From fbb851097fa800fa9f19d6936906af7777d90215 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Sat, 1 Mar 2014 02:14:56 +0200
Subject: [PATCH] Disable the std::atomic spinlock implementation on Clang

---
 include/boost/smart_ptr/detail/spinlock.hpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/boost/smart_ptr/detail/spinlock.hpp b/include/boost/smart_ptr/detail/spinlock.hpp
index deffb67..19f93d7 100644
--- a/include/boost/smart_ptr/detail/spinlock.hpp
+++ b/include/boost/smart_ptr/detail/spinlock.hpp
@@ -32,7 +32,13 @@
 #include <boost/smart_ptr/detail/sp_has_sync.hpp>
 
 #if defined( BOOST_SP_USE_STD_ATOMIC )
-# include <boost/smart_ptr/detail/spinlock_std_atomic.hpp>
+# if !defined( __clang__ )
+#   include <boost/smart_ptr/detail/spinlock_std_atomic.hpp>
+# else
+//  Clang (at least up to 3.4) can't compile spinlock_pool when
+//  using std::atomic, so substitute the __sync implementation instead.
+#   include <boost/smart_ptr/detail/spinlock_sync.hpp>
+# endif
 
 #elif defined( BOOST_SP_USE_PTHREADS )
 #  include <boost/smart_ptr/detail/spinlock_pt.hpp>