From 52b0f65bb32dbf05c03f401de4aa66a91aee0f73 Mon Sep 17 00:00:00 2001
From: Vinnie Falco <vinnie.falco@gmail.com>
Date: Fri, 16 Aug 2013 05:59:32 -0700
Subject: [PATCH] Check for macro before setting it

---
 modules/beast_asio/system/beast_BoostIncludes.h | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/modules/beast_asio/system/beast_BoostIncludes.h b/modules/beast_asio/system/beast_BoostIncludes.h
index 917139a7d..a3a48406f 100644
--- a/modules/beast_asio/system/beast_BoostIncludes.h
+++ b/modules/beast_asio/system/beast_BoostIncludes.h
@@ -50,12 +50,16 @@
 // Configure some options based on the version of boost
 #include <boost/version.hpp>
 #if (BOOST_VERSION / 100) >= 1054
-# define BEAST_ASIO_HAS_BUFFEREDHANDSHAKE 1
+# ifndef BEAST_ASIO_HAS_BUFFEREDHANDSHAKE
+#  define BEAST_ASIO_HAS_BUFFEREDHANDSHAKE 1
+# endif
 # ifndef BEAST_ASIO_HAS_FUTURE_RETURNS
 #  define BEAST_ASIO_HAS_FUTURE_RETURNS 1
 # endif
 #else
-# define BEAST_ASIO_HAS_BUFFEREDHANDSHAKE 0
+# ifndef BEAST_ASIO_HAS_BUFFEREDHANDSHAKE
+#  define BEAST_ASIO_HAS_BUFFEREDHANDSHAKE 0
+# endif
 # ifndef BEAST_ASIO_HAS_FUTURE_RETURNS
 #  define BEAST_ASIO_HAS_FUTURE_RETURNS 0
 # endif