bool parse_url(const std::string &url, std::string *protocol, std::string *user, std::string *host, std::string *port, std::string *path);
// Figure out the right type of input based on the URL, and create a new Input of the right type.
-// Will return NULL if unknown.
+// Will return nullptr if unknown.
Input *create_input(const std::string &url, Input::Encoding encoding);
Input *create_input(const InputProto &serialized);