1 : // Move, forward and identity for C++0x + swap -*- C++ -*-
2 :
3 : // Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 : //
5 : // This file is part of the GNU ISO C++ Library. This library is free
6 : // software; you can redistribute it and/or modify it under the
7 : // terms of the GNU General Public License as published by the
8 : // Free Software Foundation; either version 3, or (at your option)
9 : // any later version.
10 :
11 : // This library is distributed in the hope that it will be useful,
12 : // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 : // GNU General Public License for more details.
15 :
16 : // Under Section 7 of GPL version 3, you are granted additional
17 : // permissions described in the GCC Runtime Library Exception, version
18 : // 3.1, as published by the Free Software Foundation.
19 :
20 : // You should have received a copy of the GNU General Public License and
21 : // a copy of the GCC Runtime Library Exception along with this program;
22 : // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 : // <http://www.gnu.org/licenses/>.
24 :
25 : /** @file bits/move.h
26 : * This is an internal header file, included by other library headers.
27 : * Do not attempt to use it directly. @headername{utility}
28 : */
29 :
30 : #ifndef _MOVE_H
31 : #define _MOVE_H 1
32 :
33 : #include <bits/c++config.h>
34 : #include <bits/concept_check.h>
35 :
36 : namespace std _GLIBCXX_VISIBILITY(default)
37 : {
38 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
39 :
40 : // Used, in C++03 mode too, by allocators, etc.
41 : template<typename _Tp>
42 : inline _Tp*
43 84010 : __addressof(_Tp& __r)
44 : {
45 : return reinterpret_cast<_Tp*>
46 84010 : (&const_cast<char&>(reinterpret_cast<const volatile char&>(__r)));
47 : }
48 :
49 : _GLIBCXX_END_NAMESPACE_VERSION
50 : } // namespace
51 :
52 : #ifdef __GXX_EXPERIMENTAL_CXX0X__
53 : #include <type_traits> // Brings in std::declval too.
54 :
55 : namespace std _GLIBCXX_VISIBILITY(default)
56 : {
57 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
58 :
59 : /// forward (as per N3143)
60 : template<typename _Tp>
61 : inline _Tp&&
62 : forward(typename std::remove_reference<_Tp>::type& __t)
63 : { return static_cast<_Tp&&>(__t); }
64 :
65 : template<typename _Tp>
66 : inline _Tp&&
67 : forward(typename std::remove_reference<_Tp>::type&& __t)
68 : {
69 : static_assert(!std::is_lvalue_reference<_Tp>::value, "template argument"
70 : " substituting _Tp is an lvalue reference type");
71 : return static_cast<_Tp&&>(__t);
72 : }
73 :
74 : /**
75 : * @brief Move a value.
76 : * @ingroup mutating_algorithms
77 : * @param __t A thing of arbitrary type.
78 : * @return Same, moved.
79 : */
80 : template<typename _Tp>
81 : inline typename std::remove_reference<_Tp>::type&&
82 : move(_Tp&& __t)
83 : { return static_cast<typename std::remove_reference<_Tp>::type&&>(__t); }
84 :
85 : /// declval, from type_traits.
86 :
87 : /**
88 : * @brief Returns the actual address of the object or function
89 : * referenced by r, even in the presence of an overloaded
90 : * operator&.
91 : * @param __r Reference to an object or function.
92 : * @return The actual address.
93 : */
94 : template<typename _Tp>
95 : inline _Tp*
96 : addressof(_Tp& __r)
97 : { return std::__addressof(__r); }
98 :
99 : _GLIBCXX_END_NAMESPACE_VERSION
100 : } // namespace
101 :
102 : #define _GLIBCXX_MOVE(__val) std::move(__val)
103 : #define _GLIBCXX_FORWARD(_Tp, __val) std::forward<_Tp>(__val)
104 : #else
105 : #define _GLIBCXX_MOVE(__val) (__val)
106 : #define _GLIBCXX_FORWARD(_Tp, __val) (__val)
107 : #endif
108 :
109 : namespace std _GLIBCXX_VISIBILITY(default)
110 : {
111 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
112 :
113 : /**
114 : * @brief Swaps two values.
115 : * @ingroup mutating_algorithms
116 : * @param __a A thing of arbitrary type.
117 : * @param __b Another thing of arbitrary type.
118 : * @return Nothing.
119 : */
120 : template<typename _Tp>
121 : inline void
122 : swap(_Tp& __a, _Tp& __b)
123 : {
124 : // concept requirements
125 : __glibcxx_function_requires(_SGIAssignableConcept<_Tp>)
126 :
127 : _Tp __tmp = _GLIBCXX_MOVE(__a);
128 : __a = _GLIBCXX_MOVE(__b);
129 : __b = _GLIBCXX_MOVE(__tmp);
130 : }
131 :
132 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
133 : // DR 809. std::swap should be overloaded for array types.
134 : template<typename _Tp, size_t _Nm>
135 : inline void
136 : swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
137 : {
138 : for (size_t __n = 0; __n < _Nm; ++__n)
139 : swap(__a[__n], __b[__n]);
140 : }
141 :
142 : _GLIBCXX_END_NAMESPACE_VERSION
143 : } // namespace
144 :
145 : #endif /* _MOVE_H */
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