1*e4b17023SJohn Marino // Move, forward and identity for C++0x + swap -*- C++ -*-
2*e4b17023SJohn Marino
3*e4b17023SJohn Marino // Copyright (C) 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4*e4b17023SJohn Marino //
5*e4b17023SJohn Marino // This file is part of the GNU ISO C++ Library. This library is free
6*e4b17023SJohn Marino // software; you can redistribute it and/or modify it under the
7*e4b17023SJohn Marino // terms of the GNU General Public License as published by the
8*e4b17023SJohn Marino // Free Software Foundation; either version 3, or (at your option)
9*e4b17023SJohn Marino // any later version.
10*e4b17023SJohn Marino
11*e4b17023SJohn Marino // This library is distributed in the hope that it will be useful,
12*e4b17023SJohn Marino // but WITHOUT ANY WARRANTY; without even the implied warranty of
13*e4b17023SJohn Marino // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14*e4b17023SJohn Marino // GNU General Public License for more details.
15*e4b17023SJohn Marino
16*e4b17023SJohn Marino // Under Section 7 of GPL version 3, you are granted additional
17*e4b17023SJohn Marino // permissions described in the GCC Runtime Library Exception, version
18*e4b17023SJohn Marino // 3.1, as published by the Free Software Foundation.
19*e4b17023SJohn Marino
20*e4b17023SJohn Marino // You should have received a copy of the GNU General Public License and
21*e4b17023SJohn Marino // a copy of the GCC Runtime Library Exception along with this program;
22*e4b17023SJohn Marino // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23*e4b17023SJohn Marino // <http://www.gnu.org/licenses/>.
24*e4b17023SJohn Marino
25*e4b17023SJohn Marino /** @file bits/move.h
26*e4b17023SJohn Marino * This is an internal header file, included by other library headers.
27*e4b17023SJohn Marino * Do not attempt to use it directly. @headername{utility}
28*e4b17023SJohn Marino */
29*e4b17023SJohn Marino
30*e4b17023SJohn Marino #ifndef _MOVE_H
31*e4b17023SJohn Marino #define _MOVE_H 1
32*e4b17023SJohn Marino
33*e4b17023SJohn Marino #include <bits/c++config.h>
34*e4b17023SJohn Marino #include <bits/concept_check.h>
35*e4b17023SJohn Marino
_GLIBCXX_VISIBILITY(default)36*e4b17023SJohn Marino namespace std _GLIBCXX_VISIBILITY(default)
37*e4b17023SJohn Marino {
38*e4b17023SJohn Marino _GLIBCXX_BEGIN_NAMESPACE_VERSION
39*e4b17023SJohn Marino
40*e4b17023SJohn Marino // Used, in C++03 mode too, by allocators, etc.
41*e4b17023SJohn Marino /**
42*e4b17023SJohn Marino * @brief Same as C++11 std::addressof
43*e4b17023SJohn Marino * @ingroup utilities
44*e4b17023SJohn Marino */
45*e4b17023SJohn Marino template<typename _Tp>
46*e4b17023SJohn Marino inline _Tp*
47*e4b17023SJohn Marino __addressof(_Tp& __r) _GLIBCXX_NOEXCEPT
48*e4b17023SJohn Marino {
49*e4b17023SJohn Marino return reinterpret_cast<_Tp*>
50*e4b17023SJohn Marino (&const_cast<char&>(reinterpret_cast<const volatile char&>(__r)));
51*e4b17023SJohn Marino }
52*e4b17023SJohn Marino
53*e4b17023SJohn Marino _GLIBCXX_END_NAMESPACE_VERSION
54*e4b17023SJohn Marino } // namespace
55*e4b17023SJohn Marino
56*e4b17023SJohn Marino #ifdef __GXX_EXPERIMENTAL_CXX0X__
57*e4b17023SJohn Marino #include <type_traits> // Brings in std::declval too.
58*e4b17023SJohn Marino
_GLIBCXX_VISIBILITY(default)59*e4b17023SJohn Marino namespace std _GLIBCXX_VISIBILITY(default)
60*e4b17023SJohn Marino {
61*e4b17023SJohn Marino _GLIBCXX_BEGIN_NAMESPACE_VERSION
62*e4b17023SJohn Marino
63*e4b17023SJohn Marino /**
64*e4b17023SJohn Marino * @addtogroup utilities
65*e4b17023SJohn Marino * @{
66*e4b17023SJohn Marino */
67*e4b17023SJohn Marino
68*e4b17023SJohn Marino // forward (as per N3143)
69*e4b17023SJohn Marino /**
70*e4b17023SJohn Marino * @brief Forward an lvalue.
