libstdc++
utility
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00001 // <utility> -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2015 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 
00074 #include <bits/move.h>
00075 #include <initializer_list>
00076 
00077 namespace std _GLIBCXX_VISIBILITY(default)
00078 {
00079 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00080 
00081   template<class _Tp>
00082     class tuple_size;
00083 
00084   template<std::size_t _Int, class _Tp>
00085     class tuple_element;
00086 
00087    // Various functions which give std::pair a tuple-like interface.
00088 
00089   /// Partial specialization for std::pair
00090   template<class _Tp1, class _Tp2>
00091     struct tuple_size<std::pair<_Tp1, _Tp2>>
00092     : public integral_constant<std::size_t, 2> { };
00093 
00094   /// Partial specialization for std::pair
00095   template<class _Tp1, class _Tp2>
00096     struct tuple_element<0, std::pair<_Tp1, _Tp2>>
00097     { typedef _Tp1 type; };
00098  
00099   /// Partial specialization for std::pair
00100   template<class _Tp1, class _Tp2>
00101     struct tuple_element<1, std::pair<_Tp1, _Tp2>>
00102     { typedef _Tp2 type; };
00103 
00104   template<std::size_t _Int>
00105     struct __pair_get;
00106 
00107   template<>
00108     struct __pair_get<0>
00109     {
00110       template<typename _Tp1, typename _Tp2>
00111         static constexpr _Tp1&
00112         __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
00113         { return __pair.first; }
00114 
00115       template<typename _Tp1, typename _Tp2>
00116         static constexpr _Tp1&&
00117         __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
00118         { return std::forward<_Tp1>(__pair.first); }
00119 
00120       template<typename _Tp1, typename _Tp2>
00121         static constexpr const _Tp1&
00122         __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
00123         { return __pair.first; }
00124     };
00125 
00126   template<>
00127     struct __pair_get<1>
00128     {
00129       template<typename _Tp1, typename _Tp2>
00130         static constexpr _Tp2&
00131         __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
00132         { return __pair.second; }
00133 
00134       template<typename _Tp1, typename _Tp2>
00135         static constexpr _Tp2&&
00136         __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
00137         { return std::forward<_Tp2>(__pair.second); }
00138 
00139       template<typename _Tp1, typename _Tp2>
00140         static constexpr const _Tp2&
00141         __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
00142         { return __pair.second; }
00143     };
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>::__get(__in); }
00149 
00150   template<std::size_t _Int, class _Tp1, class _Tp2>
00151     constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
00152     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
00153     { return __pair_get<_Int>::__move_get(std::move(__in)); }
00154 
00155   template<std::size_t _Int, class _Tp1, class _Tp2>
00156     constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
00157     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
00158     { return __pair_get<_Int>::__const_get(__in); }
00159 
00160 #if __cplusplus > 201103L
00161 
00162 #define __cpp_lib_tuples_by_type 201304
00163 
00164   template <typename _Tp, typename _Up>
00165     constexpr _Tp&
00166     get(pair<_Tp, _Up>& __p) noexcept
00167     { return __p.first; }
00168 
00169   template <typename _Tp, typename _Up>
00170     constexpr const _Tp&
00171     get(const pair<_Tp, _Up>& __p) noexcept
00172     { return __p.first; }
00173 
00174   template <typename _Tp, typename _Up>
00175     constexpr _Tp&&
00176     get(pair<_Tp, _Up>&& __p) noexcept
00177     { return std::move(__p.first); }
00178 
00179   template <typename _Tp, typename _Up>
00180     constexpr _Tp&
00181     get(pair<_Up, _Tp>& __p) noexcept
00182     { return __p.second; }
00183 
00184   template <typename _Tp, typename _Up>
00185     constexpr const _Tp&
00186     get(const pair<_Up, _Tp>& __p) noexcept
00187     { return __p.second; }
00188 
00189   template <typename _Tp, typename _Up>
00190     constexpr _Tp&&
00191     get(pair<_Up, _Tp>&& __p) noexcept
00192     { return std::move(__p.second); }
00193 
00194 #define __cpp_lib_exchange_function 201304
00195 
00196   /// Assign @p __new_val to @p __obj and return its previous value.
00197   template <typename _Tp, typename _Up = _Tp>
00198     inline _Tp
00199     exchange(_Tp& __obj, _Up&& __new_val)
00200     { return std::__exchange(__obj, std::forward<_Up>(__new_val)); }
00201 #endif
00202 
00203   // Stores a tuple of indices.  Used by tuple and pair, and by bind() to
00204   // extract the elements in a tuple.
00205   template<size_t... _Indexes>
00206     struct _Index_tuple
00207     {
00208       typedef _Index_tuple<_Indexes..., sizeof...(_Indexes)> __next;
00209     };
00210 
00211   // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
00212   template<size_t _Num>
00213     struct _Build_index_tuple
00214     {
00215       typedef typename _Build_index_tuple<_Num - 1>::__type::__next __type;
00216     };
00217 
00218   template<>
00219     struct _Build_index_tuple<0>
00220     {
00221       typedef _Index_tuple<> __type;
00222     };
00223 
00224 #if __cplusplus > 201103L
00225 
00226 #define __cpp_lib_integer_sequence 201304
00227 
00228   /// Class template integer_sequence
00229   template<typename _Tp, _Tp... _Idx>
00230     struct integer_sequence
00231     {
00232       typedef _Tp value_type;
00233       static constexpr size_t size() { return sizeof...(_Idx); }
00234     };
00235 
00236   template<typename _Tp, _Tp _Num,
00237            typename _ISeq = typename _Build_index_tuple<_Num>::__type>
00238     struct _Make_integer_sequence;
00239 
00240   template<typename _Tp, _Tp _Num,  size_t... _Idx>
00241     struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>>
00242     {
00243       static_assert( _Num >= 0,
00244                      "Cannot make integer sequence of negative length" );
00245 
00246       typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type;
00247     };
00248 
00249   /// Alias template make_integer_sequence
00250   template<typename _Tp, _Tp _Num>
00251     using make_integer_sequence
00252       = typename _Make_integer_sequence<_Tp, _Num>::__type;
00253 
00254   /// Alias template index_sequence
00255   template<size_t... _Idx>
00256     using index_sequence = integer_sequence<size_t, _Idx...>;
00257 
00258   /// Alias template make_index_sequence
00259   template<size_t _Num>
00260     using make_index_sequence = make_integer_sequence<size_t, _Num>;
00261 
00262   /// Alias template index_sequence_for
00263   template<typename... _Types>
00264     using index_sequence_for = make_index_sequence<sizeof...(_Types)>;
00265 #endif
00266 
00267 _GLIBCXX_END_NAMESPACE_VERSION
00268 } // namespace
00269 
00270 #endif
00271 
00272 #endif /* _GLIBCXX_UTILITY */