1 // Move, forward and identity for C++0x + swap -*- C++ -*- 2 3 // Copyright (C) 2007, 2008, 2009 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 move.h 26 * This is an internal header file, included by other library headers. 27 * You should not attempt to use it directly. 28 */ 29 30 #ifndef _MOVE_H 31 #define _MOVE_H 1 32 33 #include <bits/c++config.h> 34 #include <cstddef> 35 #include <bits/concept_check.h> 36 37 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 38 #include <type_traits> 39 40 _GLIBCXX_BEGIN_NAMESPACE(std) 41 42 // 20.2.2, forward/move 43 template<typename _Tp> 44 struct identity 45 { 46 typedef _Tp type; 47 }; 48 49 template<typename _Tp> 50 inline _Tp&& 51 forward(typename std::identity<_Tp>::type&& __t) 52 { return __t; } 53 54 template<typename _Tp> 55 inline typename std::remove_reference<_Tp>::type&& 56 move(_Tp&& __t) 57 { return __t; } 58 59 _GLIBCXX_END_NAMESPACE 60 61 #define _GLIBCXX_MOVE(_Tp) std::move(_Tp) 62 #else 63 #define _GLIBCXX_MOVE(_Tp) (_Tp) 64 #endif 65 66 _GLIBCXX_BEGIN_NAMESPACE(std) 67 68 /** 69 * @brief Swaps two values. 70 * @param a A thing of arbitrary type. 71 * @param b Another thing of arbitrary type. 72 * @return Nothing. 73 */ 74 template<typename _Tp> 75 inline void 76 swap(_Tp& __a, _Tp& __b) 77 { 78 // concept requirements 79 __glibcxx_function_requires(_SGIAssignableConcept<_Tp>) 80 81 _Tp __tmp = _GLIBCXX_MOVE(__a); 82 __a = _GLIBCXX_MOVE(__b); 83 __b = _GLIBCXX_MOVE(__tmp); 84 } 85 86 // _GLIBCXX_RESOLVE_LIB_DEFECTS 87 // DR 809. std::swap should be overloaded for array types. 88 template<typename _Tp, size_t _Nm> 89 inline void 90 swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm]) 91 { 92 for (size_t __n = 0; __n < _Nm; ++__n) 93 swap(__a[__n], __b[__n]); 94 } 95 96 _GLIBCXX_END_NAMESPACE 97 98 #endif /* _MOVE_H */ 99
