// <tuple> -*- C++ -*- // Copyright (C) 2007-2020 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file include/tuple * This is a Standard C++ Library header. */ #ifndef _GLIBCXX_TUPLE #define _GLIBCXX_TUPLE 1 #pragma GCC system_header #if __cplusplus < 201103L # include <bits/c++0x_warning.h> #else #include <utility> #include <array> #include <bits/uses_allocator.h> #include <bits/invoke.h> #if __cplusplus > 201703L # include <compare> # define __cpp_lib_constexpr_tuple 201811L #endif namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /** * @addtogroup utilities * @{ */ template<typename... _Elements> class tuple; template<typename _Tp> struct __is_empty_non_tuple : is_empty<_Tp> { }; // Using EBO for elements that are tuples causes ambiguous base errors. template<typename _El0, typename... _El> struct __is_empty_non_tuple<tuple<_El0, _El...>> : false_type { }; // Use the Empty Base-class Optimization for empty, non-final types. template<typename _Tp> using __empty_not_final = typename conditional<__is_final(_Tp), false_type, __is_empty_non_tuple<_Tp>>::type; template<std::size_t _Idx, typename _Head, bool = __empty_not_final<_Head>::value> struct _Head_base; template<std::size_t _Idx, typename _Head> struct _Head_base<_Idx, _Head, true> : public _Head { constexpr _Head_base() : _Head() { } constexpr _Head_base(const _Head& __h) : _Head(__h) { } constexpr _Head_base(const _Head_base&) = default; constexpr _Head_base(_Head_base&&) = default; template<typename _UHead> constexpr _Head_base(_UHead&& __h) : _Head(std::forward<_UHead>(__h)) { } _Head_base(allocator_arg_t, __uses_alloc0) : _Head() { } template<typename _Alloc> _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a) : _Head(allocator_arg, *__a._M_a) { } template<typename _Alloc> _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a) : _Head(*__a._M_a) { } template<typename _UHead> _Head_base(__uses_alloc0, _UHead&& __uhead) : _Head(std::forward<_UHead>(__uhead)) { } template<typename _Alloc, typename _UHead> _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead) : _Head(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) { } template<typename _Alloc, typename _UHead> _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead) : _Head(std::forward<_UHead>(__uhead), *__a._M_a) { } static constexpr _Head& _M_head(_Head_base& __b) noexcept { return __b; } static constexpr const _Head& _M_head(const _Head_base& __b) noexcept { return __b; } }; template<std::size_t _Idx, typename _Head> struct _Head_base<_Idx, _Head, false> { constexpr _Head_base() : _M_head_impl() { } constexpr _Head_base(const _Head& __h) : _M_head_impl(__h) { } constexpr _Head_base(const _Head_base&) = default; constexpr _Head_base(_Head_base&&) = default; template<typename _UHead> constexpr _Head_base(_UHead&& __h) : _M_head_impl(std::forward<_UHead>(__h)) { } _GLIBCXX20_CONSTEXPR _Head_base(allocator_arg_t, __uses_alloc0) : _M_head_impl() { } template<typename _Alloc> _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a) : _M_head_impl(allocator_arg, *__a._M_a) { } template<typename _Alloc> _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a) : _M_head_impl(*__a._M_a) { } template<typename _UHead> _GLIBCXX20_CONSTEXPR _Head_base(__uses_alloc0, _UHead&& __uhead) : _M_head_impl(std::forward<_UHead>(__uhead)) { } template<typename _Alloc, typename _UHead> _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead) : _M_head_impl(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) { } template<typename _Alloc, typename _UHead> _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead) : _M_head_impl(std::forward<_UHead>(__uhead), *__a._M_a) { } static constexpr _Head& _M_head(_Head_base& __b) noexcept { return __b._M_head_impl; } static constexpr const _Head& _M_head(const _Head_base& __b) noexcept { return __b._M_head_impl; } _Head _M_head_impl; }; /** * Contains the actual implementation of the @c tuple template, stored * as a recursive inheritance hierarchy from the first element (most * derived class) to the last (least derived class). The @c Idx * parameter gives the 0-based index of the element stored at this * point in the hierarchy; we use it to implement a constant-time * get() operation. */ template<std::size_t _Idx, typename... _Elements> struct _Tuple_impl; /** * Recursive tuple implementation. Here we store the @c Head element * and derive from a @c Tuple_impl containing the remaining elements * (which contains the @c Tail). */ template<std::size_t _Idx, typename _Head, typename... _Tail> struct _Tuple_impl<_Idx, _Head, _Tail...> : public _Tuple_impl<_Idx + 1, _Tail...>, private _Head_base<_Idx, _Head> { template<std::size_t, typename...> friend class _Tuple_impl; typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited; typedef _Head_base<_Idx, _Head> _Base; static constexpr _Head& _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } static constexpr const _Head& _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } static constexpr _Inherited& _M_tail(_Tuple_impl& __t) noexcept { return __t; } static constexpr const _Inherited& _M_tail(const _Tuple_impl& __t) noexcept { return __t; } constexpr _Tuple_impl() : _Inherited(), _Base() { } explicit constexpr _Tuple_impl(const _Head& __head, const _Tail&... __tail) : _Inherited(__tail...), _Base(__head) { } template<typename _UHead, typename... _UTail, typename = typename enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type> explicit constexpr _Tuple_impl(_UHead&& __head, _UTail&&... __tail) : _Inherited(std::forward<_UTail>(__tail)...), _Base(std::forward<_UHead>(__head)) { } constexpr _Tuple_impl(const _Tuple_impl&) = default; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 2729. Missing SFINAE on std::pair::operator= _Tuple_impl& operator=(const _Tuple_impl&) = delete; constexpr _Tuple_impl(_Tuple_impl&& __in) noexcept(__and_<is_nothrow_move_constructible<_Head>, is_nothrow_move_constructible<_Inherited>>::value) : _Inherited(std::move(_M_tail(__in))), _Base(std::forward<_Head>(_M_head(__in))) { } template<typename... _UElements> constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in) : _Inherited(_Tuple_impl<_Idx, _UElements...