2a0c083558
I'm only treating this as a DR for C++20 for now, because it's less work and only requires changes to operator== and operator<=>. To do this for older standards would require changes to the six relational operators used pre-C++20. libstdc++-v3/ChangeLog: PR libstdc++/113386 * include/bits/stl_pair.h (operator==, operator<=>): Support heterogeneous comparisons, as per LWG 3865. * testsuite/20_util/pair/comparison_operators/lwg3865.cc: New test.
1335 lines
43 KiB
C++
1335 lines
43 KiB
C++
// Pair implementation -*- C++ -*-
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// Copyright (C) 2001-2024 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 bits/stl_pair.h
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* This is an internal header file, included by other library headers.
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* Do not attempt to use it directly. @headername{utility}
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*/
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#ifndef _STL_PAIR_H
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#define _STL_PAIR_H 1
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#if __cplusplus >= 201103L
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# include <type_traits> // for std::__decay_and_strip
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# include <bits/move.h> // for std::move / std::forward, and std::swap
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# include <bits/utility.h> // for std::tuple_element, std::tuple_size
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#endif
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#if __cplusplus >= 202002L
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# include <compare>
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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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/**
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* @addtogroup utilities
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* @{
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*/
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#if __cplusplus >= 201103L
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/// Tag type for piecewise construction of std::pair objects.
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struct piecewise_construct_t { explicit piecewise_construct_t() = default; };
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/// Tag for piecewise construction of std::pair objects.
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_GLIBCXX17_INLINE constexpr piecewise_construct_t piecewise_construct =
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piecewise_construct_t();
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/// @cond undocumented
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// Forward declarations.
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template<typename _T1, typename _T2>
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struct pair;
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template<typename...>
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class tuple;
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// Declarations of std::array and its std::get overloads, so that
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// std::tuple_cat can use them if <tuple> is included before <array>.
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// We also declare the other std::get overloads here so that they're
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// visible to the P2165R4 tuple-like constructors of pair and tuple.
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template<typename _Tp, size_t _Nm>
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struct array;
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template<size_t...>
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struct _Index_tuple;
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template<size_t _Int, class _Tp1, class _Tp2>
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constexpr typename tuple_element<_Int, pair<_Tp1, _Tp2>>::type&
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get(pair<_Tp1, _Tp2>& __in) noexcept;
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template<size_t _Int, class _Tp1, class _Tp2>
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constexpr typename tuple_element<_Int, pair<_Tp1, _Tp2>>::type&&
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get(pair<_Tp1, _Tp2>&& __in) noexcept;
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template<size_t _Int, class _Tp1, class _Tp2>
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constexpr const typename tuple_element<_Int, pair<_Tp1, _Tp2>>::type&
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get(const pair<_Tp1, _Tp2>& __in) noexcept;
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template<size_t _Int, class _Tp1, class _Tp2>
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constexpr const typename tuple_element<_Int, pair<_Tp1, _Tp2>>::type&&
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get(const pair<_Tp1, _Tp2>&& __in) noexcept;
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template<size_t __i, typename... _Elements>
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constexpr __tuple_element_t<__i, tuple<_Elements...>>&
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get(tuple<_Elements...>& __t) noexcept;
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template<size_t __i, typename... _Elements>
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constexpr const __tuple_element_t<__i, tuple<_Elements...>>&
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get(const tuple<_Elements...>& __t) noexcept;
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template<size_t __i, typename... _Elements>
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constexpr __tuple_element_t<__i, tuple<_Elements...>>&&
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get(tuple<_Elements...>&& __t) noexcept;
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template<size_t __i, typename... _Elements>
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constexpr const __tuple_element_t<__i, tuple<_Elements...>>&&
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get(const tuple<_Elements...>&& __t) noexcept;
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template<size_t _Int, typename _Tp, size_t _Nm>
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constexpr _Tp&
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get(array<_Tp, _Nm>&) noexcept;
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template<size_t _Int, typename _Tp, size_t _Nm>
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constexpr _Tp&&
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get(array<_Tp, _Nm>&&) noexcept;
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template<size_t _Int, typename _Tp, size_t _Nm>
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constexpr const _Tp&
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get(const array<_Tp, _Nm>&) noexcept;
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template<size_t _Int, typename _Tp, size_t _Nm>
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constexpr const _Tp&&
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get(const array<_Tp, _Nm>&&) noexcept;
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#if ! __cpp_lib_concepts
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// Concept utility functions, reused in conditionally-explicit
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// constructors.
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// See PR 70437, don't look at is_constructible or
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// is_convertible if the types are the same to
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// avoid querying those properties for incomplete types.
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template <bool, typename _T1, typename _T2>
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struct _PCC
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{
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template <typename _U1, typename _U2>
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static constexpr bool _ConstructiblePair()
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{
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return __and_<is_constructible<_T1, const _U1&>,
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is_constructible<_T2, const _U2&>>::value;
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}
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template <typename _U1, typename _U2>
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static constexpr bool _ImplicitlyConvertiblePair()
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{
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return __and_<is_convertible<const _U1&, _T1>,
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is_convertible<const _U2&, _T2>>::value;
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}
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template <typename _U1, typename _U2>
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static constexpr bool _MoveConstructiblePair()
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{
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return __and_<is_constructible<_T1, _U1&&>,
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is_constructible<_T2, _U2&&>>::value;
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}
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template <typename _U1, typename _U2>
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static constexpr bool _ImplicitlyMoveConvertiblePair()
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{
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return __and_<is_convertible<_U1&&, _T1>,
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is_convertible<_U2&&, _T2>>::value;
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}
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};
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template <typename _T1, typename _T2>
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struct _PCC<false, _T1, _T2>
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{
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template <typename _U1, typename _U2>
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static constexpr bool _ConstructiblePair()
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{
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return false;
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}
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template <typename _U1, typename _U2>
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static constexpr bool _ImplicitlyConvertiblePair()
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{
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return false;
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}
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template <typename _U1, typename _U2>
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static constexpr bool _MoveConstructiblePair()
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{
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return false;
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}
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template <typename _U1, typename _U2>
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static constexpr bool _ImplicitlyMoveConvertiblePair()
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{
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return false;
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}
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};
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#endif // lib concepts
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#endif // C++11
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#if __glibcxx_tuple_like // >= C++23
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template<typename _Tp>
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inline constexpr bool __is_tuple_v = false;
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template<typename... _Ts>
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inline constexpr bool __is_tuple_v<tuple<_Ts...>> = true;
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// TODO: Reuse __is_tuple_like from <type_traits>?
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template<typename _Tp>
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inline constexpr bool __is_tuple_like_v = false;
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template<typename... _Elements>
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inline constexpr bool __is_tuple_like_v<tuple<_Elements...>> = true;
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template<typename _T1, typename _T2>
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inline constexpr bool __is_tuple_like_v<pair<_T1, _T2>> = true;
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template<typename _Tp, size_t _Nm>
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inline constexpr bool __is_tuple_like_v<array<_Tp, _Nm>> = true;
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// __is_tuple_like_v<subrange> is defined in <bits/ranges_util.h>.
