526e9a2a50
Backport from mainline 2017-12-01 Jonathan Wakely <jwakely@redhat.com> * include/std/type_traits (integral_constant): Make member functions noexcept (LWG 2346). * include/std/utility (integer_sequence): Likewise. From-SVN: r255328
412 lines
12 KiB
C++
412 lines
12 KiB
C++
// <utility> -*- C++ -*-
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// Copyright (C) 2001-2017 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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/*
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*
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* Copyright (c) 1994
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* Hewlett-Packard Company
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*
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* Permission to use, copy, modify, distribute and sell this software
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* and its documentation for any purpose is hereby granted without fee,
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* provided that the above copyright notice appear in all copies and
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* that both that copyright notice and this permission notice appear
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* in supporting documentation. Hewlett-Packard Company makes no
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* representations about the suitability of this software for any
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* purpose. It is provided "as is" without express or implied warranty.
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*
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*
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* Copyright (c) 1996,1997
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* Silicon Graphics Computer Systems, Inc.
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*
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* Permission to use, copy, modify, distribute and sell this software
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* and its documentation for any purpose is hereby granted without fee,
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* provided that the above copyright notice appear in all copies and
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* that both that copyright notice and this permission notice appear
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* in supporting documentation. Silicon Graphics makes no
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* representations about the suitability of this software for any
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* purpose. It is provided "as is" without express or implied warranty.
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*/
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/** @file include/utility
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* This is a Standard C++ Library header.
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*/
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#ifndef _GLIBCXX_UTILITY
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#define _GLIBCXX_UTILITY 1
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#pragma GCC system_header
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/**
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* @defgroup utilities Utilities
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*
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* Components deemed generally useful. Includes pair, tuple,
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* forward/move helpers, ratio, function object, metaprogramming and
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* type traits, time, date, and memory functions.
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*/
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#include <bits/c++config.h>
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#include <bits/stl_relops.h>
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#include <bits/stl_pair.h>
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#if __cplusplus >= 201103L
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#include <type_traits>
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#include <bits/move.h>
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#include <initializer_list>
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#if __cplusplus > 201402L
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#include <exception>
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#endif
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namespace std _GLIBCXX_VISIBILITY(default)
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{
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_GLIBCXX_BEGIN_NAMESPACE_VERSION
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/// Finds the size of a given tuple type.
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template<typename _Tp>
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struct tuple_size;
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// 2770. tuple_size<const T> specialization is not SFINAE compatible
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#if __cplusplus <= 201402L
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template<typename _Tp, typename = void>
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struct __tuple_size_cv_impl { };
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template<typename _Tp>
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struct __tuple_size_cv_impl<_Tp, __void_t<decltype(tuple_size<_Tp>::value)>>
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: integral_constant<size_t, tuple_size<_Tp>::value> { };
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// 2313. tuple_size should always derive from integral_constant<size_t, N>
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template<typename _Tp>
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struct tuple_size<const _Tp> : __tuple_size_cv_impl<_Tp> { };
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template<typename _Tp>
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struct tuple_size<volatile _Tp> : __tuple_size_cv_impl<_Tp> { };
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template<typename _Tp>
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struct tuple_size<const volatile _Tp> : __tuple_size_cv_impl<_Tp> { };
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#else
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template<typename _Tp,
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typename _Up = typename remove_cv<_Tp>::type,
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typename = typename enable_if<is_same<_Tp, _Up>::value>::type,
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size_t = tuple_size<_Tp>::value>
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using __enable_if_has_tuple_size = _Tp;
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template<typename _Tp>
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struct tuple_size<const __enable_if_has_tuple_size<_Tp>>
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: public tuple_size<_Tp> { };
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template<typename _Tp>
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struct tuple_size<volatile __enable_if_has_tuple_size<_Tp>>
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: public tuple_size<_Tp> { };
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template<typename _Tp>
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struct tuple_size<const volatile __enable_if_has_tuple_size<_Tp>>
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: public tuple_size<_Tp> { };
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#endif
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/// Gives the type of the ith element of a given tuple type.
