Add launcer helper

include/boost/move/detail/launder.hpp

@@ -0,0 +1,53 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2014-2015. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/container for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+#ifndef BOOST_MOVE_DETAIL_LAUNDER_HPP
+#define BOOST_MOVE_DETAIL_LAUNDER_HPP
+
+#ifndef BOOST_CONFIG_HPP
+#  include <boost/config.hpp>
+#endif
+
+#if defined(BOOST_HAS_PRAGMA_ONCE)
+#  pragma once
+#endif
+
+#include <boost/move/detail/workaround.hpp>
+
+namespace boost {
+namespace move_detail {
+
+#if defined(BOOST_MOVE_HAS_BUILTIN_LAUNDER)
+
+template<class T>
+BOOST_MOVE_FORCEINLINE T* launder(T* p)
+{
+    return __builtin_launder( p );
+}
+
+#else
+
+template<class T>
+BOOST_MOVE_FORCEINLINE T* launder(T* p)
+{
+    return p;
+}
+
+#endif
+
+template<class T>
+BOOST_MOVE_FORCEINLINE T launder_cast(const volatile void* p)
+{
+   return (launder)((T)p);
+}
+
+}  //namespace move_detail {
+}  //namespace boost {
+
+#endif   //#ifndef BOOST_MOVE_DETAIL_LAUNDER_HPP

include/boost/move/detail/workaround.hpp

@@ -147,5 +147,10 @@ template<unsigned> struct static_assert_test {};
 #define BOOST_MOVE_INTRINSIC_CAST BOOST_MOVE_FORCEINLINE
 #endif
 
-#endif   //#ifndef BOOST_MOVE_DETAIL_WORKAROUND_HPP
+#if defined(__has_builtin)
+#if __has_builtin(__builtin_launder)
+   #define BOOST_MOVE_HAS_BUILTIN_LAUNDER
+#endif
+#endif
 
+#endif   //#ifndef BOOST_MOVE_DETAIL_WORKAROUND_HPP