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template<typename _Tp>
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concept __tuple_like = __is_tuple_like_v<remove_cvref_t<_Tp>>;
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template<typename _Tp>
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concept __pair_like = __tuple_like<_Tp> && tuple_size_v<remove_cvref_t<_Tp>> == 2;
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template<typename _Tp, typename _Tuple>
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concept __eligible_tuple_like
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= __detail::__different_from<_Tp, _Tuple> && __tuple_like<_Tp>
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&& (tuple_size_v<remove_cvref_t<_Tp>> == tuple_size_v<_Tuple>)
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&& !ranges::__detail::__is_subrange<remove_cvref_t<_Tp>>;
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template<typename _Tp, typename _Pair>
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concept __eligible_pair_like
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= __detail::__different_from<_Tp, _Pair> && __pair_like<_Tp>
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&& !ranges::__detail::__is_subrange<remove_cvref_t<_Tp>>;
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#endif // C++23
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template<typename _U1, typename _U2> class __pair_base
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{
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#if __cplusplus >= 201103L && ! __cpp_lib_concepts
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template<typename _T1, typename _T2> friend struct pair;
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__pair_base() = default;
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~__pair_base() = default;
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__pair_base(const __pair_base&) = default;
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__pair_base& operator=(const __pair_base&) = delete;
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#endif // C++11
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};
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/// @endcond
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/**
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* @brief Struct holding two objects of arbitrary type.
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*
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* @tparam _T1 Type of first object.
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* @tparam _T2 Type of second object.
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*
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* <https://gcc.gnu.org/onlinedocs/libstdc++/manual/utilities.html>
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*
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* @headerfile utility
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*/
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template<typename _T1, typename _T2>
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struct pair
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: public __pair_base<_T1, _T2>
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{
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typedef _T1 first_type; ///< The type of the `first` member
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typedef _T2 second_type; ///< The type of the `second` member
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_T1 first; ///< The first member
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_T2 second; ///< The second member
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#if __cplusplus >= 201103L
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constexpr pair(const pair&) = default; ///< Copy constructor
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constexpr pair(pair&&) = default; ///< Move constructor
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template<typename... _Args1, typename... _Args2>
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_GLIBCXX20_CONSTEXPR
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pair(piecewise_construct_t, tuple<_Args1...>, tuple<_Args2...>);
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/// Swap the first members and then the second members.
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_GLIBCXX20_CONSTEXPR void
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swap(pair& __p)
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noexcept(__and_<__is_nothrow_swappable<_T1>,
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__is_nothrow_swappable<_T2>>::value)
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{
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using std::swap;
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swap(first, __p.first);
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swap(second, __p.second);
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}
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#if __glibcxx_ranges_zip // >= C++23
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// As an extension, we constrain the const swap member function in order
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// to continue accepting explicit instantiation of pairs whose elements
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// are not all const swappable. Without this constraint, such an
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// explicit instantiation would also instantiate the ill-formed body of
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// this function and yield a hard error. This constraint shouldn't
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// affect the behavior of valid programs.
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constexpr void
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swap(const pair& __p) const
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noexcept(__and_v<__is_nothrow_swappable<const _T1>,
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__is_nothrow_swappable<const _T2>>)
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requires is_swappable_v<const _T1> && is_swappable_v<const _T2>
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{
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using std::swap;
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swap(first, __p.first);
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swap(second, __p.second);
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}
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#endif // C++23
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private:
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template<typename... _Args1, size_t... _Indexes1,
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typename... _Args2, size_t... _Indexes2>
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_GLIBCXX20_CONSTEXPR
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pair(tuple<_Args1...>&, tuple<_Args2...>&,
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_Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>);
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public:
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#if __cpp_lib_concepts
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// C++20 implementation using concepts, explicit(bool), fully constexpr.
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/// Default constructor
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constexpr
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explicit(__not_<__and_<__is_implicitly_default_constructible<_T1>,
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__is_implicitly_default_constructible<_T2>>>())
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pair()
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requires is_default_constructible_v<_T1>
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&& is_default_constructible_v<_T2>
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: first(), second()
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{ }
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private:
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/// @cond undocumented
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template<typename _U1, typename _U2>
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static constexpr bool
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_S_constructible()
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{
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if constexpr (is_constructible_v<_T1, _U1>)
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return is_constructible_v<_T2, _U2>;
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return false;
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}
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template<typename _U1, typename _U2>
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static constexpr bool
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_S_nothrow_constructible()
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{
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if constexpr (is_nothrow_constructible_v<_T1, _U1>)
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return is_nothrow_constructible_v<_T2, _U2>;
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return false;
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}
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template<typename _U1, typename _U2>
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static constexpr bool
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_S_convertible()
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{
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if constexpr (is_convertible_v<_U1, _T1>)
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return is_convertible_v<_U2, _T2>;
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return false;
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}
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// True if construction from _U1 and _U2 would create a dangling ref.