71*e4b17023SJohn Marino * @return The parameter cast to the specified type.
72*e4b17023SJohn Marino *
73*e4b17023SJohn Marino * This function is used to implement "perfect forwarding".
74*e4b17023SJohn Marino */
75*e4b17023SJohn Marino template<typename _Tp>
76*e4b17023SJohn Marino constexpr _Tp&&
77*e4b17023SJohn Marino forward(typename std::remove_reference<_Tp>::type& __t) noexcept
78*e4b17023SJohn Marino { return static_cast<_Tp&&>(__t); }
79*e4b17023SJohn Marino
80*e4b17023SJohn Marino /**
81*e4b17023SJohn Marino * @brief Forward an rvalue.
82*e4b17023SJohn Marino * @return The parameter cast to the specified type.
83*e4b17023SJohn Marino *
84*e4b17023SJohn Marino * This function is used to implement "perfect forwarding".
85*e4b17023SJohn Marino */
86*e4b17023SJohn Marino template<typename _Tp>
87*e4b17023SJohn Marino constexpr _Tp&&
88*e4b17023SJohn Marino forward(typename std::remove_reference<_Tp>::type&& __t) noexcept
89*e4b17023SJohn Marino {
90*e4b17023SJohn Marino static_assert(!std::is_lvalue_reference<_Tp>::value, "template argument"
91*e4b17023SJohn Marino " substituting _Tp is an lvalue reference type");
92*e4b17023SJohn Marino return static_cast<_Tp&&>(__t);
93*e4b17023SJohn Marino }
94*e4b17023SJohn Marino
95*e4b17023SJohn Marino /**
96*e4b17023SJohn Marino * @brief Convert a value to an rvalue.
97*e4b17023SJohn Marino * @param __t A thing of arbitrary type.
98*e4b17023SJohn Marino * @return The parameter cast to an rvalue-reference to allow moving it.
99*e4b17023SJohn Marino */
100*e4b17023SJohn Marino template<typename _Tp>
101*e4b17023SJohn Marino constexpr typename std::remove_reference<_Tp>::type&&
102*e4b17023SJohn Marino move(_Tp&& __t) noexcept
103*e4b17023SJohn Marino { return static_cast<typename std::remove_reference<_Tp>::type&&>(__t); }
104*e4b17023SJohn Marino
105*e4b17023SJohn Marino
106*e4b17023SJohn Marino template<typename _Tp>
107*e4b17023SJohn Marino struct __move_if_noexcept_cond
108*e4b17023SJohn Marino : public __and_<__not_<is_nothrow_move_constructible<_Tp>>,
109*e4b17023SJohn Marino is_copy_constructible<_Tp>>::type { };
110*e4b17023SJohn Marino
111*e4b17023SJohn Marino /**
112*e4b17023SJohn Marino * @brief Conditionally convert a value to an rvalue.
113*e4b17023SJohn Marino * @param __x A thing of arbitrary type.
114*e4b17023SJohn Marino * @return The parameter, possibly cast to an rvalue-reference.
115*e4b17023SJohn Marino *
116*e4b17023SJohn Marino * Same as std::move unless the type's move constructor could throw and the
117*e4b17023SJohn Marino * type is copyable, in which case an lvalue-reference is returned instead.
118*e4b17023SJohn Marino */
119*e4b17023SJohn Marino template<typename _Tp>
120*e4b17023SJohn Marino inline typename
121*e4b17023SJohn Marino conditional<__move_if_noexcept_cond<_Tp>::value, const _Tp&, _Tp&&>::type
122*e4b17023SJohn Marino move_if_noexcept(_Tp& __x) noexcept
123*e4b17023SJohn Marino { return std::move(__x); }
124*e4b17023SJohn Marino
125*e4b17023SJohn Marino // declval, from type_traits.
126*e4b17023SJohn Marino
127*e4b17023SJohn Marino /**
128*e4b17023SJohn Marino * @brief Returns the actual address of the object or function
129*e4b17023SJohn Marino * referenced by r, even in the presence of an overloaded
130*e4b17023SJohn Marino * operator&.
131*e4b17023SJohn Marino * @param __r Reference to an object or function.
132*e4b17023SJohn Marino * @return The actual address.