>::_M_tail(__in)), _Base(_Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { } template<typename _UHead, typename... _UTails> constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in) : _Inherited(std::move (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))), _Base(std::forward<_UHead> (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a) : _Inherited(__tag, __a), _Base(__tag, __use_alloc<_Head>(__a)) { } template<typename _Alloc> _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, const _Head& __head, const _Tail&... __tail) : _Inherited(__tag, __a, __tail...), _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { } template<typename _Alloc, typename _UHead, typename... _UTail, typename = typename enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, _UHead&& __head, _UTail&&... __tail) : _Inherited(__tag, __a, std::forward<_UTail>(__tail)...), _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), std::forward<_UHead>(__head)) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, const _Tuple_impl& __in) : _Inherited(__tag, __a, _M_tail(__in)), _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, _Tuple_impl&& __in) : _Inherited(__tag, __a, std::move(_M_tail(__in))), _Base(__use_alloc<_Head, _Alloc, _Head>(__a), std::forward<_Head>(_M_head(__in))) { } template<typename _Alloc, typename _UHead, typename... _UTails> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, const _Tuple_impl<_Idx, _UHead, _UTails...>& __in) : _Inherited(__tag, __a, _Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in)), _Base(__use_alloc<_Head, _Alloc, const _UHead&>(__a), _Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in)) { } template<typename _Alloc, typename _UHead, typename... _UTails> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, _Tuple_impl<_Idx, _UHead, _UTails...>&& __in) : _Inherited(__tag, __a, std::move (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))), _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), std::forward<_UHead> (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { } template<typename... _UElements> _GLIBCXX20_CONSTEXPR void _M_assign(const _Tuple_impl<_Idx, _UElements...>& __in) { _M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in); _M_tail(*this)._M_assign( _Tuple_impl<_Idx, _UElements...>::_M_tail(__in)); } template<typename _UHead, typename... _UTails> _GLIBCXX20_CONSTEXPR void _M_assign(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in) { _M_head(*this) = std::forward<_UHead> (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in)); _M_tail(*this)._M_assign( std::move(_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))); } protected: _GLIBCXX20_CONSTEXPR void _M_swap(_Tuple_impl& __in) { using std::swap; swap(_M_head(*this), _M_head(__in)); _Inherited::_M_swap(_M_tail(__in)); } }; // Basis case of inheritance recursion. template<std::size_t _Idx, typename _Head> struct _Tuple_impl<_Idx, _Head> : private _Head_base<_Idx, _Head> { template<std::size_t, typename...> friend class _Tuple_impl; typedef _Head_base<_Idx, _Head> _Base; static constexpr _Head& _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } static constexpr const _Head& _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } constexpr _Tuple_impl() : _Base() { } explicit constexpr _Tuple_impl(const _Head& __head) : _Base(__head) { } template<typename _UHead> explicit constexpr _Tuple_impl(_UHead&& __head) : _Base(std::forward<_UHead>(__head)) { } constexpr _Tuple_impl(const _Tuple_impl&) = default; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 2729. Missing SFINAE on std::pair::operator= _Tuple_impl& operator=(const _Tuple_impl&) = delete; constexpr _Tuple_impl(_Tuple_impl&& __in) noexcept(is_nothrow_move_constructible<_Head>::value) : _Base(std::forward<_Head>(_M_head(__in))) { } template<typename _UHead> constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UHead>& __in) : _Base(_Tuple_impl<_Idx, _UHead>::_M_head(__in)) { } template<typename _UHead> constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead>&& __in) : _Base(std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in))) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a) : _Base(__tag, __use_alloc<_Head>(__a)) { } template<typename _Alloc> _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, const _Head& __head) : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { } template<typename _Alloc, typename _UHead> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, _UHead&& __head) : _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), std::forward<_UHead>(__head)) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, const _Tuple_impl& __in) : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, _Tuple_impl&& __in) : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), std::forward<_Head>(_M_head(__in))) { } template<typename _Alloc, typename _UHead> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, const _Tuple_impl<_Idx, _UHead>& __in) : _Base(__use_alloc<_Head, _Alloc, const _UHead&>(__a), _Tuple_impl<_Idx, _UHead>::_M_head(__in)) { } template<typename _Alloc, typename _UHead> _GLIBCXX20_CONSTEXPR _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, _Tuple_impl<_Idx, _UHead>&& __in) : _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in))) { } template<typename _UHead> _GLIBCXX20_CONSTEXPR void _M_assign(const _Tuple_impl<_Idx, _UHead>& __in) { _M_head(*this) = _Tuple_impl<_Idx, _UHead>::_M_head(__in); } template<typename _UHead> _GLIBCXX20_CONSTEXPR void _M_assign(_Tuple_impl<_Idx, _UHead>&& __in) { _M_head(*this) = std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in)); } protected: _GLIBCXX20_CONSTEXPR void _M_swap(_Tuple_impl& __in) { using std::swap; swap(_M_head(*this), _M_head(__in)); } }; // Concept utility functions, reused in conditionally-explicit // constructors. template<bool, typename... _Types> struct _TupleConstraints { // Constraint for a non-explicit constructor. // True iff each Ti in _Types... can be constructed from Ui in _UTypes... // and every Ui is implicitly convertible to Ti. template<typename... _UTypes> static constexpr bool __is_implicitly_constructible() { return __and_<is_constructible<_Types, _UTypes>..., is_convertible<_UTypes, _Types>... >::value; } // Constraint for a non-explicit constructor. // True iff each Ti in _Types... can be constructed from Ui in _UTypes... // but not every Ui is implicitly convertible to Ti. template<typename... _UTypes> static constexpr bool __is_explicitly_constructible() { return __and_<is_constructible<_Types, _UTypes>..., __not_<__and_<is_convertible<_UTypes, _Types>...