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template<typename _U1, typename _U2>
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static constexpr bool
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_S_dangles()
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{
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#if __has_builtin(__reference_constructs_from_temporary)
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if constexpr (__reference_constructs_from_temporary(_T1, _U1&&))
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return true;
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else
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return __reference_constructs_from_temporary(_T2, _U2&&);
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#else
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return false;
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#endif
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}
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#if __glibcxx_tuple_like // >= C++23
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template<typename _UPair>
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static constexpr bool
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_S_constructible_from_pair_like()
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{
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return _S_constructible<decltype(std::get<0>(std::declval<_UPair>())),
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decltype(std::get<1>(std::declval<_UPair>()))>();
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}
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template<typename _UPair>
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static constexpr bool
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_S_convertible_from_pair_like()
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{
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return _S_convertible<decltype(std::get<0>(std::declval<_UPair>())),
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decltype(std::get<1>(std::declval<_UPair>()))>();
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}
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template<typename _UPair>
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static constexpr bool
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_S_dangles_from_pair_like()
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{
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return _S_dangles<decltype(std::get<0>(std::declval<_UPair>())),
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decltype(std::get<1>(std::declval<_UPair>()))>();
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}
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#endif // C++23
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/// @endcond
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public:
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/// Constructor accepting lvalues of `first_type` and `second_type`
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constexpr explicit(!_S_convertible<const _T1&, const _T2&>())
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pair(const _T1& __x, const _T2& __y)
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noexcept(_S_nothrow_constructible<const _T1&, const _T2&>())
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requires (_S_constructible<const _T1&, const _T2&>())
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: first(__x), second(__y)
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{ }
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/// Constructor accepting two values of arbitrary types
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#if __cplusplus > 202002L
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template<typename _U1 = _T1, typename _U2 = _T2>
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#else
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template<typename _U1, typename _U2>
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#endif
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requires (_S_constructible<_U1, _U2>()) && (!_S_dangles<_U1, _U2>())
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constexpr explicit(!_S_convertible<_U1, _U2>())
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pair(_U1&& __x, _U2&& __y)
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noexcept(_S_nothrow_constructible<_U1, _U2>())
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|
: first(std::forward<_U1>(__x)), second(std::forward<_U2>(__y))
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{ }
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|
#if __cplusplus > 202002L
|
|
template<typename _U1 = _T1, typename _U2 = _T2>
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|
#else
|
|
template<typename _U1, typename _U2>
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|
#endif
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requires (_S_constructible<_U1, _U2>()) && (_S_dangles<_U1, _U2>())
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constexpr explicit(!_S_convertible<_U1, _U2>())
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pair(_U1&&, _U2&&) = delete;
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/// Converting constructor from a const `pair<U1, U2>` lvalue
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template<typename _U1, typename _U2>
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requires (_S_constructible<const _U1&, const _U2&>())
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&& (!_S_dangles<_U1, _U2>())
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constexpr explicit(!_S_convertible<const _U1&, const _U2&>())
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pair(const pair<_U1, _U2>& __p)
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noexcept(_S_nothrow_constructible<const _U1&, const _U2&>())
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: first(__p.first), second(__p.second)
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{ }
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template<typename _U1, typename _U2>
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requires (_S_constructible<const _U1&, const _U2&>())
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&& (_S_dangles<const _U1&, const _U2&>())
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constexpr explicit(!_S_convertible<const _U1&, const _U2&>())
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pair(const pair<_U1, _U2>&) = delete;
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/// Converting constructor from a non-const `pair<U1, U2>` rvalue
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|
template<typename _U1, typename _U2>
|
|
requires (_S_constructible<_U1, _U2>()) && (!_S_dangles<_U1, _U2>())
|
|
constexpr explicit(!_S_convertible<_U1, _U2>())
|
|
pair(pair<_U1, _U2>&& __p)
|
|
noexcept(_S_nothrow_constructible<_U1, _U2>())
|
|
: first(std::forward<_U1>(__p.first)),
|
|
second(std::forward<_U2>(__p.second))
|
|
{ }
|
|
|
|
template<typename _U1, typename _U2>
|
|
requires (_S_constructible<_U1, _U2>()) && (_S_dangles<_U1, _U2>())
|
|
constexpr explicit(!_S_convertible<_U1, _U2>())
|
|
pair(pair<_U1, _U2>&&) = delete;
|
|
|
|
#if __glibcxx_ranges_zip // >= C++23
|
|
/// Converting constructor from a non-const `pair<U1, U2>` lvalue
|
|
template<typename _U1, typename _U2>
|
|
requires (_S_constructible<_U1&, _U2&>()) && (!_S_dangles<_U1&, _U2&>())
|
|
constexpr explicit(!_S_convertible<_U1&, _U2&>())
|
|
pair(pair<_U1, _U2>& __p)
|
|
noexcept(_S_nothrow_constructible<_U1&, _U2&>())
|
|
: first(__p.first), second(__p.second)
|
|
{ }
