libstdc++
utility
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00001 // <utility> -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2013 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /*
00026  *
00027  * Copyright (c) 1994
00028  * Hewlett-Packard Company
00029  *
00030  * Permission to use, copy, modify, distribute and sell this software
00031  * and its documentation for any purpose is hereby granted without fee,
00032  * provided that the above copyright notice appear in all copies and
00033  * that both that copyright notice and this permission notice appear
00034  * in supporting documentation.  Hewlett-Packard Company makes no
00035  * representations about the suitability of this software for any
00036  * purpose.  It is provided "as is" without express or implied warranty.
00037  *
00038  *
00039  * Copyright (c) 1996,1997
00040  * Silicon Graphics Computer Systems, Inc.
00041  *
00042  * Permission to use, copy, modify, distribute and sell this software
00043  * and its documentation for any purpose is hereby granted without fee,
00044  * provided that the above copyright notice appear in all copies and
00045  * that both that copyright notice and this permission notice appear
00046  * in supporting documentation.  Silicon Graphics makes no
00047  * representations about the suitability of this software for any
00048  * purpose.  It is provided "as is" without express or implied warranty.
00049  */
00050 
00051 /** @file include/utility
00052  *  This is a Standard C++ Library header. 
00053  */
00054 
00055 #ifndef _GLIBCXX_UTILITY
00056 #define _GLIBCXX_UTILITY 1
00057 
00058 #pragma GCC system_header
00059 
00060 /**
00061  * @defgroup utilities Utilities
00062  *
00063  * Components deemed generally useful. Includes pair, tuple,
00064  * forward/move helpers, ratio, function object, metaprogramming and
00065  * type traits, time, date, and memory functions.
00066  */
00067 
00068 #include <bits/c++config.h>
00069 #include <bits/stl_relops.h>
00070 #include <bits/stl_pair.h>
00071 
00072 #if __cplusplus >= 201103L
00073 #include <bits/move.h>
00074 #include <initializer_list>
00075 
00076 namespace std _GLIBCXX_VISIBILITY(default)
00077 {
00078 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00079 
00080   template<class _Tp>
00081     class tuple_size;
00082 
00083   template<std::size_t _Int, class _Tp>
00084     class tuple_element;
00085 
00086    // Various functions which give std::pair a tuple-like interface.
00087   template<class _Tp1, class _Tp2>
00088     struct tuple_size<std::pair<_Tp1, _Tp2>>
00089     : public integral_constant<std::size_t, 2> { };
00090 
00091   template<class _Tp1, class _Tp2>
00092     struct tuple_element<0, std::pair<_Tp1, _Tp2>>
00093     { typedef _Tp1 type; };
00094  
00095   template<class _Tp1, class _Tp2>
00096     struct tuple_element<1, std::pair<_Tp1, _Tp2>>
00097     { typedef _Tp2 type; };
00098 
00099   template<std::size_t _Int>
00100     struct __pair_get;
00101 
00102   template<>
00103     struct __pair_get<0>
00104     {
00105       template<typename _Tp1, typename _Tp2>
00106         static constexpr _Tp1&
00107         __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
00108         { return __pair.first; }
00109 
00110       template<typename _Tp1, typename _Tp2>
00111         static constexpr _Tp1&&
00112         __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
00113         { return std::forward<_Tp1>(__pair.first); }
00114 
00115       template<typename _Tp1, typename _Tp2>
00116         static constexpr const _Tp1&
00117         __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
00118         { return __pair.first; }
00119     };
00120 
00121   template<>
00122     struct __pair_get<1>
00123     {
00124       template<typename _Tp1, typename _Tp2>
00125         static constexpr _Tp2&
00126         __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
00127         { return __pair.second; }
00128 
00129       template<typename _Tp1, typename _Tp2>
00130         static constexpr _Tp2&&
00131         __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
00132         { return std::forward<_Tp2>(__pair.second); }
00133 
00134       template<typename _Tp1, typename _Tp2>
00135         static constexpr const _Tp2&
00136         __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
00137         { return __pair.second; }
00138     };
00139 
00140   template<std::size_t _Int, class _Tp1, class _Tp2>
00141     constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
00142     get(std::pair<_Tp1, _Tp2>& __in) noexcept
00143     { return __pair_get<_Int>::__get(__in); }
00144 
00145   template<std::size_t _Int, class _Tp1, class _Tp2>
00146     constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
00147     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
00148     { return __pair_get<_Int>::__move_get(std::move(__in)); }
00149 
00150   template<std::size_t _Int, class _Tp1, class _Tp2>
00151     constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
00152     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
00153     { return __pair_get<_Int>::__const_get(__in); }
00154 
00155 _GLIBCXX_END_NAMESPACE_VERSION
00156 } // namespace
00157 
00158 #endif
00159 
00160 #endif /* _GLIBCXX_UTILITY */