+/* Get the total number of messages in 'thread'.
+ *
+ * This count consists of all messages in the database belonging to
+ * this thread. Contrast with notmuch_thread_get_matched_messages() .
+ */
+int
+notmuch_thread_get_total_messages (notmuch_thread_t *thread);
+
+/* Get a notmuch_messages_t iterator for the top-level messages in
+ * 'thread'.
+ *
+ * This iterator will not necessarily iterate over all of the messages
+ * in the thread. It will only iterate over the messages in the thread
+ * which are not replies to other messages in the thread.
+ *
+ * To iterate over all messages in the thread, the caller will need to
+ * iterate over the result of notmuch_message_get_replies for each
+ * top-level message (and do that recursively for the resulting
+ * messages, etc.).
+ */
+notmuch_messages_t *
+notmuch_thread_get_toplevel_messages (notmuch_thread_t *thread);
+
+/* Get the number of messages in 'thread' that matched the search.
+ *
+ * This count includes only the messages in this thread that were
+ * matched by the search from which the thread was created. Contrast
+ * with notmuch_thread_get_total_messages() .
+ */
+int
+notmuch_thread_get_matched_messages (notmuch_thread_t *thread);
+