|
|
|
|
template<typename _U1, typename _U2>
|
|
requires (_S_constructible<_U1&, _U2&>()) && (_S_dangles<_U1&, _U2&>())
|
|
constexpr explicit(!_S_convertible<_U1&, _U2&>())
|
|
pair(pair<_U1, _U2>&) = delete;
|
|
|
|
/// Converting constructor from a const `pair<U1, U2>` rvalue
|
|
template<typename _U1, typename _U2>
|
|
requires (_S_constructible<const _U1, const _U2>())
|
|
&& (!_S_dangles<const _U1, const _U2>())
|
|
constexpr explicit(!_S_convertible<const _U1, const _U2>())
|
|
pair(const pair<_U1, _U2>&& __p)
|
|
noexcept(_S_nothrow_constructible<const _U1, const _U2>())
|
|
: first(std::forward<const _U1>(__p.first)),
|
|
second(std::forward<const _U2>(__p.second))
|
|
{ }
|
|
|
|
template<typename _U1, typename _U2>
|
|
requires (_S_constructible<const _U1, const _U2>())
|
|
&& (_S_dangles<const _U1, const _U2>())
|
|
constexpr explicit(!_S_convertible<const _U1, const _U2>())
|
|
pair(const pair<_U1, _U2>&&) = delete;
|
|
#endif // C++23
|
|
|
|
#if __glibcxx_tuple_like // >= C++23
|
|
template<__eligible_pair_like<pair> _UPair>
|
|
requires (_S_constructible_from_pair_like<_UPair>())
|
|
&& (!_S_dangles_from_pair_like<_UPair>())
|
|
constexpr explicit(!_S_convertible_from_pair_like<_UPair>())
|
|
pair(_UPair&& __p)
|
|
: first(std::get<0>(std::forward<_UPair>(__p))),
|
|
second(std::get<1>(std::forward<_UPair>(__p)))
|
|
{ }
|
|
|
|
template<__eligible_pair_like<pair> _UPair>
|
|
requires (_S_constructible_from_pair_like<_UPair>())
|
|
&& (_S_dangles_from_pair_like<_UPair>())
|
|
constexpr explicit(!_S_convertible_from_pair_like<_UPair>())
|
|
pair(_UPair&&) = delete;
|
|
#endif // C++23
|
|
|
|
private:
|
|
/// @cond undocumented
|
|
template<typename _U1, typename _U2>
|
|
static constexpr bool
|
|
_S_assignable()
|
|
{
|
|
if constexpr (is_assignable_v<_T1&, _U1>)
|
|
return is_assignable_v<_T2&, _U2>;
|
|
return false;
|
|
}
|
|
|
|
template<typename _U1, typename _U2>
|
|
static constexpr bool
|
|
_S_const_assignable()
|
|
{
|
|
if constexpr (is_assignable_v<const _T1&, _U1>)
|
|
return is_assignable_v<const _T2&, _U2>;
|
|
return false;
|
|
}
|
|
|
|
template<typename _U1, typename _U2>
|
|
static constexpr bool
|
|
_S_nothrow_assignable()
|
|
{
|
|
if constexpr (is_nothrow_assignable_v<_T1&, _U1>)
|
|
return is_nothrow_assignable_v<_T2&, _U2>;
|
|
return false;
|
|
}
|
|
|
|
#if __glibcxx_tuple_like // >= C++23
|
|
template<typename _UPair>
|
|
static constexpr bool
|
|
_S_assignable_from_tuple_like()
|
|
{
|
|
return _S_assignable<decltype(std::get<0>(std::declval<_UPair>())),
|
|
decltype(std::get<1>(std::declval<_UPair>()))>();
|
|
}
|
|
|
|
template<typename _UPair>
|
|
static constexpr bool
|
|
_S_const_assignable_from_tuple_like()
|
|
{
|
|
return _S_const_assignable<decltype(std::get<0>(std::declval<_UPair>())),
|
|
decltype(std::get<1>(std::declval<_UPair>()))>();
|
|
}
|
|
#endif // C++23
|
|
/// @endcond
|
|
|
|
public:
|
|
|
|
pair& operator=(const pair&) = delete;
|
|
|
|
/// Copy assignment operator
|
|
constexpr pair&
|
|
operator=(const pair& __p)
|
|
noexcept(_S_nothrow_assignable<const _T1&, const _T2&>())
|
|
requires (_S_assignable<const _T1&, const _T2&>())
|
|
{
|
|
first = __p.first;
|
|
second = __p.second;
|
|
return *this;
|
|
}
|
|
|
|
/// Move assignment operator
|
|
constexpr pair&
|
|
operator=(pair&& __p)
|
|
noexcept(_S_nothrow_assignable<_T1, _T2>())
|
|
requires (_S_assignable<_T1, _T2>())
|
|
{
|
|
first = std::forward<first_type>(__p.first);
|
|
second = std::forward<second_type>(__p.second);
|
|
return *this;
|
|
}
|
|
|
|
/// Converting assignment from a const `pair<U1, U2>` lvalue
|
|
template<typename _U1, typename _U2>
|
|
constexpr pair&
|
|
operator=(const pair<_U1, _U2>& __p)
|
|
noexcept(_S_nothrow_assignable<const _U1&, const _U2&>())
|
|
requires (_S_assignable<const _U1&, const _U2&>())
|
|
{
|
|
first = __p.first;
|
|
second = __p.second;
|
|
return *this;
|
|
}
|
|
|
|
/// Converting assignment from a non-const `pair<U1, U2>` rvalue
|
|
template<typename _U1, typename _U2>
|
|
constexpr pair&
|
|
operator=(pair<_U1, _U2>&& __p)
|
|
noexcept(_S_nothrow_assignable<_U1, _U2>())
|
|
requires (_S_assignable<_U1, _U2>())
|
|
{
|
|
first = std::forward<_U1>(__p.first);
|
|
second = std::forward<_U2>(__p.second);
|
|
return *this;
|
|
}
|
|
|
|
#if __glibcxx_ranges_zip // >= C++23
|
|
/// Copy assignment operator (const)
|
|
constexpr const pair&
|
|
operator=(const pair& __p) const
|
|
requires (_S_const_assignable<const first_type&, const second_type&>())
|
|
{
|
|
first = __p.first;
|
|
second = __p.second;
|
|
return *this;
|
|
}
|
|
|
|
/// Move assignment operator (const)
|
|
constexpr const pair&
|
|
operator=(pair&& __p) const
|
|
requires (_S_const_assignable<first_type, second_type>())
|
|
{
|
|
first = std::forward<first_type>(__p.first);
|
|
second = std::forward<second_type>(__p.second);
|
|
return *this;
|
|
}
|
|
|
|
/// Converting assignment from a const `pair<U1, U2>` lvalue
|
|
template<typename _U1, typename _U2>
|
|
constexpr const pair&
|
|
operator=(const pair<_U1, _U2>& __p) const
|
|
requires (_S_const_assignable<const _U1&, const _U2&>())
|
|
{
|
|
first = __p.first;
|
|
second = __p.second;
|
|
return *this;
|
|
}
|
|
|
|
/// Converting assignment from a non-const `pair<U1, U2>` rvalue
|
|
template<typename _U1, typename _U2>
|
|
constexpr const pair&
|
|
operator=(pair<_U1, _U2>&& __p) const
|
|
requires (_S_const_assignable<_U1, _U2>())
|
|
{
|
|
first = std::forward<_U1>(__p.first);
|
|
second = std::forward<_U2>(__p.second);
|
|
return *this;
|
|
}
|
|
#endif // C++23
|
|
|
|
#if __glibcxx_tuple_like // >= C++23
|
|
template<__eligible_pair_like<pair> _UPair>
|
|
requires (_S_assignable_from_tuple_like<_UPair>())
|
|
constexpr pair&
|
|
operator=(_UPair&& __p)
|
|
{
|
|
first = std::get<0>(std::forward<_UPair>(__p));
|
|
second = std::get<1>(std::forward<_UPair>(__p));
|
|
return *this;
|
|
}
|
|
|
|
template<__eligible_pair_like<pair> _UPair>
|
|
requires (_S_const_assignable_from_tuple_like<_UPair>())
|
|
constexpr const pair&
|
|
operator=(_UPair&& __p) const
|
|
{
|
|
first = std::get<0>(std::forward<_UPair>(__p));
|
|
second = std::get<1>(std::forward<_UPair>(__p));
|
|
return *this;
|
|
}
|
|
#endif // C++23
|
|
|
|
#else // !__cpp_lib_concepts
|
|
// C++11/14/17 implementation using enable_if, partially constexpr.
|
|
|
|
/// @cond undocumented
|
|
// Error if construction from _U1 and _U2 would create a dangling ref.
|
|
#if __has_builtin(__reference_constructs_from_temporary) \
|
|
&& defined _GLIBCXX_DEBUG
|
|
# define __glibcxx_no_dangling_refs(_U1, _U2) \
|
|
static_assert(!__reference_constructs_from_temporary(_T1, _U1) \
|
|
&& !__reference_constructs_from_temporary(_T2, _U2), \
|
|
"std::pair constructor creates a dangling reference")
|
|
#else
|
|
# define __glibcxx_no_dangling_refs(_U1, _U2)
|
|
#endif
|
|
/// @endcond
|
|
|
|
/** The default constructor creates @c first and @c second using their
|
|
* respective default constructors. */
|
|
template <typename _U1 = _T1,
|
|
typename _U2 = _T2,
|
|
typename enable_if<__and_<
|
|
__is_implicitly_default_constructible<_U1>,
|
|
__is_implicitly_default_constructible<_U2>>
|
|
::value, bool>::type = true>
|
|
constexpr pair()
|
|
: first(), second() { }
|
|
|
|
template <typename _U1 = _T1,
|
|
typename _U2 = _T2,
|
|
typename enable_if<__and_<
|
|
is_default_constructible<_U1>,
|
|
is_default_constructible<_U2>,
|
|
__not_<
|
|
__and_<__is_implicitly_default_constructible<_U1>,
|
|
__is_implicitly_default_constructible<_U2>>>>
|
|
::value, bool>::type = false>
|
|
explicit constexpr pair()
|
|
: first(), second() { }
|
|
|
|
// Shortcut for constraining the templates that don't take pairs.
|
|
/// @cond undocumented
|
|
using _PCCP = _PCC<true, _T1, _T2>;
|
|
/// @endcond
|
|
|
|
/// Construct from two const lvalues, allowing implicit conversions.
