guard_conditions

# File actionpack/lib/action_controller/routing/optimisations.rb, line 67
        def guard_conditions
          number_of_arguments = route.required_segment_keys.size
          # if they're using foo_url(:id=>2) it's one
          # argument, but we don't want to generate /foos/id2
          if number_of_arguments == 1
            ["args.size == 1", "!args.first.is_a?(Hash)"]
          else
            ["args.size == #{number_of_arguments}"]
          end
        end