>> >::value; } static constexpr bool __is_implicitly_default_constructible() { return __and_<std::__is_implicitly_default_constructible<_Types>... >::value; } static constexpr bool __is_explicitly_default_constructible() { return __and_<is_default_constructible<_Types>..., __not_<__and_< std::__is_implicitly_default_constructible<_Types>...> >>::value; } }; // Partial specialization used when a required precondition isn't met, // e.g. when sizeof...(_Types) != sizeof...(_UTypes). template<typename... _Types> struct _TupleConstraints<false, _Types...> { template<typename... _UTypes> static constexpr bool __is_implicitly_constructible() { return false; } template<typename... _UTypes> static constexpr bool __is_explicitly_constructible() { return false; } }; /// Primary class template, tuple template<typename... _Elements> class tuple : public _Tuple_impl<0, _Elements...> { typedef _Tuple_impl<0, _Elements...> _Inherited; template<bool _Cond> using _TCC = _TupleConstraints<_Cond, _Elements...>; // Constraint for non-explicit default constructor template<bool _Dummy> using _ImplicitDefaultCtor = __enable_if_t< _TCC<_Dummy>::__is_implicitly_default_constructible(), bool>; // Constraint for explicit default constructor template<bool _Dummy> using _ExplicitDefaultCtor = __enable_if_t< _TCC<_Dummy>::__is_explicitly_default_constructible(), bool>; // Constraint for non-explicit constructors template<bool _Cond, typename... _Args> using _ImplicitCtor = __enable_if_t< _TCC<_Cond>::template __is_implicitly_constructible<_Args...>(), bool>; // Constraint for non-explicit constructors template<bool _Cond, typename... _Args> using _ExplicitCtor = __enable_if_t< _TCC<_Cond>::template __is_explicitly_constructible<_Args...>(), bool>; template<typename... _UElements> static constexpr __enable_if_t<sizeof...(_UElements) == sizeof...(_Elements), bool> __assignable() { return __and_<is_assignable<_Elements&, _UElements>...>::value; } // Condition for noexcept-specifier of an assignment operator. template<typename... _UElements> static constexpr bool __nothrow_assignable() { return __and_<is_nothrow_assignable<_Elements&, _UElements>...>::value; } // Condition for noexcept-specifier of a constructor. template<typename... _UElements> static constexpr bool __nothrow_constructible() { return __and_<is_nothrow_constructible<_Elements, _UElements>...>::value; } // Constraint for tuple(_UTypes&&...) where sizeof...(_UTypes) == 1. template<typename _Up> static constexpr bool __valid_args() { return sizeof...(_Elements) == 1 && !is_same<tuple, __remove_cvref_t<_Up>>::value; } // Constraint for tuple(_UTypes&&...) where sizeof...(_UTypes) > 1. template<typename, typename, typename... _Tail> static constexpr bool __valid_args() { return (sizeof...(_Tail) + 2) == sizeof...(_Elements); } /* Constraint for constructors with a tuple<UTypes...> parameter ensures * that the constructor is only viable when it would not interfere with * tuple(UTypes&&...) or tuple(const tuple&) or tuple(tuple&&). * Such constructors are only viable if: * either sizeof...(Types) != 1, * or (when Types... expands to T and UTypes... expands to U) * is_convertible_v<TUPLE, T>, is_constructible_v<T, TUPLE>, * and is_same_v<T, U> are all false. */ template<typename _Tuple, typename = tuple, typename = __remove_cvref_t<_Tuple>> struct _UseOtherCtor : false_type { }; // If TUPLE is convertible to the single element in *this, // then TUPLE should match tuple(UTypes&&...) instead. template<typename _Tuple, typename _Tp, typename _Up> struct _UseOtherCtor<_Tuple, tuple<_Tp>, tuple<_Up>> : __or_<is_convertible<_Tuple, _Tp>, is_constructible<_Tp, _Tuple>> { }; // If TUPLE and *this each have a single element of the same type, // then TUPLE should match a copy/move constructor instead. template<typename _Tuple, typename _Tp> struct _UseOtherCtor<_Tuple, tuple<_Tp>, tuple<_Tp>> : true_type { }; // Return true iff sizeof...(Types) == 1 && tuple_size_v<TUPLE> == 1 // and the single element in Types can be initialized from TUPLE, // or is the same type as tuple_element_t<0, TUPLE>. template<typename _Tuple> static constexpr bool __use_other_ctor() { return _UseOtherCtor<_Tuple>::value; } public: template<typename _Dummy = void, _ImplicitDefaultCtor<is_void<_Dummy>::value> = true> constexpr tuple() noexcept(__and_<is_nothrow_default_constructible<_Elements>...>::value) : _Inherited() { } template<typename _Dummy = void, _ExplicitDefaultCtor<is_void<_Dummy>::value> = false> explicit constexpr tuple() noexcept(__and_<is_nothrow_default_constructible<_Elements>...>::value) : _Inherited() { } template<bool _NotEmpty = (sizeof...(_Elements) >= 1), _ImplicitCtor<_NotEmpty, const _Elements&...> = true> constexpr tuple(const _Elements&... __elements) noexcept(__nothrow_constructible<const _Elements&...>()) : _Inherited(__elements...) { } template<bool _NotEmpty = (sizeof...(_Elements) >= 1), _ExplicitCtor<_NotEmpty, const _Elements&...> = false> explicit constexpr tuple(const _Elements&... __elements) noexcept(__nothrow_constructible<const _Elements&...>()) : _Inherited(__elements...) { } template<typename... _UElements, bool _Valid = __valid_args<_UElements...>(), _ImplicitCtor<_Valid, _UElements...> = true> constexpr tuple(_UElements&&... __elements) noexcept(__nothrow_constructible<_UElements...>()) : _Inherited(std::forward<_UElements>(__elements)...) { } template<typename... _UElements, bool _Valid = __valid_args<_UElements...>(), _ExplicitCtor<_Valid, _UElements...> = false> explicit constexpr tuple(_UElements&&... __elements) noexcept(__nothrow_constructible<_UElements...>()) : _Inherited(std::forward<_UElements>(__elements)...) { } constexpr tuple(const tuple&) = default; constexpr tuple(tuple&&) = default; template<typename... _UElements, bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements)) && !__use_other_ctor<const tuple<_UElements...>&>(), _ImplicitCtor<_Valid, const _UElements&...> = true> constexpr tuple(const tuple<_UElements...>& __in) noexcept(__nothrow_constructible<const _UElements&...>()) : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) { } template<typename... _UElements, bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements)) && !__use_other_ctor<const tuple<_UElements...>&>(), _ExplicitCtor<_Valid, const _UElements&...