|
|
template<typename _U1 = _T1, typename _U2=_T2, typename
|
|
enable_if<_PCCP::template
|
|
_ConstructiblePair<_U1, _U2>()
|
|
&& _PCCP::template
|
|
_ImplicitlyConvertiblePair<_U1, _U2>(),
|
|
bool>::type=true>
|
|
constexpr pair(const _T1& __a, const _T2& __b)
|
|
: first(__a), second(__b) { }
|
|
|
|
/// Construct from two const lvalues, disallowing implicit conversions.
|
|
template<typename _U1 = _T1, typename _U2=_T2, typename
|
|
enable_if<_PCCP::template
|
|
_ConstructiblePair<_U1, _U2>()
|
|
&& !_PCCP::template
|
|
_ImplicitlyConvertiblePair<_U1, _U2>(),
|
|
bool>::type=false>
|
|
explicit constexpr pair(const _T1& __a, const _T2& __b)
|
|
: first(__a), second(__b) { }
|
|
|
|
// Shortcut for constraining the templates that take pairs.
|
|
/// @cond undocumented
|
|
template <typename _U1, typename _U2>
|
|
using _PCCFP = _PCC<!is_same<_T1, _U1>::value
|
|
|| !is_same<_T2, _U2>::value,
|
|
_T1, _T2>;
|
|
/// @endcond
|
|
|
|
template<typename _U1, typename _U2, typename
|
|
enable_if<_PCCFP<_U1, _U2>::template
|
|
_ConstructiblePair<_U1, _U2>()
|
|
&& _PCCFP<_U1, _U2>::template
|
|
_ImplicitlyConvertiblePair<_U1, _U2>(),
|
|
bool>::type=true>
|
|
constexpr pair(const pair<_U1, _U2>& __p)
|
|
: first(__p.first), second(__p.second)
|
|
{ __glibcxx_no_dangling_refs(const _U1&, const _U2&); }
|
|
|
|
template<typename _U1, typename _U2, typename
|
|
enable_if<_PCCFP<_U1, _U2>::template
|
|
_ConstructiblePair<_U1, _U2>()
|
|
&& !_PCCFP<_U1, _U2>::template
|
|
_ImplicitlyConvertiblePair<_U1, _U2>(),
|
|
bool>::type=false>
|
|
explicit constexpr pair(const pair<_U1, _U2>& __p)
|
|
: first(__p.first), second(__p.second)
|
|
{ __glibcxx_no_dangling_refs(const _U1&, const _U2&); }
|
|
|
|
#if _GLIBCXX_USE_DEPRECATED
|
|
#if defined(__DEPRECATED)
|
|
# define _GLIBCXX_DEPRECATED_PAIR_CTOR \
|
|
__attribute__ ((__deprecated__ ("use 'nullptr' instead of '0' to " \
|
|
"initialize std::pair of move-only " \
|
|
"type and pointer")))
|
|
#else
|
|
# define _GLIBCXX_DEPRECATED_PAIR_CTOR
|
|
#endif
|
|
|
|
private:
|
|
/// @cond undocumented
|
|
|
|
// A type which can be constructed from literal zero, but not nullptr
|
|
struct __zero_as_null_pointer_constant
|
|
{
|
|
__zero_as_null_pointer_constant(int __zero_as_null_pointer_constant::*)
|
|
{ }
|
|
template<typename _Tp,
|
|
typename = __enable_if_t<is_null_pointer<_Tp>::value>>
|
|
__zero_as_null_pointer_constant(_Tp) = delete;
|
|
};
|
|
/// @endcond
|
|
public:
|
|
|
|
// Deprecated extensions to DR 811.
|
|
// These allow construction from an rvalue and a literal zero,
|
|
// in cases where the standard says the zero should be deduced as int
|
|
template<typename _U1,
|
|
__enable_if_t<__and_<__not_<is_reference<_U1>>,
|
|
is_pointer<_T2>,
|
|
is_constructible<_T1, _U1>,
|
|
__not_<is_constructible<_T1, const _U1&>>,
|
|
is_convertible<_U1, _T1>>::value,
|
|
bool> = true>
|
|
_GLIBCXX_DEPRECATED_PAIR_CTOR
|
|
constexpr
|
|
pair(_U1&& __x, __zero_as_null_pointer_constant, ...)
|
|
: first(std::forward<_U1>(__x)), second(nullptr)
|
|
{ __glibcxx_no_dangling_refs(_U1&&, std::nullptr_t); }
|
|
|
|
template<typename _U1,
|
|
__enable_if_t<__and_<__not_<is_reference<_U1>>,
|
|
is_pointer<_T2>,
|
|
is_constructible<_T1, _U1>,
|
|
__not_<is_constructible<_T1, const _U1&>>,
|
|
__not_<is_convertible<_U1, _T1>>>::value,
|
|
bool> = false>
|
|
_GLIBCXX_DEPRECATED_PAIR_CTOR
|
|
explicit constexpr
|
|
pair(_U1&& __x, __zero_as_null_pointer_constant, ...)
|
|
: first(std::forward<_U1>(__x)), second(nullptr)
|
|
{ __glibcxx_no_dangling_refs(_U1&&, std::nullptr_t); }
|
|
|
|
template<typename _U2,
|
|
__enable_if_t<__and_<is_pointer<_T1>,
|
|
__not_<is_reference<_U2>>,
|
|
is_constructible<_T2, _U2>,
|
|
__not_<is_constructible<_T2, const _U2&>>,
|
|
is_convertible<_U2, _T2>>::value,
|
|
bool> = true>
|
|
_GLIBCXX_DEPRECATED_PAIR_CTOR
|
|
constexpr
|
|
pair(__zero_as_null_pointer_constant, _U2&& __y, ...)
|
|
: first(nullptr), second(std::forward<_U2>(__y))
|
|
{ __glibcxx_no_dangling_refs(std::nullptr_t, _U2&&); }
|
|
|
|
template<typename _U2,
|
|
__enable_if_t<__and_<is_pointer<_T1>,
|
|
__not_<is_reference<_U2>>,
|
|
is_constructible<_T2, _U2>,
|
|
__not_<is_constructible<_T2, const _U2&>>,
|
|
__not_<is_convertible<_U2, _T2>>>::value,
|
|
bool> = false>
|
|
_GLIBCXX_DEPRECATED_PAIR_CTOR
|
|
explicit constexpr
|
|
pair(__zero_as_null_pointer_constant, _U2&& __y, ...)