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template<std::size_t __i, typename _Tp>
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struct tuple_element;
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// Duplicate of C++14's tuple_element_t for internal use in C++11 mode
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template<std::size_t __i, typename _Tp>
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using __tuple_element_t = typename tuple_element<__i, _Tp>::type;
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template<std::size_t __i, typename _Tp>
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struct tuple_element<__i, const _Tp>
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{
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typedef typename add_const<__tuple_element_t<__i, _Tp>>::type type;
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};
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template<std::size_t __i, typename _Tp>
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struct tuple_element<__i, volatile _Tp>
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{
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typedef typename add_volatile<__tuple_element_t<__i, _Tp>>::type type;
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};
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template<std::size_t __i, typename _Tp>
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struct tuple_element<__i, const volatile _Tp>
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{
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typedef typename add_cv<__tuple_element_t<__i, _Tp>>::type type;
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};
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#if __cplusplus > 201103L
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#define __cpp_lib_tuple_element_t 201402
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template<std::size_t __i, typename _Tp>
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using tuple_element_t = typename tuple_element<__i, _Tp>::type;
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#endif
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// Various functions which give std::pair a tuple-like interface.
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/// Partial specialization for std::pair
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template<typename _T1, typename _T2>
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struct __is_tuple_like_impl<std::pair<_T1, _T2>> : true_type
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{ };
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/// Partial specialization for std::pair
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template<class _Tp1, class _Tp2>
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struct tuple_size<std::pair<_Tp1, _Tp2>>
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: public integral_constant<std::size_t, 2> { };
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/// Partial specialization for std::pair
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template<class _Tp1, class _Tp2>
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struct tuple_element<0, std::pair<_Tp1, _Tp2>>
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{ typedef _Tp1 type; };
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/// Partial specialization for std::pair
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template<class _Tp1, class _Tp2>
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struct tuple_element<1, std::pair<_Tp1, _Tp2>>
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{ typedef _Tp2 type; };
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template<std::size_t _Int>
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struct __pair_get;
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template<>
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struct __pair_get<0>
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{
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template<typename _Tp1, typename _Tp2>
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static constexpr _Tp1&
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__get(std::pair<_Tp1, _Tp2>& __pair) noexcept
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{ return __pair.first; }
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template<typename _Tp1, typename _Tp2>
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static constexpr _Tp1&&
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__move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
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{ return std::forward<_Tp1>(__pair.first); }
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template<typename _Tp1, typename _Tp2>
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static constexpr const _Tp1&
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__const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
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{ return __pair.first; }
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};
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template<>
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struct __pair_get<1>
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{
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template<typename _Tp1, typename _Tp2>
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static constexpr _Tp2&
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__get(std::pair<_Tp1, _Tp2>& __pair) noexcept
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{ return __pair.second; }
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template<typename _Tp1, typename _Tp2>
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static constexpr _Tp2&&
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__move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
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{ return std::forward<_Tp2>(__pair.second); }
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template<typename _Tp1, typename _Tp2>
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static constexpr const _Tp2&
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__const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
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{ return __pair.second; }
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};
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template<std::size_t _Int, class _Tp1, class _Tp2>
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constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
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get(std::pair<_Tp1, _Tp2>& __in) noexcept
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{ return __pair_get<_Int>::__get(__in); }
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template<std::size_t _Int, class _Tp1, class _Tp2>
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constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
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get(std::pair<_Tp1, _Tp2>&& __in) noexcept
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{ return __pair_get<_Int>::__move_get(std::move(__in)); }
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template<std::size_t _Int, class _Tp1, class _Tp2>
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constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
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get(const std::pair<_Tp1, _Tp2>& __in) noexcept
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{ return __pair_get<_Int>::__const_get(__in); }
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#if __cplusplus > 201103L
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#define __cpp_lib_tuples_by_type 201304
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template <typename _Tp, typename _Up>
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constexpr _Tp&
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get(pair<_Tp, _Up>& __p) noexcept
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{ return __p.first; }
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template <typename _Tp, typename _Up>
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constexpr const _Tp&
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get(const pair<_Tp, _Up>& __p) noexcept
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{ return __p.first; }
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template <typename _Tp, typename _Up>
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constexpr _Tp&&
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get(pair<_Tp, _Up>&& __p) noexcept
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{ return std::move(__p.first); }
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template <typename _Tp, typename _Up>
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constexpr _Tp&
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get(pair<_Up, _Tp>& __p) noexcept
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{ return __p.second; }
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template <typename _Tp, typename _Up>
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constexpr const _Tp&
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get(const pair<_Up, _Tp>& __p) noexcept
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{ return __p.second; }
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template <typename _Tp, typename _Up>
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constexpr _Tp&&
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get(pair<_Up, _Tp>&& __p) noexcept
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{ return std::move(__p.second); }
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#define __cpp_lib_exchange_function 201304
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/// Assign @p __new_val to @p __obj and return its previous value.
