|  | // -*- C++ -*- | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | 
|  | // See https://llvm.org/LICENSE.txt for license information. | 
|  | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #ifndef _LIBCPP_TUPLE | 
|  | #define _LIBCPP_TUPLE | 
|  |  | 
|  | // clang-format off | 
|  |  | 
|  | /* | 
|  | tuple synopsis | 
|  |  | 
|  | namespace std | 
|  | { | 
|  |  | 
|  | template <class... T> | 
|  | class tuple { | 
|  | public: | 
|  | explicit(see-below) constexpr tuple(); | 
|  | explicit(see-below) tuple(const T&...);  // constexpr in C++14 | 
|  | template <class... U> | 
|  | explicit(see-below) tuple(U&&...);  // constexpr in C++14 | 
|  | tuple(const tuple&) = default; | 
|  | tuple(tuple&&) = default; | 
|  |  | 
|  | template<class... UTypes> | 
|  | constexpr explicit(see-below) tuple(tuple<UTypes...>&);  // C++23 | 
|  | template <class... U> | 
|  | explicit(see-below) tuple(const tuple<U...>&);  // constexpr in C++14 | 
|  | template <class... U> | 
|  | explicit(see-below) tuple(tuple<U...>&&);  // constexpr in C++14 | 
|  | template<class... UTypes> | 
|  | constexpr explicit(see-below) tuple(const tuple<UTypes...>&&); // C++23 | 
|  |  | 
|  | template<class U1, class U2> | 
|  | constexpr explicit(see-below) tuple(pair<U1, U2>&);  // iff sizeof...(Types) == 2 // C++23 | 
|  | template <class U1, class U2> | 
|  | explicit(see-below) tuple(const pair<U1, U2>&); // iff sizeof...(T) == 2 // constexpr in C++14 | 
|  | template <class U1, class U2> | 
|  | explicit(see-below) tuple(pair<U1, U2>&&); // iff sizeof...(T) == 2  // constexpr in C++14 | 
|  | template<class U1, class U2> | 
|  | constexpr explicit(see-below) tuple(const pair<U1, U2>&&);  // iff sizeof...(Types) == 2 // C++23 | 
|  |  | 
|  | // allocator-extended constructors | 
|  | template <class Alloc> | 
|  | tuple(allocator_arg_t, const Alloc& a); | 
|  | template <class Alloc> | 
|  | explicit(see-below) tuple(allocator_arg_t, const Alloc& a, const T&...);          // constexpr in C++20 | 
|  | template <class Alloc, class... U> | 
|  | explicit(see-below) tuple(allocator_arg_t, const Alloc& a, U&&...);               // constexpr in C++20 | 
|  | template <class Alloc> | 
|  | tuple(allocator_arg_t, const Alloc& a, const tuple&);                             // constexpr in C++20 | 
|  | template <class Alloc> | 
|  | tuple(allocator_arg_t, const Alloc& a, tuple&&);                                  // constexpr in C++20 | 
|  | template<class Alloc, class... UTypes> | 
|  | constexpr explicit(see-below) | 
|  | tuple(allocator_arg_t, const Alloc& a, tuple<UTypes...>&);                      // C++23 | 
|  | template <class Alloc, class... U> | 
|  | explicit(see-below) tuple(allocator_arg_t, const Alloc& a, const tuple<U...>&);   // constexpr in C++20 | 
|  | template <class Alloc, class... U> | 
|  | explicit(see-below) tuple(allocator_arg_t, const Alloc& a, tuple<U...>&&);        // constexpr in C++20 | 
|  | template<class Alloc, class... UTypes> | 
|  | constexpr explicit(see-below) | 
|  | tuple(allocator_arg_t, const Alloc& a, const tuple<UTypes...>&&);               // C++23 | 
|  | template<class Alloc, class U1, class U2> | 
|  | constexpr explicit(see-below) | 
|  | tuple(allocator_arg_t, const Alloc& a, pair<U1, U2>&);                          // C++23 | 
|  | template <class Alloc, class U1, class U2> | 
