+ * attempting to read the next event, in which case the connection is
+ * shut down when this function returns.
+ */
+xcb_generic_event_t *xcb_poll_for_event(xcb_connection_t *c);
+
+/**
+ * @brief Returns the next event without reading from the connection.
+ * @param c: The connection to the X server.
+ * @return The next already queued event from the server.
+ *
+ * This is a version of xcb_poll_for_event that only examines the
+ * event queue for new events. The function doesn't try to read new
+ * events from the connection if no queued events are found.
+ *
+ * This function is useful for callers that know in advance that all
+ * interesting events have already been read from the connection. For
+ * example, callers might use xcb_wait_for_reply and be interested
+ * only of events that preceded a specific reply.
+ */
+xcb_generic_event_t *xcb_poll_for_queued_event(xcb_connection_t *c);
+
+/**
+ * @brief Return the error for a request, or NULL if none can ever arrive.
+ * @param c: The connection to the X server.
+ * @param cookie: The request cookie.
+ * @return The error for the request, or NULL if none can ever arrive.
+ *
+ * The xcb_void_cookie_t cookie supplied to this function must have resulted
+ * from a call to xcb_[request_name]_checked(). This function will block
+ * until one of two conditions happens. If an error is received, it will be
+ * returned. If a reply to a subsequent request has already arrived, no error
+ * can arrive for this request, so this function will return NULL.
+ *
+ * Note that this function will perform a sync if needed to ensure that the
+ * sequence number will advance beyond that provided in cookie; this is a
+ * convenience to avoid races in determining whether the sync is needed.