diff -r 98dc2d3a9b1d -r db732f8c083a ucx/avl.h
--- a/ucx/avl.h	Sat Jul 15 20:46:18 2017 +0200
+++ b/ucx/avl.h	Sat Jul 15 22:36:29 2017 +0200
@@ -303,6 +303,22 @@
  */
 size_t ucx_avl_count(UcxAVLTree *tree);
 
+/**
+ * Finds the in-order predecessor of the given node.
+ * @param node an AVL node
+ * @return the in-order predecessor of the given node, or <code>NULL</code> if
+ * the given node is the in-order minimum
+ */
+UcxAVLNode* ucx_avl_pred(UcxAVLNode* node);
+
+/**
+ * Finds the in-order successor of the given node.
+ * @param node an AVL node
+ * @return the in-order successor of the given node, or <code>NULL</code> if
+ * the given node is the in-order maximum
+ */
+UcxAVLNode* ucx_avl_succ(UcxAVLNode* node);
+
 #ifdef	__cplusplus
 }
 #endif