|
|
: first(nullptr), second(std::forward<_U2>(__y))
|
|
{ __glibcxx_no_dangling_refs(std::nullptr_t, _U2&&); }
|
|
#undef _GLIBCXX_DEPRECATED_PAIR_CTOR
|
|
#endif
|
|
|
|
template<typename _U1, typename _U2, typename
|
|
enable_if<_PCCP::template
|
|
_MoveConstructiblePair<_U1, _U2>()
|
|
&& _PCCP::template
|
|
_ImplicitlyMoveConvertiblePair<_U1, _U2>(),
|
|
bool>::type=true>
|
|
constexpr pair(_U1&& __x, _U2&& __y)
|
|
: first(std::forward<_U1>(__x)), second(std::forward<_U2>(__y))
|
|
{ __glibcxx_no_dangling_refs(_U1&&, _U2&&); }
|
|
|
|
template<typename _U1, typename _U2, typename
|
|
enable_if<_PCCP::template
|
|
_MoveConstructiblePair<_U1, _U2>()
|
|
&& !_PCCP::template
|
|
_ImplicitlyMoveConvertiblePair<_U1, _U2>(),
|
|
bool>::type=false>
|
|
explicit constexpr pair(_U1&& __x, _U2&& __y)
|
|
: first(std::forward<_U1>(__x)), second(std::forward<_U2>(__y))
|
|
{ __glibcxx_no_dangling_refs(_U1&&, _U2&&); }
|
|
|
|
|
|
template<typename _U1, typename _U2, typename
|
|
enable_if<_PCCFP<_U1, _U2>::template
|
|
_MoveConstructiblePair<_U1, _U2>()
|
|
&& _PCCFP<_U1, _U2>::template
|
|
_ImplicitlyMoveConvertiblePair<_U1, _U2>(),
|
|
bool>::type=true>
|
|
constexpr pair(pair<_U1, _U2>&& __p)
|
|
: first(std::forward<_U1>(__p.first)),
|
|
second(std::forward<_U2>(__p.second))
|
|
{ __glibcxx_no_dangling_refs(_U1&&, _U2&&); }
|
|
|
|
template<typename _U1, typename _U2, typename
|
|
enable_if<_PCCFP<_U1, _U2>::template
|
|
_MoveConstructiblePair<_U1, _U2>()
|
|
&& !_PCCFP<_U1, _U2>::template
|
|
_ImplicitlyMoveConvertiblePair<_U1, _U2>(),
|
|
bool>::type=false>
|
|
explicit constexpr pair(pair<_U1, _U2>&& __p)
|
|
: first(std::forward<_U1>(__p.first)),
|
|
second(std::forward<_U2>(__p.second))
|
|
{ __glibcxx_no_dangling_refs(_U1&&, _U2&&); }
|
|
|
|
#undef __glibcxx_no_dangling_refs
|
|
|
|
pair&
|
|
operator=(__conditional_t<__and_<is_copy_assignable<_T1>,
|
|
is_copy_assignable<_T2>>::value,
|
|
const pair&, const __nonesuch&> __p)
|
|
{
|
|
first = __p.first;
|
|
second = __p.second;
|
|
return *this;
|
|
}
|
|
|
|
pair&
|
|
operator=(__conditional_t<__and_<is_move_assignable<_T1>,
|
|
is_move_assignable<_T2>>::value,
|
|
pair&&, __nonesuch&&> __p)
|
|
noexcept(__and_<is_nothrow_move_assignable<_T1>,
|
|
is_nothrow_move_assignable<_T2>>::value)
|
|
{
|
|
first = std::forward<first_type>(__p.first);
|
|
second = std::forward<second_type>(__p.second);
|
|
return *this;
|
|
}
|
|
|
|
template<typename _U1, typename _U2>
|
|
typename enable_if<__and_<is_assignable<_T1&, const _U1&>,
|
|
is_assignable<_T2&, const _U2&>>::value,
|
|
pair&>::type
|
|
operator=(const pair<_U1, _U2>& __p)
|
|
{
|
|
first = __p.first;
|
|
second = __p.second;
|
|
return *this;
|
|
}
|
|
|
|
template<typename _U1, typename _U2>
|
|
typename enable_if<__and_<is_assignable<_T1&, _U1&&>,
|
|
is_assignable<_T2&, _U2&&>>::value,
|
|
pair&>::type
|
|
operator=(pair<_U1, _U2>&& __p)
|
|
{
|
|
first = std::forward<_U1>(__p.first);
|
|
second = std::forward<_U2>(__p.second);
|
|
return *this;
|
|
}
|
|
#endif // lib concepts
|
|
#else
|
|
// C++03 implementation
|
|
|
|
// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 265. std::pair::pair() effects overly restrictive
|
|
/** The default constructor creates @c first and @c second using their
|
|
* respective default constructors. */
|
|
pair() : first(), second() { }
|
|
|
|
/// Two objects may be passed to a `pair` constructor to be copied.
|
|
pair(const _T1& __a, const _T2& __b)
|
|
: first(__a), second(__b) { }
|
|
|
|
/// Templated constructor to convert from other pairs.
|
|
template<typename _U1, typename _U2>
|
|
pair(const pair<_U1, _U2>& __p)
|
|
: first(__p.first), second(__p.second)
|
|
{
|
|
#if __has_builtin(__reference_constructs_from_temporary)
|
|
#pragma GCC diagnostic push
|
|
#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
|
|
typedef int _DanglingCheck1[
|
|
__reference_constructs_from_temporary(_T1, const _U1&) ? -1 : 1
|
|
];
|
|
typedef int _DanglingCheck2[
|
|
__reference_constructs_from_temporary(_T2, const _U2&) ? -1 : 1
|
|
];
|
|
#pragma GCC diagnostic pop
|
|
#endif
|
|
}
|
|
#endif // C++11
|
|
};
|
|
|
|
/// @relates pair @{
|
|
|
|
#if __cpp_deduction_guides >= 201606
|
|
template<typename _T1, typename _T2> pair(_T1, _T2) -> pair<_T1, _T2>;
|
|
#endif
|
|
|
|
#if __cpp_lib_three_way_comparison && __cpp_lib_concepts
|
|
// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 3865. Sorting a range of pairs
|
|
|
|
/// Two pairs are equal iff their members are equal.
|
|
template<typename _T1, typename _T2, typename _U1, typename _U2>
|
|
inline _GLIBCXX_CONSTEXPR bool
|
|
operator==(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y)
|
|
{ return __x.first == __y.first && __x.second == __y.second; }
|
|
|
|
/** Defines a lexicographical order for pairs.
|
|
*
|
|
* For two pairs of comparable types, `P` is ordered before `Q` if
|
|
* `P.first` is less than `Q.first`, or if `P.first` and `Q.first`
|
|
* are equivalent (neither is less than the other) and `P.second` is
|
|
* less than `Q.second`.
|
|
*/
|
|
template<typename _T1, typename _T2, typename _U1, typename _U2>
|
|
constexpr common_comparison_category_t<__detail::__synth3way_t<_T1, _U1>,
|
|
__detail::__synth3way_t<_T2, _U2>>
|
|
operator<=>(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y)
|
|
{
|
|
if (auto __c = __detail::__synth3way(__x.first, __y.first); __c != 0)
|
|
return __c;
|
|
return __detail::__synth3way(__x.second, __y.second);
|
|
}
|
|
#else
|
|
/// Two pairs of the same type are equal iff their members are equal.