> = false> explicit constexpr tuple(const tuple<_UElements...>& __in) noexcept(__nothrow_constructible<const _UElements&...>()) : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) { } template<typename... _UElements, bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements)) && !__use_other_ctor<tuple<_UElements...>&&>(), _ImplicitCtor<_Valid, _UElements...> = true> constexpr tuple(tuple<_UElements...>&& __in) noexcept(__nothrow_constructible<_UElements...>()) : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { } template<typename... _UElements, bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements)) && !__use_other_ctor<tuple<_UElements...>&&>(), _ExplicitCtor<_Valid, _UElements...> = false> explicit constexpr tuple(tuple<_UElements...>&& __in) noexcept(__nothrow_constructible<_UElements...>()) : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { } // Allocator-extended constructors. template<typename _Alloc, _ImplicitDefaultCtor<is_object<_Alloc>::value> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a) : _Inherited(__tag, __a) { } template<typename _Alloc, bool _NotEmpty = (sizeof...(_Elements) >= 1), _ImplicitCtor<_NotEmpty, const _Elements&...> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const _Elements&... __elements) : _Inherited(__tag, __a, __elements...) { } template<typename _Alloc, bool _NotEmpty = (sizeof...(_Elements) >= 1), _ExplicitCtor<_NotEmpty, const _Elements&...> = false> _GLIBCXX20_CONSTEXPR explicit tuple(allocator_arg_t __tag, const _Alloc& __a, const _Elements&... __elements) : _Inherited(__tag, __a, __elements...) { } template<typename _Alloc, typename... _UElements, bool _Valid = __valid_args<_UElements...>(), _ImplicitCtor<_Valid, _UElements...> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, _UElements&&... __elements) : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...) { } template<typename _Alloc, typename... _UElements, bool _Valid = __valid_args<_UElements...>(), _ExplicitCtor<_Valid, _UElements...> = false> _GLIBCXX20_CONSTEXPR explicit tuple(allocator_arg_t __tag, const _Alloc& __a, _UElements&&... __elements) : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in) : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { } template<typename _Alloc, typename... _UElements, bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements)) && !__use_other_ctor<const tuple<_UElements...>&>(), _ImplicitCtor<_Valid, const _UElements&...> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple<_UElements...>& __in) : _Inherited(__tag, __a, static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) { } template<typename _Alloc, typename... _UElements, bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements)) && !__use_other_ctor<const tuple<_UElements...>&>(), _ExplicitCtor<_Valid, const _UElements&...> = false> _GLIBCXX20_CONSTEXPR explicit tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple<_UElements...>& __in) : _Inherited(__tag, __a, static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) { } template<typename _Alloc, typename... _UElements, bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements)) && !__use_other_ctor<tuple<_UElements...>&&>(), _ImplicitCtor<_Valid, _UElements...> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_UElements...>&& __in) : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { } template<typename _Alloc, typename... _UElements, bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements)) && !__use_other_ctor<tuple<_UElements...>&&>(), _ExplicitCtor<_Valid, _UElements...> = false> _GLIBCXX20_CONSTEXPR explicit tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_UElements...>&& __in) : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { } // tuple assignment _GLIBCXX20_CONSTEXPR tuple& operator=(typename conditional<__assignable<const _Elements&...>(), const tuple&, const __nonesuch&>::type __in) noexcept(__nothrow_assignable<const _Elements&...>()) { this->_M_assign(__in); return *this; } _GLIBCXX20_CONSTEXPR tuple& operator=(typename conditional<__assignable<_Elements...>(), tuple&&, __nonesuch&&>::type __in) noexcept(__nothrow_assignable<_Elements...>()) { this->_M_assign(std::move(__in)); return *this; } template<typename... _UElements> _GLIBCXX20_CONSTEXPR __enable_if_t<__assignable<const _UElements&...>(), tuple&> operator=(const tuple<_UElements...>& __in) noexcept(__nothrow_assignable<const _UElements&...>()) { this->_M_assign(__in); return *this; } template<typename... _UElements> _GLIBCXX20_CONSTEXPR __enable_if_t<__assignable<_UElements...>(), tuple&> operator=(tuple<_UElements...>&& __in) noexcept(__nothrow_assignable<_UElements...>()) { this->_M_assign(std::move(__in)); return *this; } // tuple swap _GLIBCXX20_CONSTEXPR void swap(tuple& __in) noexcept(__and_<__is_nothrow_swappable<_Elements>...>::value) { _Inherited::_M_swap(__in); } }; #if __cpp_deduction_guides >= 201606 template<typename... _UTypes> tuple(_UTypes...) -> tuple<_UTypes...>; template<typename _T1, typename _T2> tuple(pair<_T1, _T2>) -> tuple<_T1, _T2>; template<typename _Alloc, typename... _UTypes> tuple(allocator_arg_t, _Alloc, _UTypes...) -> tuple<_UTypes...>; template<typename _Alloc, typename _T1, typename _T2> tuple(allocator_arg_t, _Alloc, pair<_T1, _T2>) -> tuple<_T1, _T2>; template<typename _Alloc, typename... _UTypes> tuple(allocator_arg_t, _Alloc, tuple<_UTypes...>) -> tuple<_UTypes...>; #endif // Explicit specialization, zero-element tuple. template<> class tuple<> { public: void swap(tuple&) noexcept { /* no-op */ } // We need the default since we're going to define no-op // allocator constructors. tuple() = default; // No-op allocator constructors. template<typename _Alloc> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t, const _Alloc&) noexcept { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t, const _Alloc&, const tuple&) noexcept { } }; /// Partial specialization, 2-element tuple. /// Includes construction and assignment from a pair. template<typename _T1, typename _T2> class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2> { typedef _Tuple_impl<0, _T1, _T2> _Inherited; // Constraint for non-explicit default constructor template<bool _Dummy, typename _U1, typename _U2> using _ImplicitDefaultCtor = __enable_if_t< _TupleConstraints<_Dummy, _U1, _U2>:: __is_implicitly_default_constructible(), bool>; // Constraint