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template <typename _Tp, typename _Up = _Tp>
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inline _Tp
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exchange(_Tp& __obj, _Up&& __new_val)
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{ return std::__exchange(__obj, std::forward<_Up>(__new_val)); }
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#endif
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// Stores a tuple of indices. Used by tuple and pair, and by bind() to
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// extract the elements in a tuple.
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template<size_t... _Indexes> struct _Index_tuple { };
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// Concatenates two _Index_tuples.
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template<typename _Itup1, typename _Itup2> struct _Itup_cat;
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template<size_t... _Ind1, size_t... _Ind2>
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struct _Itup_cat<_Index_tuple<_Ind1...>, _Index_tuple<_Ind2...>>
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{
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using __type = _Index_tuple<_Ind1..., (_Ind2 + sizeof...(_Ind1))...>;
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};
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// Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
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template<size_t _Num>
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struct _Build_index_tuple
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: _Itup_cat<typename _Build_index_tuple<_Num / 2>::__type,
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typename _Build_index_tuple<_Num - _Num / 2>::__type>
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{ };
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template<>
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struct _Build_index_tuple<1>
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{
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typedef _Index_tuple<0> __type;
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};
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template<>
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struct _Build_index_tuple<0>
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{
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typedef _Index_tuple<> __type;
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};
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#if __cplusplus > 201103L
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#define __cpp_lib_integer_sequence 201304
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/// Class template integer_sequence
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template<typename _Tp, _Tp... _Idx>
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struct integer_sequence
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{
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typedef _Tp value_type;
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static constexpr size_t size() noexcept { return sizeof...(_Idx); }
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};
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template<typename _Tp, _Tp _Num,
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typename _ISeq = typename _Build_index_tuple<_Num>::__type>
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struct _Make_integer_sequence;
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template<typename _Tp, _Tp _Num, size_t... _Idx>
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struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>>
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{
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static_assert( _Num >= 0,
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"Cannot make integer sequence of negative length" );
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typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type;
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};
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/// Alias template make_integer_sequence
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template<typename _Tp, _Tp _Num>
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using make_integer_sequence
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= typename _Make_integer_sequence<_Tp, _Num>::__type;
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/// Alias template index_sequence
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template<size_t... _Idx>
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using index_sequence = integer_sequence<size_t, _Idx...>;
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/// Alias template make_index_sequence
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template<size_t _Num>
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using make_index_sequence = make_integer_sequence<size_t, _Num>;
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/// Alias template index_sequence_for
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template<typename... _Types>
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using index_sequence_for = make_index_sequence<sizeof...(_Types)>;
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#endif
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#if __cplusplus > 201402L
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struct in_place_t {
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explicit in_place_t() = default;
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};
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inline constexpr in_place_t in_place{};
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template<typename _Tp> struct in_place_type_t
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{
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explicit in_place_type_t() = default;
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};
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template<typename _Tp>
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inline constexpr in_place_type_t<_Tp> in_place_type{};
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template<size_t _Idx> struct in_place_index_t
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{
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explicit in_place_index_t() = default;
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};
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template<size_t _Idx>
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inline constexpr in_place_index_t<_Idx> in_place_index{};
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template<typename>
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struct __is_in_place_type_impl : false_type
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{ };
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template<typename _Tp>
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struct __is_in_place_type_impl<in_place_type_t<_Tp>> : true_type
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{ };
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template<typename _Tp>
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struct __is_in_place_type
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: public __is_in_place_type_impl<_Tp>
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{ };
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#define __cpp_lib_as_const 201510
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template<typename _Tp>
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constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
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template<typename _Tp>
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void as_const(const _Tp&&) = delete;
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#endif // C++17
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_GLIBCXX_END_NAMESPACE_VERSION
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} // namespace
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#endif
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#endif /* _GLIBCXX_UTILITY */
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