|
|
template<typename _T1, typename _T2>
|
|
inline _GLIBCXX_CONSTEXPR bool
|
|
operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
|
|
{ return __x.first == __y.first && __x.second == __y.second; }
|
|
|
|
/** Defines a lexicographical order for pairs.
|
|
*
|
|
* For two pairs of the same type, `P` is ordered before `Q` if
|
|
* `P.first` is less than `Q.first`, or if `P.first` and `Q.first`
|
|
* are equivalent (neither is less than the other) and `P.second` is less
|
|
* than `Q.second`.
|
|
*/
|
|
template<typename _T1, typename _T2>
|
|
inline _GLIBCXX_CONSTEXPR bool
|
|
operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
|
|
{ return __x.first < __y.first
|
|
|| (!(__y.first < __x.first) && __x.second < __y.second); }
|
|
|
|
/// Uses @c operator== to find the result.
|
|
template<typename _T1, typename _T2>
|
|
inline _GLIBCXX_CONSTEXPR bool
|
|
operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
|
|
{ return !(__x == __y); }
|
|
|
|
/// Uses @c operator< to find the result.
|
|
template<typename _T1, typename _T2>
|
|
inline _GLIBCXX_CONSTEXPR bool
|
|
operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
|
|
{ return __y < __x; }
|
|
|
|
/// Uses @c operator< to find the result.
|
|
template<typename _T1, typename _T2>
|
|
inline _GLIBCXX_CONSTEXPR bool
|
|
operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
|
|
{ return !(__y < __x); }
|
|
|
|
/// Uses @c operator< to find the result.
|
|
template<typename _T1, typename _T2>
|
|
inline _GLIBCXX_CONSTEXPR bool
|
|
operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
|
|
{ return !(__x < __y); }
|
|
#endif // !(three_way_comparison && concepts)
|
|
|
|
#if __cplusplus >= 201103L
|
|
/** Swap overload for pairs. Calls std::pair::swap().
|
|
*
|
|
* @note This std::swap overload is not declared in C++03 mode,
|
|
* which has performance implications, e.g. see https://gcc.gnu.org/PR38466
|
|
*/
|
|
template<typename _T1, typename _T2>
|
|
_GLIBCXX20_CONSTEXPR inline
|
|
#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
|
|
// Constrained free swap overload, see p0185r1
|
|
typename enable_if<__and_<__is_swappable<_T1>,
|
|
__is_swappable<_T2>>::value>::type
|
|
#else
|
|
void
|
|
#endif
|
|
swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
|
|
noexcept(noexcept(__x.swap(__y)))
|
|
{ __x.swap(__y); }
|
|
|
|
#if __glibcxx_ranges_zip // >= C++23
|
|
template<typename _T1, typename _T2>
|
|
requires is_swappable_v<const _T1> && is_swappable_v<const _T2>
|
|
constexpr void
|
|
swap(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
|
|
noexcept(noexcept(__x.swap(__y)))
|
|
{ __x.swap(__y); }
|
|
#endif // C++23
|
|
|
|
#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
|
|
template<typename _T1, typename _T2>
|
|
typename enable_if<!__and_<__is_swappable<_T1>,
|
|
__is_swappable<_T2>>::value>::type
|
|
swap(pair<_T1, _T2>&, pair<_T1, _T2>&) = delete;
|
|
#endif
|
|
#endif // __cplusplus >= 201103L
|
|
|
|
/// @} relates pair
|
|
|
|
/**
|
|
* @brief A convenience wrapper for creating a pair from two objects.
|
|
* @param __x The first object.
|
|
* @param __y The second object.
|
|
* @return A newly-constructed pair<> object of the appropriate type.
|
|
*
|
|
* The C++98 standard says the objects are passed by reference-to-const,
|
|
* but C++03 says they are passed by value (this was LWG issue #181).
|
|
*
|
|
* Since C++11 they have been passed by forwarding reference and then
|
|
* forwarded to the new members of the pair. To create a pair with a
|
|
* member of reference type, pass a `reference_wrapper` to this function.
|
|
*/
|
|
// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 181. make_pair() unintended behavior
|
|
#if __cplusplus >= 201103L
|
|
// NB: DR 706.
|
|
template<typename _T1, typename _T2>
|
|
constexpr pair<typename __decay_and_strip<_T1>::__type,
|
|
typename __decay_and_strip<_T2>::__type>
|
|
make_pair(_T1&& __x, _T2&& __y)
|
|
{
|
|
typedef typename __decay_and_strip<_T1>::__type __ds_type1;
|
|
typedef typename __decay_and_strip<_T2>::__type __ds_type2;
|
|
typedef pair<__ds_type1, __ds_type2> __pair_type;
|
|
return __pair_type(std::forward<_T1>(__x), std::forward<_T2>(__y));
|
|
}
|
|
#else
|
|
template<typename _T1, typename _T2>
|
|
inline pair<_T1, _T2>
|
|
make_pair(_T1 __x, _T2 __y)
|
|
{ return pair<_T1, _T2>(__x, __y); }
|
|
#endif
|
|
|
|
/// @}
|
|
|
|
#if __cplusplus >= 201103L
|
|
// Various functions which give std::pair a tuple-like interface.
|
|
|
|
/// @cond undocumented
|
|
template<typename _T1, typename _T2>
|
|
struct __is_tuple_like_impl<pair<_T1, _T2>> : true_type
|
|
{ };
|
|
/// @endcond
|
|
|
|
/// Partial specialization for std::pair
|
|
template<class _Tp1, class _Tp2>
|
|
struct tuple_size<pair<_Tp1, _Tp2>>
|
|
: public integral_constant<size_t, 2> { };
|
|
|
|
/// Partial specialization for std::pair
|
|
template<class _Tp1, class _Tp2>
|
|
struct tuple_element<0, pair<_Tp1, _Tp2>>
|
|
{ typedef _Tp1 type; };
|
|
|
|
/// Partial specialization for std::pair
|
|
template<class _Tp1, class _Tp2>
|
|
struct tuple_element<1, pair<_Tp1, _Tp2>>
|
|
{ typedef _Tp2 type; };
|
|
|
|
// Forward declare the partial specialization for std::tuple
|
|
// to work around modules bug PR c++/113814.
