1 // Move, forward and identity for C++0x + swap -*- C++ -*-
3 // Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
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)
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.
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.
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/>.
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{utility}
33 #include <bits/c++config.h>
34 #include <bits/concept_check.h>
36 namespace std _GLIBCXX_VISIBILITY(default)
38 _GLIBCXX_BEGIN_NAMESPACE_VERSION
40 // Used, in C++03 mode too, by allocators, etc.
41 template<typename _Tp>
45 return reinterpret_cast<_Tp*>
46 (&const_cast<char&>(reinterpret_cast<const volatile char&>(__r)));
49 _GLIBCXX_END_NAMESPACE_VERSION
52 #ifdef __GXX_EXPERIMENTAL_CXX0X__
53 #include <type_traits> // Brings in std::declval too.
55 namespace std _GLIBCXX_VISIBILITY(default)
57 _GLIBCXX_BEGIN_NAMESPACE_VERSION
59 /// forward (as per N3143)
60 template<typename _Tp>
62 forward(typename std::remove_reference<_Tp>::type& __t)
63 { return static_cast<_Tp&&>(__t); }
65 template<typename _Tp>
67 forward(typename std::remove_reference<_Tp>::type&& __t)
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);
75 * @brief Move a value.
76 * @ingroup mutating_algorithms
77 * @param __t A thing of arbitrary type.
78 * @return Same, moved.
80 template<typename _Tp>
81 inline typename std::remove_reference<_Tp>::type&&
83 { return static_cast<typename std::remove_reference<_Tp>::type&&>(__t); }
85 /// declval, from type_traits.
88 * @brief Returns the actual address of the object or function
89 * referenced by r, even in the presence of an overloaded
91 * @param __r Reference to an object or function.
92 * @return The actual address.
94 template<typename _Tp>
97 { return std::__addressof(__r); }
99 _GLIBCXX_END_NAMESPACE_VERSION
102 #define _GLIBCXX_MOVE(__val) std::move(__val)
103 #define _GLIBCXX_FORWARD(_Tp, __val) std::forward<_Tp>(__val)
105 #define _GLIBCXX_MOVE(__val) (__val)
106 #define _GLIBCXX_FORWARD(_Tp, __val) (__val)
109 namespace std _GLIBCXX_VISIBILITY(default)
111 _GLIBCXX_BEGIN_NAMESPACE_VERSION
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.
120 template<typename _Tp>
122 swap(_Tp& __a, _Tp& __b)
124 // concept requirements
125 __glibcxx_function_requires(_SGIAssignableConcept<_Tp>)
127 _Tp __tmp = _GLIBCXX_MOVE(__a);
128 __a = _GLIBCXX_MOVE(__b);
129 __b = _GLIBCXX_MOVE(__tmp);
132 // _GLIBCXX_RESOLVE_LIB_DEFECTS
133 // DR 809. std::swap should be overloaded for array types.
134 template<typename _Tp, size_t _Nm>
136 swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
138 for (size_t __n = 0; __n < _Nm; ++__n)
139 swap(__a[__n], __b[__n]);
142 _GLIBCXX_END_NAMESPACE_VERSION