From bddb28941a9982dd115227b540ec9dbd13d43380 Mon Sep 17 00:00:00 2001
From: Patrick Pelissier <patrick.pelissier@gmail.com>
Date: Mon, 20 Feb 2017 22:48:36 +0100
Subject: [PATCH] Update doc

---
 README.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/README.md b/README.md
index 52a296af..aaa57769 100644
--- a/README.md
+++ b/README.md
@@ -1078,6 +1078,10 @@ It shall not be confused with a B-TREE.
 
 The CMP operator is used to perform the total ordering of the elements.
 
+The UPDATE operator is used to update an element if the 
+pushed item already exist in the container. The default behavior
+will overwrite the recorded value with the new one.
+ 
 It shall be done once per type and per compilation unit.
 It also define the iterator rbtree\_it\_##name##\_t and its associated methods as "static inline" functions.