|
|
template<size_t __i, typename... _Types>
|
|
struct tuple_element<__i, tuple<_Types...>>;
|
|
|
|
#if __cplusplus >= 201703L
|
|
template<typename _Tp1, typename _Tp2>
|
|
inline constexpr size_t tuple_size_v<pair<_Tp1, _Tp2>> = 2;
|
|
|
|
template<typename _Tp1, typename _Tp2>
|
|
inline constexpr size_t tuple_size_v<const pair<_Tp1, _Tp2>> = 2;
|
|
|
|
template<typename _Tp>
|
|
inline constexpr bool __is_pair = false;
|
|
|
|
template<typename _Tp, typename _Up>
|
|
inline constexpr bool __is_pair<pair<_Tp, _Up>> = true;
|
|
#endif
|
|
|
|
/// @cond undocumented
|
|
template<size_t _Int>
|
|
struct __pair_get;
|
|
|
|
template<>
|
|
struct __pair_get<0>
|
|
{
|
|
template<typename _Tp1, typename _Tp2>
|
|
static constexpr _Tp1&
|
|
__get(pair<_Tp1, _Tp2>& __pair) noexcept
|
|
{ return __pair.first; }
|
|
|
|
template<typename _Tp1, typename _Tp2>
|
|
static constexpr _Tp1&&
|
|
__move_get(pair<_Tp1, _Tp2>&& __pair) noexcept
|
|
{ return std::forward<_Tp1>(__pair.first); }
|
|
|
|
template<typename _Tp1, typename _Tp2>
|
|
static constexpr const _Tp1&
|
|
__const_get(const pair<_Tp1, _Tp2>& __pair) noexcept
|
|
{ return __pair.first; }
|
|
|
|
template<typename _Tp1, typename _Tp2>
|
|
static constexpr const _Tp1&&
|
|
__const_move_get(const pair<_Tp1, _Tp2>&& __pair) noexcept
|
|
{ return std::forward<const _Tp1>(__pair.first); }
|
|
};
|
|
|
|
template<>
|
|
struct __pair_get<1>
|
|
{
|
|
template<typename _Tp1, typename _Tp2>
|
|
static constexpr _Tp2&
|
|
__get(pair<_Tp1, _Tp2>& __pair) noexcept
|
|
{ return __pair.second; }
|
|
|
|
template<typename _Tp1, typename _Tp2>
|
|
static constexpr _Tp2&&
|
|
__move_get(pair<_Tp1, _Tp2>&& __pair) noexcept
|
|
{ return std::forward<_Tp2>(__pair.second); }
|
|
|
|
template<typename _Tp1, typename _Tp2>
|
|
static constexpr const _Tp2&
|
|
__const_get(const pair<_Tp1, _Tp2>& __pair) noexcept
|
|
{ return __pair.second; }
|
|
|
|
template<typename _Tp1, typename _Tp2>
|
|
static constexpr const _Tp2&&
|
|
__const_move_get(const pair<_Tp1, _Tp2>&& __pair) noexcept
|
|
{ return std::forward<const _Tp2>(__pair.second); }
|
|
};
|
|
/// @endcond
|
|
|
|
/** @{
|
|
* std::get overloads for accessing members of std::pair
|
|
*/
|
|
|
|
template<size_t _Int, class _Tp1, class _Tp2>
|
|
constexpr typename tuple_element<_Int, pair<_Tp1, _Tp2>>::type&
|
|
get(pair<_Tp1, _Tp2>& __in) noexcept
|
|
{ return __pair_get<_Int>::__get(__in); }
|
|
|
|
template<size_t _Int, class _Tp1, class _Tp2>
|
|
constexpr typename tuple_element<_Int, pair<_Tp1, _Tp2>>::type&&
|
|
get(pair<_Tp1, _Tp2>&& __in) noexcept
|
|
{ return __pair_get<_Int>::__move_get(std::move(__in)); }
|
|
|
|
template<size_t _Int, class _Tp1, class _Tp2>
|
|
constexpr const typename tuple_element<_Int, pair<_Tp1, _Tp2>>::type&
|
|
get(const pair<_Tp1, _Tp2>& __in) noexcept
|
|
{ return __pair_get<_Int>::__const_get(__in); }
|
|
|
|
template<size_t _Int, class _Tp1, class _Tp2>
|
|
constexpr const typename tuple_element<_Int, pair<_Tp1, _Tp2>>::type&&
|
|
get(const pair<_Tp1, _Tp2>&& __in) noexcept
|
|
{ return __pair_get<_Int>::__const_move_get(std::move(__in)); }
|
|
|
|
|
|
#ifdef __glibcxx_tuples_by_type // C++ >= 14
|
|
template <typename _Tp, typename _Up>
|
|
constexpr _Tp&
|
|
get(pair<_Tp, _Up>& __p) noexcept
|
|
{ return __p.first; }
|
|
|
|
template <typename _Tp, typename _Up>
|
|
constexpr const _Tp&
|
|
get(const pair<_Tp, _Up>& __p) noexcept
|
|
{ return __p.first; }
|
|
|
|
template <typename _Tp, typename _Up>
|
|
constexpr _Tp&&
|
|
get(pair<_Tp, _Up>&& __p) noexcept
|
|
{ return std::move(__p.first); }
|
|
|
|
template <typename _Tp, typename _Up>
|
|
constexpr const _Tp&&
|
|
get(const pair<_Tp, _Up>&& __p) noexcept
|
|
{ return std::move(__p.first); }
|
|
|
|
template <typename _Tp, typename _Up>
|
|
constexpr _Tp&
|
|
get(pair<_Up, _Tp>& __p) noexcept
|
|
{ return __p.second; }
|
|
|
|
template <typename _Tp, typename _Up>
|
|
constexpr const _Tp&
|
|
get(const pair<_Up, _Tp>& __p) noexcept
|
|
{ return __p.second; }
|
|
|
|
template <typename _Tp, typename _Up>
|
|
constexpr _Tp&&
|
|
get(pair<_Up, _Tp>&& __p) noexcept
|
|
{ return std::move(__p.second); }
|
|
|
|
template <typename _Tp, typename _Up>
|
|
constexpr const _Tp&&
|
|
get(const pair<_Up, _Tp>&& __p) noexcept
|
|
{ return std::move(__p.second); }
|
|
#endif // __glibcxx_tuples_by_type
|
|
|
|
|
|
#if __glibcxx_ranges_zip // >= C++23
|
|
template<typename _T1, typename _T2, typename _U1, typename _U2,
|
|
template<typename> class _TQual, template<typename> class _UQual>
|
|
requires requires { typename pair<common_reference_t<_TQual<_T1>, _UQual<_U1>>,
|
|
common_reference_t<_TQual<_T2>, _UQual<_U2>>>; }
|
|
struct basic_common_reference<pair<_T1, _T2>, pair<_U1, _U2>, _TQual, _UQual>
|
|
{
|
|
using type = pair<common_reference_t<_TQual<_T1>, _UQual<_U1>>,
|
|
common_reference_t<_TQual<_T2>, _UQual<_U2>>>;
|
|
};
|
|
|
|
template<typename _T1, typename _T2, typename _U1, typename _U2>
|
|
requires requires { typename pair<common_type_t<_T1, _U1>, common_type_t<_T2, _U2>>; }
|
|
struct common_type<pair<_T1, _T2>, pair<_U1, _U2>>
|
|
{ using type = pair<common_type_t<_T1, _U1>, common_type_t<_T2, _U2>>; };
|
|
#endif // C++23
|
|
|
|
/// @}
|
|
#endif // C++11
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace std
|
|
|
|
#endif /* _STL_PAIR_H */
|