1 //-----------------------------------------------------------------------------
2 // boost aligned_storage.hpp header file
3 // See http://www.boost.org for updates, documentation, and revision history.
4 //-----------------------------------------------------------------------------
6 // Copyright (c) 2002-2003
7 // Eric Friedman, Itay Maman
9 // Distributed under the Boost Software License, Version 1.0. (See
10 // accompanying file LICENSE_1_0.txt or copy at
11 // http://www.boost.org/LICENSE_1_0.txt)
13 #ifndef BOOST_ALIGNED_STORAGE_HPP
14 #define BOOST_ALIGNED_STORAGE_HPP
16 #include <cstddef> // for std::size_t
18 #include "boost/config.hpp"
19 #include "boost/detail/workaround.hpp"
20 #include "boost/type_traits/alignment_of.hpp"
21 #include "boost/type_traits/type_with_alignment.hpp"
22 #include "boost/type_traits/is_pod.hpp"
24 #include "boost/mpl/eval_if.hpp"
25 #include "boost/mpl/identity.hpp"
27 #include "boost/type_traits/detail/bool_trait_def.hpp"
31 namespace detail { namespace aligned_storage {
33 BOOST_STATIC_CONSTANT(
35 , alignment_of_max_align = ::boost::alignment_of<max_align>::value
39 // To be TR1 conforming this must be a POD type:
43 , std::size_t alignment_
45 struct aligned_storage_imp
51 typename mpl::eval_if_c<
52 alignment_ == std::size_t(-1)
53 , mpl::identity<detail::max_align>
54 , type_with_alignment<alignment_>
57 void* address() const { return const_cast<aligned_storage_imp*>(this); }
60 template< std::size_t alignment_ >
61 struct aligned_storage_imp<0u,alignment_>
63 /* intentionally empty */
64 void* address() const { return 0; }
67 }} // namespace detail::aligned_storage
71 , std::size_t alignment_ = std::size_t(-1)
73 class aligned_storage :
79 detail::aligned_storage::aligned_storage_imp<size_, alignment_>
84 typedef detail::aligned_storage::aligned_storage_imp<size_, alignment_> type;
86 BOOST_STATIC_CONSTANT(
90 BOOST_STATIC_CONSTANT(
93 alignment_ == std::size_t(-1)
94 ? ::boost::detail::aligned_storage::alignment_of_max_align
99 #if defined(__GNUC__) &&\
101 (__GNUC__ == 3 && (__GNUC_MINOR__ > 2 ||\
102 (__GNUC_MINOR__ == 2 && __GNUC_PATCHLEVEL__ >=3)))
104 private: // noncopyable
106 aligned_storage(const aligned_storage&);
107 aligned_storage& operator=(const aligned_storage&);
109 #else // gcc less than 3.2.3
111 public: // _should_ be noncopyable, but GCC compiler emits error
113 aligned_storage(const aligned_storage&);
114 aligned_storage& operator=(const aligned_storage&);
116 #endif // gcc < 3.2.3 workaround
132 return static_cast<type*>(this)->address();
135 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
137 const void* address() const
139 return static_cast<const type*>(this)->address();
144 const void* address() const;
146 #endif // MSVC6 workaround
150 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
152 // MSVC6 seems not to like inline functions with const void* returns, so we
153 // declare the following here:
155 template <std::size_t S, std::size_t A>
156 const void* aligned_storage<S,A>::address() const
158 return const_cast< aligned_storage<S,A>* >(this)->address();
161 #endif // MSVC6 workaround
163 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
165 // Make sure that is_pod recognises aligned_storage<>::type
166 // as a POD (Note that aligned_storage<> itself is not a POD):
168 template <std::size_t size_, std::size_t alignment_>
169 struct is_pod<boost::detail::aligned_storage::aligned_storage_imp<size_,alignment_> >
170 BOOST_TT_AUX_BOOL_C_BASE(true)
172 BOOST_TT_AUX_BOOL_TRAIT_VALUE_DECL(true)
179 #include "boost/type_traits/detail/bool_trait_undef.hpp"
181 #endif // BOOST_ALIGNED_STORAGE_HPP