controller_constraints

# File actionpack/lib/action_dispatch/routing/deprecated_mapper.rb, line 12
      def controller_constraints
        @controller_constraints ||= begin
          namespaces = controller_namespaces + in_memory_controller_namespaces
          source = namespaces.map { |ns| "#{Regexp.escape(ns)}/#{CONTROLLER_REGEXP.source}" }
          source << CONTROLLER_REGEXP.source
          Regexp.compile(source.sort.reverse.join('|'))
        end
      end