]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | //----------------------------------------------------------------------------- |
2 | // boost aligned_storage.hpp header file | |
3 | // See http://www.boost.org for updates, documentation, and revision history. | |
4 | //----------------------------------------------------------------------------- | |
5 | // | |
6 | // Copyright (c) 2002-2003 | |
7 | // Eric Friedman, Itay Maman | |
8 | // | |
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) | |
12 | ||
13 | #ifndef BOOST_TT_ALIGNED_STORAGE_HPP | |
14 | #define BOOST_TT_ALIGNED_STORAGE_HPP | |
15 | ||
16 | #include <cstddef> // for std::size_t | |
17 | ||
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> | |
23 | #include <boost/type_traits/conditional.hpp> | |
24 | ||
25 | namespace boost { | |
26 | ||
27 | namespace detail { namespace aligned_storage { | |
28 | ||
29 | BOOST_STATIC_CONSTANT( | |
30 | std::size_t | |
31 | , alignment_of_max_align = ::boost::alignment_of<boost::detail::max_align>::value | |
32 | ); | |
33 | ||
34 | // | |
35 | // To be TR1 conforming this must be a POD type: | |
36 | // | |
37 | template < | |
38 | std::size_t size_ | |
39 | , std::size_t alignment_ | |
40 | > | |
41 | struct aligned_storage_imp | |
42 | { | |
43 | union data_t | |
44 | { | |
45 | char buf[size_]; | |
46 | ||
47 | typename ::boost::type_with_alignment<alignment_>::type align_; | |
48 | } data_; | |
49 | void* address() const { return const_cast<aligned_storage_imp*>(this); } | |
50 | }; | |
51 | template <std::size_t size> | |
52 | struct aligned_storage_imp<size, std::size_t(-1)> | |
53 | { | |
54 | union data_t | |
55 | { | |
56 | char buf[size]; | |
57 | ::boost::detail::max_align align_; | |
58 | } data_; | |
59 | void* address() const { return const_cast<aligned_storage_imp*>(this); } | |
60 | }; | |
61 | ||
62 | template< std::size_t alignment_ > | |
63 | struct aligned_storage_imp<0u,alignment_> | |
64 | { | |
65 | /* intentionally empty */ | |
66 | void* address() const { return 0; } | |
67 | }; | |
68 | ||
69 | }} // namespace detail::aligned_storage | |
70 | ||
71 | template < | |
72 | std::size_t size_ | |
73 | , std::size_t alignment_ = std::size_t(-1) | |
74 | > | |
75 | class aligned_storage : | |
76 | #ifndef __BORLANDC__ | |
77 | private | |
78 | #else | |
79 | public | |
80 | #endif | |
81 | ::boost::detail::aligned_storage::aligned_storage_imp<size_, alignment_> | |
82 | { | |
83 | ||
84 | public: // constants | |
85 | ||
86 | typedef ::boost::detail::aligned_storage::aligned_storage_imp<size_, alignment_> type; | |
87 | ||
88 | BOOST_STATIC_CONSTANT( | |
89 | std::size_t | |
90 | , size = size_ | |
91 | ); | |
92 | BOOST_STATIC_CONSTANT( | |
93 | std::size_t | |
94 | , alignment = ( | |
95 | alignment_ == std::size_t(-1) | |
96 | ? ::boost::detail::aligned_storage::alignment_of_max_align | |
97 | : alignment_ | |
98 | ) | |
99 | ); | |
100 | ||
101 | private: // noncopyable | |
102 | ||
103 | aligned_storage(const aligned_storage&); | |
104 | aligned_storage& operator=(const aligned_storage&); | |
105 | ||
106 | public: // structors | |
107 | ||
108 | aligned_storage() | |
109 | { | |
110 | } | |
111 | ||
112 | ~aligned_storage() | |
113 | { | |
114 | } | |
115 | ||
116 | public: // accessors | |
117 | ||
118 | void* address() | |
119 | { | |
120 | return static_cast<type*>(this)->address(); | |
121 | } | |
122 | ||
123 | const void* address() const | |
124 | { | |
125 | return static_cast<const type*>(this)->address(); | |
126 | } | |
127 | }; | |
128 | ||
129 | // | |
130 | // Make sure that is_pod recognises aligned_storage<>::type | |
131 | // as a POD (Note that aligned_storage<> itself is not a POD): | |
132 | // | |
133 | template <std::size_t size_, std::size_t alignment_> | |
134 | struct is_pod< ::boost::detail::aligned_storage::aligned_storage_imp<size_, alignment_> > : public true_type{}; | |
135 | ||
136 | } // namespace boost | |
137 | ||
138 | #endif // BOOST_ALIGNED_STORAGE_HPP |