|  | explicit(see-below) tuple(allocator_arg_t, const Alloc& a, const pair<U1, U2>&);  // constexpr in C++20 | 
|  | template <class Alloc, class U1, class U2> | 
|  | explicit(see-below) tuple(allocator_arg_t, const Alloc& a, pair<U1, U2>&&);       // constexpr in C++20 | 
|  | template<class Alloc, class U1, class U2> | 
|  | constexpr explicit(see-below) | 
|  | tuple(allocator_arg_t, const Alloc& a, const pair<U1, U2>&&);                   // C++23 | 
|  |  | 
|  | tuple& operator=(const tuple&);                                                       // constexpr in C++20 | 
|  | constexpr const tuple& operator=(const tuple&) const;                                 // C++23 | 
|  | tuple& operator=(tuple&&) noexcept(is_nothrow_move_assignable_v<T> && ...);           // constexpr in C++20 | 
|  | constexpr const tuple& operator=(tuple&&) const;                                      // C++23 | 
|  | template <class... U> | 
|  | tuple& operator=(const tuple<U...>&);                                             // constexpr in C++20 | 
|  | template<class... UTypes> | 
|  | constexpr const tuple& operator=(const tuple<UTypes...>&) const;                  // C++23 | 
|  | template <class... U> | 
|  | tuple& operator=(tuple<U...>&&);                                                  // constexpr in C++20 | 
|  | template<class... UTypes> | 
|  | constexpr const tuple& operator=(tuple<UTypes...>&&) const;                       // C++23 | 
|  | template <class U1, class U2> | 
|  | tuple& operator=(const pair<U1, U2>&); // iff sizeof...(T) == 2                   // constexpr in C++20 | 
|  | template<class U1, class U2> | 
|  | constexpr const tuple& operator=(const pair<U1, U2>&) const;   // iff sizeof...(Types) == 2 // C++23 | 
|  | template <class U1, class U2> | 
|  | tuple& operator=(pair<U1, U2>&&); // iff sizeof...(T) == 2                        // constexpr in C++20 | 
|  | template<class U1, class U2> | 
|  | constexpr const tuple& operator=(pair<U1, U2>&&) const;  // iff sizeof...(Types) == 2 // C++23 | 
|  |  | 
|  | template<class U, size_t N> | 
|  | tuple& operator=(array<U, N> const&) // iff sizeof...(T) == N, EXTENSION | 
|  | template<class U, size_t N> | 
|  | tuple& operator=(array<U, N>&&) // iff sizeof...(T) == N, EXTENSION | 
|  |  | 
|  | void swap(tuple&) noexcept(AND(swap(declval<T&>(), declval<T&>())...));               // constexpr in C++20 | 
|  | constexpr void swap(const tuple&) const noexcept(see-below);                          // C++23 | 
|  | }; | 
|  |  | 
|  |  | 
|  | template<class... TTypes, class... UTypes, template<class> class TQual, template<class> class UQual> // since C++23 | 
|  | requires requires { typename tuple<common_reference_t<TQual<TTypes>, UQual<UTypes>>...>; } | 
|  | struct basic_common_reference<tuple<TTypes...>, tuple<UTypes...>, TQual, UQual> { | 
|  | using type = tuple<common_reference_t<TQual<TTypes>, UQual<UTypes>>...>; | 
|  | }; | 
|  |  | 
|  | template<class... TTypes, class... UTypes>                                // since C++23 | 
|  | requires requires { typename tuple<common_type_t<TTypes, UTypes>...>; } | 
|  | struct common_type<tuple<TTypes...>, tuple<UTypes...>> { | 
|  | using type = tuple<common_type_t<TTypes, UTypes>...>; | 
|  | }; | 
|  |  | 
|  | template <class ...T> | 
|  | tuple(T...) -> tuple<T...>;                                         // since C++17 | 
|  | template <class T1, class T2> | 
|  | tuple(pair<T1, T2>) -> tuple<T1, T2>;                               // since C++17 | 
