# File lib/cidr.rb, line 1978
    def to_s(options=nil)
        known_args = [:IP, :Short]
        short = false
        orig_ip = false

        if (options)
            if (!options.kind_of? Hash)
                raise ArgumentError, "Expected Hash, but #{options.class} provided."
            end
            NetAddr.validate_args(options.keys,known_args)

            if (options.has_key?(:Short) && options[:Short] == true)
                short = true
            end

            if (options.has_key?(:IP) && options[:IP] == true)
                orig_ip = true
            end
        end

        if (!orig_ip)
            ip = NetAddr.ip_int_to_str(@network, @version)
        else
            ip = NetAddr.ip_int_to_str(@ip, @version)
        end
        ip = NetAddr.shorten(ip) if (short && @version == 6)
        mask = NetAddr.mask_to_bits(@netmask)

        return("#{ip}/#{mask}")
    end