整理

include/boost/atomic/detail/aligned_variable.hpp

@@ -0,0 +1,57 @@
+/*
+ * 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)
+ *
+ * Copyright (c) 2020 Andrey Semashev
+ */
+/*!
+ * \file   atomic/detail/aligned_variable.hpp
+ *
+ * This header defines a convenience macro for declaring aligned variables
+ */
+
+#ifndef BOOST_ATOMIC_DETAIL_ALIGNED_VARIABLE_HPP_INCLUDED_
+#define BOOST_ATOMIC_DETAIL_ALIGNED_VARIABLE_HPP_INCLUDED_
+
+#include <boost/atomic/detail/config.hpp>
+#if defined(BOOST_ATOMIC_DETAIL_NO_CXX11_ALIGNAS)
+#include <boost/config/helper_macros.hpp>
+#include <boost/type_traits/type_with_alignment.hpp>
+#endif
+#include <boost/atomic/detail/header.hpp>
+
+#ifdef BOOST_HAS_PRAGMA_ONCE
+#pragma once
+#endif
+
+#if !defined(BOOST_ATOMIC_DETAIL_NO_CXX11_ALIGNAS)
+
+#define BOOST_ATOMIC_DETAIL_ALIGNED_VAR(var_alignment, var_type, var_name) \
+    alignas(var_alignment) var_type var_name
+
+#define BOOST_ATOMIC_DETAIL_ALIGNED_VAR_TPL(var_alignment, var_type, var_name) \
+    alignas(var_alignment) var_type var_name
+
+#else // !defined(BOOST_ATOMIC_DETAIL_NO_CXX11_ALIGNAS)
+
+// Note: Some compilers cannot use constant expressions in alignment attributes or alignas, so we have to use the union trick
+#define BOOST_ATOMIC_DETAIL_ALIGNED_VAR(var_alignment, var_type, var_name) \
+    union \
+    { \
+        var_type var_name; \
+        boost::type_with_alignment< var_alignment >::type BOOST_JOIN(var_name, _aligner); \
+    }
+
+#define BOOST_ATOMIC_DETAIL_ALIGNED_VAR_TPL(var_alignment, var_type, var_name) \
+    union \
+    { \
+        var_type var_name; \
+        typename boost::type_with_alignment< var_alignment >::type BOOST_JOIN(var_name, _aligner); \
+    }
+
+#endif // !defined(BOOST_ATOMIC_DETAIL_NO_CXX11_ALIGNAS)
+
+#include <boost/atomic/detail/footer.hpp>
+
+#endif // BOOST_ATOMIC_DETAIL_ALIGNED_VARIABLE_HPP_INCLUDED_