|  | template <class Alloc, class ...T> | 
|  | tuple(allocator_arg_t, Alloc, T...) -> tuple<T...>;                 // since C++17 | 
|  | template <class Alloc, class T1, class T2> | 
|  | tuple(allocator_arg_t, Alloc, pair<T1, T2>) -> tuple<T1, T2>;       // since C++17 | 
|  | template <class Alloc, class ...T> | 
|  | tuple(allocator_arg_t, Alloc, tuple<T...>) -> tuple<T...>;          // since C++17 | 
|  |  | 
|  | struct ignore-type { // exposition only                             // Since C++26 | 
|  | constexpr const ignore-type& | 
|  | operator=(const auto &) const noexcept | 
|  | { return *this; } | 
|  | }; | 
|  | inline constexpr ignore-type ignore; | 
|  |  | 
|  | template <class... T> tuple<V...>  make_tuple(T&&...); // constexpr in C++14 | 
|  | template <class... T> tuple<ATypes...> forward_as_tuple(T&&...) noexcept; // constexpr in C++14 | 
|  | template <class... T> tuple<T&...> tie(T&...) noexcept; // constexpr in C++14 | 
|  | template <class... Tuples> tuple<CTypes...> tuple_cat(Tuples&&... tpls); // constexpr in C++14 | 
|  |  | 
|  | // [tuple.apply], calling a function with a tuple of arguments: | 
|  | template <class F, class Tuple> | 
|  | constexpr decltype(auto) apply(F&& f, Tuple&& t) noexcept(see below);  // C++17 noexcept since C++23 | 
|  | template <class T, class Tuple> | 
|  | constexpr T make_from_tuple(Tuple&& t); // C++17 | 
|  |  | 
|  | // 20.4.1.4, tuple helper classes: | 
|  | template <class T> struct tuple_size; // undefined | 
|  | template <class... T> struct tuple_size<tuple<T...>>; | 
|  | template <class T> | 
|  | inline constexpr size_t tuple_size_v = tuple_size<T>::value; // C++17 | 
|  | template <size_t I, class T> struct tuple_element; // undefined | 
|  | template <size_t I, class... T> struct tuple_element<I, tuple<T...>>; | 
|  | template <size_t I, class T> | 
|  | using tuple_element_t = typename tuple_element <I, T>::type; // C++14 | 
|  |  | 
|  | // 20.4.1.5, element access: | 
|  | template <size_t I, class... T> | 
|  | typename tuple_element<I, tuple<T...>>::type& | 
|  | get(tuple<T...>&) noexcept; // constexpr in C++14 | 
|  | template <size_t I, class... T> | 
|  | const typename tuple_element<I, tuple<T...>>::type& | 
|  | get(const tuple<T...>&) noexcept; // constexpr in C++14 | 
|  | template <size_t I, class... T> | 
|  | typename tuple_element<I, tuple<T...>>::type&& | 
|  | get(tuple<T...>&&) noexcept; // constexpr in C++14 | 
|  | template <size_t I, class... T> | 
|  | const typename tuple_element<I, tuple<T...>>::type&& | 
|  | get(const tuple<T...>&&) noexcept; // constexpr in C++14 | 
|  |  | 
|  | template <class T1, class... T> | 
|  | constexpr T1& get(tuple<T...>&) noexcept;  // C++14 | 
|  | template <class T1, class... T> | 
|  | constexpr const T1& get(const tuple<T...>&) noexcept;   // C++14 | 
|  | template <class T1, class... T> | 
|  | constexpr T1&& get(tuple<T...>&&) noexcept;   // C++14 | 
|  | template <class T1, class... T> | 
|  | constexpr const T1&& get(const tuple<T...>&&) noexcept;   // C++14 | 
|  |  | 
|  | // 20.4.1.6, relational operators: | 
|  | template<class... T, class... U> bool operator==(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14 | 
|  | template<class... T, class... U> bool operator<(const tuple<T...>&, const tuple<U...>&);  // constexpr in C++14, removed in C++20 | 