for explicit default constructor template<bool _Dummy, typename _U1, typename _U2> using _ExplicitDefaultCtor = __enable_if_t< _TupleConstraints<_Dummy, _U1, _U2>:: __is_explicitly_default_constructible(), bool>; template<bool _Dummy> using _TCC = _TupleConstraints<_Dummy, _T1, _T2>; // Constraint for non-explicit constructors template<bool _Cond, typename _U1, typename _U2> using _ImplicitCtor = __enable_if_t< _TCC<_Cond>::template __is_implicitly_constructible<_U1, _U2>(), bool>; // Constraint for non-explicit constructors template<bool _Cond, typename _U1, typename _U2> using _ExplicitCtor = __enable_if_t< _TCC<_Cond>::template __is_explicitly_constructible<_U1, _U2>(), bool>; template<typename _U1, typename _U2> static constexpr bool __assignable() { return __and_<is_assignable<_T1&, _U1>, is_assignable<_T2&, _U2>>::value; } template<typename _U1, typename _U2> static constexpr bool __nothrow_assignable() { return __and_<is_nothrow_assignable<_T1&, _U1>, is_nothrow_assignable<_T2&, _U2>>::value; } template<typename _U1, typename _U2> static constexpr bool __nothrow_constructible() { return __and_<is_nothrow_constructible<_T1, _U1>, is_nothrow_constructible<_T2, _U2>>::value; } static constexpr bool __nothrow_default_constructible() { return __and_<is_nothrow_default_constructible<_T1>, is_nothrow_default_constructible<_T2>>::value; } template<typename _U1> static constexpr bool __is_alloc_arg() { return is_same<__remove_cvref_t<_U1>, allocator_arg_t>::value; } public: template<bool _Dummy = true, _ImplicitDefaultCtor<_Dummy, _T1, _T2> = true> constexpr tuple() noexcept(__nothrow_default_constructible()) : _Inherited() { } template<bool _Dummy = true, _ExplicitDefaultCtor<_Dummy, _T1, _T2> = false> explicit constexpr tuple() noexcept(__nothrow_default_constructible()) : _Inherited() { } template<bool _Dummy = true, _ImplicitCtor<_Dummy, const _T1&, const _T2&> = true> constexpr tuple(const _T1& __a1, const _T2& __a2) noexcept(__nothrow_constructible<const _T1&, const _T2&>()) : _Inherited(__a1, __a2) { } template<bool _Dummy = true, _ExplicitCtor<_Dummy, const _T1&, const _T2&> = false> explicit constexpr tuple(const _T1& __a1, const _T2& __a2) noexcept(__nothrow_constructible<const _T1&, const _T2&>()) : _Inherited(__a1, __a2) { } template<typename _U1, typename _U2, _ImplicitCtor<!__is_alloc_arg<_U1>(), _U1, _U2> = true> constexpr tuple(_U1&& __a1, _U2&& __a2) noexcept(__nothrow_constructible<_U1, _U2>()) : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { } template<typename _U1, typename _U2, _ExplicitCtor<!__is_alloc_arg<_U1>(), _U1, _U2> = false> explicit constexpr tuple(_U1&& __a1, _U2&& __a2) noexcept(__nothrow_constructible<_U1, _U2>()) : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { } constexpr tuple(const tuple&) = default; constexpr tuple(tuple&&) = default; template<typename _U1, typename _U2, _ImplicitCtor<true, const _U1&, const _U2&> = true> constexpr tuple(const tuple<_U1, _U2>& __in) noexcept(__nothrow_constructible<const _U1&, const _U2&>()) : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { } template<typename _U1, typename _U2, _ExplicitCtor<true, const _U1&, const _U2&> = false> explicit constexpr tuple(const tuple<_U1, _U2>& __in) noexcept(__nothrow_constructible<const _U1&, const _U2&>()) : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { } template<typename _U1, typename _U2, _ImplicitCtor<true, _U1, _U2> = true> constexpr tuple(tuple<_U1, _U2>&& __in) noexcept(__nothrow_constructible<_U1, _U2>()) : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { } template<typename _U1, typename _U2, _ExplicitCtor<true, _U1, _U2> = false> explicit constexpr tuple(tuple<_U1, _U2>&& __in) noexcept(__nothrow_constructible<_U1, _U2>()) : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { } template<typename _U1, typename _U2, _ImplicitCtor<true, const _U1&, const _U2&> = true> constexpr tuple(const pair<_U1, _U2>& __in) noexcept(__nothrow_constructible<const _U1&, const _U2&>()) : _Inherited(__in.first, __in.second) { } template<typename _U1, typename _U2, _ExplicitCtor<true, const _U1&, const _U2&> = false> explicit constexpr tuple(const pair<_U1, _U2>& __in) noexcept(__nothrow_constructible<const _U1&, const _U2&>()) : _Inherited(__in.first, __in.second) { } template<typename _U1, typename _U2, _ImplicitCtor<true, _U1, _U2> = true> constexpr tuple(pair<_U1, _U2>&& __in) noexcept(__nothrow_constructible<_U1, _U2>()) : _Inherited(std::forward<_U1>(__in.first), std::forward<_U2>(__in.second)) { } template<typename _U1, typename _U2, _ExplicitCtor<true, _U1, _U2> = false> explicit constexpr tuple(pair<_U1, _U2>&& __in) noexcept(__nothrow_constructible<_U1, _U2>()) : _Inherited(std::forward<_U1>(__in.first), std::forward<_U2>(__in.second)) { } // Allocator-extended constructors. template<typename _Alloc, _ImplicitDefaultCtor<is_object<_Alloc>::value, _T1, _T2> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a) : _Inherited(__tag, __a) { } template<typename _Alloc, bool _Dummy = true, _ImplicitCtor<_Dummy, const _T1&, const _T2&> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const _T1& __a1, const _T2& __a2) : _Inherited(__tag, __a, __a1, __a2) { } template<typename _Alloc, bool _Dummy = true, _ExplicitCtor<_Dummy, const _T1&, const _T2&> = false> explicit _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const _T1& __a1, const _T2& __a2) : _Inherited(__tag, __a, __a1, __a2) { } template<typename _Alloc, typename _U1, typename _U2, _ImplicitCtor<true, _U1, _U2> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, _U1&& __a1, _U2&& __a2) : _Inherited(__tag, __a, std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { } template<typename _Alloc, typename _U1, typename _U2, _ExplicitCtor<true, _U1, _U2> = false> explicit _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, _U1&& __a1, _U2&& __a2) : _Inherited(__tag, __a, std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { } template<typename _Alloc> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in) : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { } template<typename _Alloc, typename _U1, typename _U2, _ImplicitCtor<true, const _U1&, const _U2&> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple<_U1, _U2>& __in) : _Inherited(__tag, __a, static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { } template<typename _Alloc, typename _U1, typename _U2, _ExplicitCtor<true, const _U1&, const _U2&> = false> explicit _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple<_U1, _U2>& __in) : _Inherited(__tag, __a, static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { } template<typename _Alloc, typename _U1, typename _U2, _ImplicitCtor<true, _U1, _U2> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_U1, _U2>&& __in) : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { } template<typename _Alloc, typename _U1, typename _U2, _ExplicitCtor<true, _U1, _U2> = false> explicit _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_U1, _U2>&& __in) : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { } template<typename _Alloc, typename _U1, typename _U2, _ImplicitCtor<true, const _U1&, const _U2&> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const pair<_U1, _U2>& __in) : _Inherited(__tag, __a, __in.first, __in.second) { } template<typename _Alloc, typename _U1, typename _U2, _ExplicitCtor<true, const _U1&, const _U2&> = false> explicit _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, const pair<_U1, _U2>& __in) : _Inherited(__tag, __a, __in.first, __in.second) { } template<typename _Alloc, typename _U1, typename _U2, _ImplicitCtor<true, _U1, _U2> = true> _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, pair<_U1, _U2>&& __in) : _Inherited(__tag, __a, std::forward<_U1>(__in.first), std::forward<_U2>(__in.second)) { } template<typename _Alloc, typename _U1, typename _U2, _ExplicitCtor<true, _U1, _U2> = false> explicit _GLIBCXX20_CONSTEXPR tuple(allocator_arg_t __tag, const _Alloc& __a, pair<_U1, _U2>&& __in) : _Inherited(__tag, __a, std::forward<_U1>(__in.first), std::forward<_U2>(__in.second)) { } // Tuple assignment. _GLIBCXX20_CONSTEXPR tuple& operator=(typename conditional<__assignable<const _T1&, const _T2&>(), const tuple&, const __nonesuch&>::type __in) noexcept(__nothrow_assignable<const _T1&, const _T2&>()) { this->_M_assign(__in); return *this; } _GLIBCXX20_CONSTEXPR tuple& operator=(typename conditional<__assignable<_T1, _T2>(), tuple&&, __nonesuch&&>::type __in) noexcept(__nothrow_assignable<_T1, _T2>()) { this->_M_assign(std::move(__in)); return *this; } template<typename _U1, typename _U2> _GLIBCXX20_CONSTEXPR __enable_if_t<__assignable<const _U1&, const _U2&>(), tuple&> operator=(const tuple<_U1, _U2>& __in) noexcept(__nothrow_assignable<const _U1&, const _U2&>()) { this->_M_assign(__in); return *this; } template<typename _U1, typename _U2> _GLIBCXX20_CONSTEXPR __enable_if_t<__assignable<_U1, _U2>(), tuple&> operator=(tuple<_U1, _U2>&& __in) noexcept(__nothrow_assignable<_U1, _U2>()) { this->_M_assign(std::move(__in)); return *this; } template<typename _U1, typename _U2> _GLIBCXX20_CONSTEXPR __enable_if_t<__assignable<const _U1&, const _U2&>(), tuple&> operator=(const pair<_U1, _U2>& __in) noexcept(__nothrow_assignable<const _U1&, const _U2&>()) { this->_M_head(*this) = __in.first; this->_M_tail(*this)._M_head(*this) = __in.second; return *this; } template<typename _U1, typename _U2> _GLIBCXX20_CONSTEXPR __enable_if_t<__assignable<_U1, _U2>(), tuple&> operator=(pair<_U1, _U2>&& __in) noexcept(__nothrow_assignable<_U1, _U2>()) { this->_M_head(*this) = std::forward<_U1>(__in.first); this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second); return *this; } _GLIBCXX20_CONSTEXPR void swap(tuple& __in) noexcept(__and_<__is_nothrow_swappable<_T1>, __is_nothrow_swappable<_T2>>::value) { _Inherited::_M_swap(__in); } }; /// class tuple_size template<typename... _Elements> struct tuple_size<tuple<_Elements...>> : public integral_constant<std::size_t, sizeof...(_Elements)> { }; #if __cplusplus > 201402L template <typename _Tp> inline constexpr size_t tuple_size_v = tuple_size<_Tp>::value; #endif /** * Recursive case for tuple_element: strip off the first element in * the tuple and retrieve the (i-1)th element of the remaining tuple. */ template<std::size_t __i, typename _Head, typename... _Tail> struct tuple_element<__i, tuple<_Head, _Tail...> > : tuple_element<__i - 1, tuple<_Tail...> > { }; /** * Basis case for tuple_element: The first element is the one we're seeking. */ template<typename _Head, typename... _Tail> struct tuple_element<0, tuple<_Head, _Tail...> > { typedef _Head type; }; /** * Error case for tuple_element: invalid index. */ template<size_t __i> struct tuple_element<__i, tuple<>> { static_assert(__i < tuple_size<tuple<>>::value, "tuple index is in range"); }; template<std::size_t __i, typename _Head, typename... _Tail> constexpr _Head& __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } template<std::size_t __i, typename _Head, typename... _Tail> constexpr const _Head& __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } /// Return a reference to the ith element of a tuple. template<std::size_t __i, typename... _Elements> constexpr __tuple_element_t<__i, tuple<_Elements...>>& get(tuple<_Elements...>& __t) noexcept { return std::__get_helper<__i>(__t); } /// Return a const reference to the ith element of a const tuple. template<std::size_t __i, typename... _Elements> constexpr const __tuple_element_t<__i, tuple<_Elements...>>& get(const tuple<_Elements...>& __t) noexcept { return std::__get_helper<__i>(__t); } /// Return an rvalue reference to the ith element of a tuple rvalue. template<std::size_t __i, typename... _Elements> constexpr __tuple_element_t<__i, tuple<_Elements...>>&& get(tuple<_Elements...>&& __t) noexcept { typedef __tuple_element_t<__i, tuple<_Elements...>> __element_type; return std::forward<__element_type&&>(std::get<__i>(__t)); } /// Return a const rvalue reference to the ith element of a const tuple rvalue. template<std::size_t __i, typename... _Elements> constexpr const __tuple_element_t<__i, tuple<_Elements...>>&& get(const tuple<_Elements...>&& __t) noexcept { typedef __tuple_element_t<__i, tuple<_Elements...>> __element_type; return std::forward<const __element_type&&>(std::get<__i>(__t)); } #if __cplusplus >= 201402L #define __cpp_lib_tuples_by_type 201304 template<typename _Head, size_t __i, typename... _Tail> constexpr _Head& __get_helper2(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } template<typename _Head, size_t __i, typename... _Tail> constexpr const _Head& __get_helper2(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } /// Return a reference to the unique element of type _Tp of a tuple. template <typename _Tp, typename... _Types> constexpr _Tp& get(tuple<_Types...>& __t) noexcept { return std::__get_helper2<_Tp>(__t); } /// Return a reference to the unique element of type _Tp of a tuple rvalue. template <typename _Tp, typename... _Types> constexpr _Tp&& get(tuple<_Types...>&& __t) noexcept { return std::forward<_Tp&&>(std::__get_helper2<_Tp>(__t)); } /// Return a const reference to the unique element of type _Tp of a tuple. template <typename _Tp, typename... _Types> constexpr const _Tp& get(const tuple<_Types...>& __t) noexcept { return std::__get_helper2<_Tp>(__t); } /// Return a const reference to the unique element of type _Tp of /// a const tuple rvalue. template <typename _Tp, typename... _Types> constexpr const _Tp&& get(const tuple<_Types...>&& __t) noexcept { return std::forward<const _Tp&&>(std::__get_helper2<_Tp>(__t)); } #endif // This class performs the comparison operations on tuples template<typename _Tp, typename _Up, size_t __i, size_t __size> struct __tuple_compare { static constexpr bool __eq(const _Tp& __t, const _Up& __u) { return bool(std::get<__i>(__t) == std::get<__i>(__u)) && __tuple_compare<_Tp, _Up, __i + 1, __size>::__eq(__t, __u); } static constexpr bool __less(const _Tp& __t, const _Up& __u) { return bool(std::get<__i>(__t) < std::get<__i>(__u)) || (!bool(std::get<__i>(__u) < std::get<__i>(__t)) && __tuple_compare<_Tp, _Up, __i + 1, __size>::__less(__t, __u)); } }; template<typename _Tp, typename _Up, size_t __size> struct __tuple_compare<_Tp, _Up, __size, __size> { static constexpr bool __eq(const _Tp&, const _Up&) { return true; } static constexpr bool __less(const _Tp&, const _Up&) { return false; } }; template<typename... _TElements, typename... _UElements> constexpr bool operator==(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { static_assert(sizeof...(_TElements) == sizeof...(_UElements), "tuple objects can only be compared if they have equal sizes."); using __compare = __tuple_compare<tuple<_TElements...>, tuple<_UElements...>, 0, sizeof...(_TElements)>; return __compare::__eq(__t, __u); } #if __cpp_lib_three_way_comparison template<typename _Cat, typename _Tp, typename _Up> constexpr _Cat __tuple_cmp(const _Tp&, const _Up&, index_sequence<>) { return _Cat::equivalent; } template<typename _Cat, typename _Tp, typename _Up, size_t _Idx0, size_t... _Idxs> constexpr _Cat __tuple_cmp(const _Tp& __t, const _Up& __u, index_sequence<_Idx0, _Idxs...>) { auto __c = __detail::__synth3way(std::get<_Idx0>(__t), std::get<_Idx0>(__u)); if (__c != 0) return __c; return std::__tuple_cmp<_Cat>(__t, __u, index_sequence<_Idxs...>()); } template<typename... _Tps, typename... _Ups> constexpr common_comparison_category_t<__detail::__synth3way_t<_Tps, _Ups>...> operator<=>(const tuple<_Tps...>& __t, const tuple<_Ups...>& __u) { using _Cat = common_comparison_category_t<__detail::__synth3way_t<_Tps, _Ups>...>; return std::__tuple_cmp<_Cat>(__t, __u, index_sequence_for<_Tps...>()); } #else template<typename... _TElements, typename... _UElements> constexpr bool operator<(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { static_assert(sizeof...(_TElements) == sizeof...(_UElements), "tuple objects can only be compared if they have equal sizes."); using __compare = __tuple_compare<tuple<_TElements...>, tuple<_UElements...>, 0, sizeof...(_TElements)>; return __compare::__less(__t, __u); } template<typename... _TElements, typename... _UElements> constexpr bool operator!=(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { return !(__t == __u); } template<typename... _TElements, typename... _UElements> constexpr bool operator>(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { return __u < __t; } template<typename... _TElements, typename... _UElements> constexpr bool operator<=(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { return !(__u < __t); } template<typename... _TElements, typename... _UElements> constexpr bool operator>=(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { return !(__t < __u); } #endif // three_way_comparison // NB: DR 705. template<typename... _Elements> constexpr tuple<typename __decay_and_strip<_Elements>::__type...> make_tuple(_Elements&&... __args) { typedef tuple<typename __decay_and_strip<_Elements>::__type...> __result_type; return __result_type(std::forward<_Elements>(__args)...); } // _GLIBCXX_RESOLVE_LIB_DEFECTS // 2275. Why is forward_as_tuple not constexpr? /// std::forward_as_tuple template<typename... _Elements> constexpr tuple<_Elements&&...> forward_as_tuple(_Elements&&... __args) noexcept { return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); } template<size_t, typename, typename, size_t> struct __make_tuple_impl; template<size_t _Idx, typename _Tuple, typename... _Tp, size_t _Nm> struct __make_tuple_impl<_Idx, tuple<_Tp...>, _Tuple, _Nm> : __make_tuple_impl<_Idx + 1, tuple<_Tp..., __tuple_element_t<_Idx, _Tuple>>, _Tuple, _Nm> { }; template<std::size_t _Nm, typename _Tuple, typename... _Tp> struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm> { typedef tuple<_Tp...> __type; }; template<typename _Tuple> struct __do_make_tuple : __make_tuple_impl<0, tuple<>, _Tuple, std::tuple_size<_Tuple>::value> { }; // Returns the std::tuple equivalent of a tuple-like type. template<typename _Tuple> struct __make_tuple : public __do_make_tuple<__remove_cvref_t<_Tuple>> { }; // Combines several std::tuple's into a single one. template<typename...> struct __combine_tuples; template<> struct __combine_tuples<> { typedef tuple<> __type; }; template<typename... _Ts> struct __combine_tuples<tuple<_Ts...>> { typedef tuple<_Ts...> __type; }; template<typename... _T1s, typename... _T2s, typename... _Rem> struct __combine_tuples<tuple<_T1s...>, tuple<_T2s...>, _Rem...> { typedef typename __combine_tuples<tuple<_T1s..., _T2s...>, _Rem...>::__type __type; }; // Computes the result type of tuple_cat given a set of tuple-like types. template<typename... _Tpls> struct __tuple_cat_result { typedef typename __combine_tuples <typename __make_tuple<_Tpls>::__type...>::__type __type; }; // Helper to determine the index set for the first tuple-like // type of a given set. template<typename...> struct __make_1st_indices; template<> struct __make_1st_indices<> { typedef std::_Index_tuple<> __type; }; template<typename _Tp, typename... _Tpls> struct __make_1st_indices<_Tp, _Tpls...> { typedef typename std::_Build_index_tuple<std::tuple_size< typename std::remove_reference<_Tp>::type>::value>::__type __type; }; // Performs the actual concatenation by step-wise expanding tuple-like // objects into the elements, which are finally forwarded into the // result tuple. template<typename _Ret, typename _Indices, typename... _Tpls> struct __tuple_concater; template<typename _Ret, std::size_t... _Is, typename _Tp, typename... _Tpls> struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...> { template<typename... _Us> static constexpr _Ret _S_do(_Tp&& __tp, _Tpls&&... __tps, _Us&&... __us) { typedef typename __make_1st_indices<_Tpls...>::__type __idx; typedef __tuple_concater<_Ret, __idx, _Tpls...> __next; return __next::_S_do(std::forward<_Tpls>(__tps)..., std::forward<_Us>(__us)..., std::get<_Is>(std::forward<_Tp>(__tp))...); } }; template<typename _Ret> struct __tuple_concater<_Ret, std::_Index_tuple<>> { template<typename... _Us> static constexpr _Ret _S_do(_Us&&... __us) { return _Ret(std::forward<_Us>(__us)...); } }; /// tuple_cat template<typename... _Tpls, typename = typename enable_if<__and_<__is_tuple_like<_Tpls>...>::value>::type> constexpr auto tuple_cat(_Tpls&&... __tpls) -> typename __tuple_cat_result<_Tpls...>::__type { typedef typename __tuple_cat_result<_Tpls...>::__type __ret; typedef typename __make_1st_indices<_Tpls...>::__type __idx; typedef __tuple_concater<__ret, __idx, _Tpls...> __concater; return __concater::_S_do(std::forward<_Tpls>(__tpls)...); } // _GLIBCXX_RESOLVE_LIB_DEFECTS // 2301. Why is tie not constexpr? /// tie template<typename... _Elements> constexpr tuple<_Elements&...> tie(_Elements&... __args) noexcept { return tuple<_Elements&...>(__args...); } /// swap template<typename... _Elements> _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<_Elements>...>::value >::type #else void #endif swap(tuple<_Elements...>& __x, tuple<_Elements...>& __y) noexcept(noexcept(__x.swap(__y))) { __x.swap(__y); } #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 template<typename... _Elements> _GLIBCXX20_CONSTEXPR typename enable_if<!__and_<__is_swappable<_Elements>...>::value>::type swap(tuple<_Elements...>&, tuple<_Elements...>&) = delete; #endif // A class (and instance) which can be used in 'tie' when an element // of a tuple is not required. // _GLIBCXX14_CONSTEXPR // 2933. PR for LWG 2773 could be clearer struct _Swallow_assign { template<class _Tp> _GLIBCXX14_CONSTEXPR const _Swallow_assign& operator=(const _Tp&) const { return *this; } }; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 2773. Making std::ignore constexpr _GLIBCXX17_INLINE constexpr _Swallow_assign ignore{}; /// Partial specialization for tuples template<typename... _Types, typename _Alloc> struct uses_allocator<tuple<_Types...>, _Alloc> : true_type { }; // See stl_pair.h... /** "piecewise construction" using a tuple of arguments for each member. * * @param __first Arguments for the first member of the pair. * @param __second Arguments for the second member of the pair. * * The elements of each tuple will be used as the constructor arguments * for the data members of the pair. */ template<class _T1, class _T2> template<typename... _Args1, typename... _Args2> _GLIBCXX20_CONSTEXPR inline pair<_T1, _T2>:: pair(piecewise_construct_t, tuple<_Args1...> __first, tuple<_Args2...> __second) : pair(__first, __second, typename _Build_index_tuple<sizeof...(_Args1)>::__type(), typename _Build_index_tuple<sizeof...(_Args2)>::__type()) { } template<class _T1, class _T2> template<typename... _Args1, std::size_t... _Indexes1, typename... _Args2, std::size_t... _Indexes2> _GLIBCXX20_CONSTEXPR inline pair<_T1, _T2>:: pair(tuple<_Args1...>& __tuple1, tuple<_Args2...>& __tuple2, _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>) : first(std::forward<_Args1>(std::get<_Indexes1>(__tuple1))...), second(std::forward<_Args2>(std::get<_Indexes2>(__tuple2))...) { } #if __cplusplus >= 201703L // Unpack a std::tuple into a type trait and use its value. // For cv std::tuple<_Up> the result is _Trait<_Tp, cv _Up...>::value. // For cv std::tuple<_Up>& the result is _Trait<_Tp, cv _Up&...>::value. // Otherwise the result is false (because we don't know if std::get throws). template<template<typename...> class _Trait, typename _Tp, typename _Tuple> inline constexpr bool __unpack_std_tuple = false; template<template<typename...> class _Trait, typename _Tp, typename... _Up> inline constexpr bool __unpack_std_tuple<_Trait, _Tp, tuple<_Up...>> = _Trait<_Tp, _Up...>::value; template<template<typename...> class _Trait, typename _Tp, typename... _Up> inline constexpr bool __unpack_std_tuple<_Trait, _Tp, tuple<_Up...>&> = _Trait<_Tp, _Up&...>::value; template<template<typename...> class _Trait, typename _Tp, typename... _Up> inline constexpr bool __unpack_std_tuple<_Trait, _Tp, const tuple<_Up...>> = _Trait<_Tp, const _Up...>::value; template<template<typename...> class _Trait, typename _Tp, typename... _Up> inline constexpr bool __unpack_std_tuple<_Trait, _Tp, const tuple<_Up...>&> = _Trait<_Tp, const _Up&...>::value; # define __cpp_lib_apply 201603 template <typename _Fn, typename _Tuple, size_t... _Idx> constexpr decltype(auto) __apply_impl(_Fn&& __f, _Tuple&& __t, index_sequence<_Idx...>) { return std::__invoke(std::forward<_Fn>(__f), std::get<_Idx>(std::forward<_Tuple>(__t))...); } template <typename _Fn, typename _Tuple> constexpr decltype(auto) apply(_Fn&& __f, _Tuple&& __t) noexcept(__unpack_std_tuple<is_nothrow_invocable, _Fn, _Tuple>) { using _Indices = make_index_sequence<tuple_size_v<remove_reference_t<_Tuple>>>; return std::__apply_impl(std::forward<_Fn>(__f), std::forward<_Tuple>(__t), _Indices{}); } #define __cpp_lib_make_from_tuple 201606 template <typename _Tp, typename _Tuple, size_t... _Idx> constexpr _Tp __make_from_tuple_impl(_Tuple&& __t, index_sequence<_Idx...>) { return _Tp(std::get<_Idx>(std::forward<_Tuple>(__t))...); } template <typename _Tp, typename _Tuple> constexpr _Tp make_from_tuple(_Tuple&& __t) noexcept(__unpack_std_tuple<is_nothrow_constructible, _Tp, _Tuple>) { return __make_from_tuple_impl<_Tp>( std::forward<_Tuple>(__t), make_index_sequence<tuple_size_v<remove_reference_t<_Tuple>>>{}); } #endif // C++17 /// @} _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // C++11 #endif // _GLIBCXX_TUPLE