133*e4b17023SJohn Marino */
134*e4b17023SJohn Marino template<typename _Tp>
135*e4b17023SJohn Marino inline _Tp*
136*e4b17023SJohn Marino addressof(_Tp& __r) noexcept
137*e4b17023SJohn Marino { return std::__addressof(__r); }
138*e4b17023SJohn Marino
139*e4b17023SJohn Marino /// @} group utilities
140*e4b17023SJohn Marino _GLIBCXX_END_NAMESPACE_VERSION
141*e4b17023SJohn Marino } // namespace
142*e4b17023SJohn Marino
143*e4b17023SJohn Marino #define _GLIBCXX_MOVE(__val) std::move(__val)
144*e4b17023SJohn Marino #define _GLIBCXX_FORWARD(_Tp, __val) std::forward<_Tp>(__val)
145*e4b17023SJohn Marino #else
146*e4b17023SJohn Marino #define _GLIBCXX_MOVE(__val) (__val)
147*e4b17023SJohn Marino #define _GLIBCXX_FORWARD(_Tp, __val) (__val)
148*e4b17023SJohn Marino #endif
149*e4b17023SJohn Marino
_GLIBCXX_VISIBILITY(default)150*e4b17023SJohn Marino namespace std _GLIBCXX_VISIBILITY(default)
151*e4b17023SJohn Marino {
152*e4b17023SJohn Marino _GLIBCXX_BEGIN_NAMESPACE_VERSION
153*e4b17023SJohn Marino
154*e4b17023SJohn Marino /**
155*e4b17023SJohn Marino * @addtogroup utilities
156*e4b17023SJohn Marino * @{
157*e4b17023SJohn Marino */
158*e4b17023SJohn Marino
159*e4b17023SJohn Marino /**
160*e4b17023SJohn Marino * @brief Swaps two values.
161*e4b17023SJohn Marino * @param __a A thing of arbitrary type.
162*e4b17023SJohn Marino * @param __b Another thing of arbitrary type.
163*e4b17023SJohn Marino * @return Nothing.
164*e4b17023SJohn Marino */
165*e4b17023SJohn Marino template<typename _Tp>
166*e4b17023SJohn Marino inline void
167*e4b17023SJohn Marino swap(_Tp& __a, _Tp& __b)
168*e4b17023SJohn Marino #ifdef __GXX_EXPERIMENTAL_CXX0X__
169*e4b17023SJohn Marino noexcept(__and_<is_nothrow_move_constructible<_Tp>,
170*e4b17023SJohn Marino is_nothrow_move_assignable<_Tp>>::value)
171*e4b17023SJohn Marino #endif
172*e4b17023SJohn Marino {
173*e4b17023SJohn Marino // concept requirements
174*e4b17023SJohn Marino __glibcxx_function_requires(_SGIAssignableConcept<_Tp>)
175*e4b17023SJohn Marino
176*e4b17023SJohn Marino _Tp __tmp = _GLIBCXX_MOVE(__a);
177*e4b17023SJohn Marino __a = _GLIBCXX_MOVE(__b);
178*e4b17023SJohn Marino __b = _GLIBCXX_MOVE(__tmp);
179*e4b17023SJohn Marino }
180*e4b17023SJohn Marino
181*e4b17023SJohn Marino // _GLIBCXX_RESOLVE_LIB_DEFECTS
182*e4b17023SJohn Marino // DR 809. std::swap should be overloaded for array types.
183*e4b17023SJohn Marino /// Swap the contents of two arrays.
184*e4b17023SJohn Marino template<typename _Tp, size_t _Nm>
185*e4b17023SJohn Marino inline void
186*e4b17023SJohn Marino swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
187*e4b17023SJohn Marino #ifdef __GXX_EXPERIMENTAL_CXX0X__
188*e4b17023SJohn Marino noexcept(noexcept(swap(*__a, *__b)))
189*e4b17023SJohn Marino #endif
190*e4b17023SJohn Marino {
191*e4b17023SJohn Marino for (size_t __n = 0; __n < _Nm; ++__n)
192*e4b17023SJohn Marino swap(__a[__n], __b[__n]);
193*e4b17023SJohn Marino }
194*e4b17023SJohn Marino
195*e4b17023SJohn Marino /// @} group utilities
196*e4b17023SJohn Marino _GLIBCXX_END_NAMESPACE_VERSION
197*e4b17023SJohn Marino } // namespace
198*e4b17023SJohn Marino
199*e4b17023SJohn Marino #endif /* _MOVE_H */
200