|  | template<class... T, class... U> bool operator!=(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14, removed in C++20 | 
|  | template<class... T, class... U> bool operator>(const tuple<T...>&, const tuple<U...>&);  // constexpr in C++14, removed in C++20 | 
|  | template<class... T, class... U> bool operator<=(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14, removed in C++20 | 
|  | template<class... T, class... U> bool operator>=(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14, removed in C++20 | 
|  | template<class... T, class... U> | 
|  | constexpr common_comparison_category_t<synth-three-way-result<T, U>...> | 
|  | operator<=>(const tuple<T...>&, const tuple<U...>&);                                  // since C++20 | 
|  |  | 
|  | template <class... Types, class Alloc> | 
|  | struct uses_allocator<tuple<Types...>, Alloc>; | 
|  |  | 
|  | template <class... Types> | 
|  | void | 
|  | swap(tuple<Types...>& x, tuple<Types...>& y) noexcept(noexcept(x.swap(y))); | 
|  |  | 
|  | template <class... Types> | 
|  | constexpr void swap(const tuple<Types...>& x, const tuple<Types...>& y) noexcept(see-below);   // C++23 | 
|  |  | 
|  | }  // std | 
|  |  | 
|  | */ | 
|  |  | 
|  | // clang-format on | 
|  |  | 
|  | #if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS) | 
|  | #  include <__cxx03/__config> | 
|  | #else | 
|  | #  include <__compare/common_comparison_category.h> | 
|  | #  include <__compare/ordering.h> | 
|  | #  include <__compare/synth_three_way.h> | 
|  | #  include <__concepts/boolean_testable.h> | 
|  | #  include <__config> | 
|  | #  include <__cstddef/size_t.h> | 
|  | #  include <__fwd/array.h> | 
|  | #  include <__fwd/pair.h> | 
|  | #  include <__fwd/tuple.h> | 
|  | #  include <__memory/allocator_arg_t.h> | 
|  | #  include <__memory/uses_allocator.h> | 
|  | #  include <__tuple/find_index.h> | 
|  | #  include <__tuple/ignore.h> | 
|  | #  include <__tuple/make_tuple_types.h> | 
|  | #  include <__tuple/sfinae_helpers.h> | 
|  | #  include <__tuple/tuple_element.h> | 
|  | #  include <__tuple/tuple_indices.h> | 
|  | #  include <__tuple/tuple_like_ext.h> | 
|  | #  include <__tuple/tuple_size.h> | 
|  | #  include <__tuple/tuple_types.h> | 
|  | #  include <__type_traits/common_reference.h> | 
|  | #  include <__type_traits/common_type.h> | 
|  | #  include <__type_traits/conditional.h> | 
|  | #  include <__type_traits/conjunction.h> | 
|  | #  include <__type_traits/copy_cvref.h> | 
|  | #  include <__type_traits/disjunction.h> | 
|  | #  include <__type_traits/enable_if.h> | 
|  | #  include <__type_traits/invoke.h> | 
|  | #  include <__type_traits/is_arithmetic.h> | 
|  | #  include <__type_traits/is_assignable.h> | 
|  | #  include <__type_traits/is_constructible.h> | 
|  | #  include <__type_traits/is_convertible.h> | 
|  | #  include <__type_traits/is_empty.h> | 
|  | #  include <__type_traits/is_final.h> | 
|  | #  include <__type_traits/is_implicitly_default_constructible.h> | 
|  | #  include <__type_traits/is_nothrow_assignable.h> | 
|  | #  include <__type_traits/is_nothrow_constructible.h> | 
|  | #  include <__type_traits/is_reference.h> | 
|  | #  include <__type_traits/is_replaceable.h> | 
|  | #  include <__type_traits/is_same.h> | 
|  | #  include <__type_traits/is_swappable.h> | 
|  | #  include <__type_traits/is_trivially_relocatable.h> | 
|  | #  include <__type_traits/lazy.h> | 
|  | #  include <__type_traits/maybe_const.h> | 
