From 2efcdccace7adf2a5e4fb5bf36607a7deab6ae0a Mon Sep 17 00:00:00 2001
From: Richard Newton <richard_newton@waters.com>
Date: Wed, 25 Jul 2012 12:20:27 +0100
Subject: [PATCH] Add const data access to message_t

Add a const version of data() and make size() const so we can pass messages around by
const refeference when we only need read-only data access.
---
 zmq.hpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/zmq.hpp b/zmq.hpp
index 041abb2..28ac046 100644
--- a/zmq.hpp
+++ b/zmq.hpp
@@ -179,9 +179,14 @@ namespace zmq
             return zmq_msg_data (&msg);
         }
 
-        inline size_t size ()
+        inline const void* data () const
         {
-            return zmq_msg_size (&msg);
+            return zmq_msg_data (const_cast<zmq_msg_t*>(&msg));
+        }
+
+        inline size_t size () const
+        {
+            return zmq_msg_size (const_cast<zmq_msg_t*>(&msg));
         }
 
     private: