

          diffs[element] = if other_value.respond_to?(:diff)
            self_value.diff(other_value)

          elsif other_value.is_a?(Enumerable) && other_value.all?{|v| v.respond_to?(:diff)}

            if self_value.size != other_value.size
              [self_value.size, other_value.size]
            else
              enum_diffs = []
              self_value.each_with_index do |val, index|
                enum_diffs << val.diff(other_value[index], val.class::ELEMENTS)
              end
              enum_diffs.reject{|h| h.empty?}
            end

          else
            [other_value, self_value] unless other_value == self_value
          end
        end
      end

      diffs
    end