|  | #  include <__type_traits/nat.h> | 
|  | #  include <__type_traits/negation.h> | 
|  | #  include <__type_traits/reference_constructs_from_temporary.h> | 
|  | #  include <__type_traits/remove_cv.h> | 
|  | #  include <__type_traits/remove_cvref.h> | 
|  | #  include <__type_traits/remove_reference.h> | 
|  | #  include <__type_traits/unwrap_ref.h> | 
|  | #  include <__utility/declval.h> | 
|  | #  include <__utility/forward.h> | 
|  | #  include <__utility/integer_sequence.h> | 
|  | #  include <__utility/move.h> | 
|  | #  include <__utility/piecewise_construct.h> | 
|  | #  include <__utility/swap.h> | 
|  | #  include <version> | 
|  |  | 
|  | // standard-mandated includes | 
|  |  | 
|  | // [tuple.syn] | 
|  | #  include <compare> | 
|  |  | 
|  | #  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) | 
|  | #    pragma GCC system_header | 
|  | #  endif | 
|  |  | 
|  | _LIBCPP_PUSH_MACROS | 
|  | #  include <__undef_macros> | 
|  |  | 
|  | _LIBCPP_BEGIN_NAMESPACE_STD | 
|  |  | 
|  | #  ifndef _LIBCPP_CXX03_LANG | 
|  |  | 
|  | // __tuple_leaf | 
|  |  | 
|  | template <size_t _Ip, class _Hp, bool = is_empty<_Hp>::value && !__libcpp_is_final<_Hp>::value > | 
|  | class __tuple_leaf; | 
|  |  | 
|  | template <size_t _Ip, class _Hp, bool _Ep> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void | 
|  | swap(__tuple_leaf<_Ip, _Hp, _Ep>& __x, __tuple_leaf<_Ip, _Hp, _Ep>& __y) noexcept(__is_nothrow_swappable_v<_Hp>) { | 
|  | swap(__x.get(), __y.get()); | 
|  | } | 
|  |  | 
|  | template <size_t _Ip, class _Hp, bool _Ep> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void | 
|  | swap(const __tuple_leaf<_Ip, _Hp, _Ep>& __x, | 
|  | const __tuple_leaf<_Ip, _Hp, _Ep>& __y) noexcept(__is_nothrow_swappable_v<const _Hp>) { | 
|  | swap(__x.get(), __y.get()); | 
|  | } | 
|  |  | 
|  | template <size_t _Ip, class _Hp, bool> | 
|  | class __tuple_leaf { | 
|  | _Hp __value_; | 
|  |  | 
|  | public: | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 __tuple_leaf& operator=(const __tuple_leaf&) = delete; | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf() noexcept(is_nothrow_default_constructible<_Hp>::value) : __value_() { | 
|  | static_assert(!is_reference<_Hp>::value, "Attempted to default construct a reference element in a tuple"); | 
|  | } | 
|  |  | 
|  | template <class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 0>, const _Alloc&) : __value_() { | 
|  | static_assert(!is_reference<_Hp>::value, "Attempted to default construct a reference element in a tuple"); | 
|  | } | 
|  |  | 
|  | template <class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a) | 
|  | : __value_(allocator_arg_t(), __a) { | 
|  | static_assert(!is_reference<_Hp>::value, "Attempted to default construct a reference element in a tuple"); | 
|  | } | 
|  |  | 
|  | template <class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a) : __value_(__a) { | 
|  | static_assert(!is_reference<_Hp>::value, "Attempted to default construct a reference element in a tuple"); | 
|  | } | 
|  |  | 
|  | template < | 
|  | class _Tp, | 
|  | __enable_if_t<_And<_IsNotSame<__remove_cvref_t<_Tp>, __tuple_leaf>, is_constructible<_Hp, _Tp> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __tuple_leaf(_Tp&& __t) noexcept(is_nothrow_constructible<_Hp, _Tp>::value) | 
|  | : __value_(std::forward<_Tp>(__t)) { | 
|  | static_assert(!__reference_constructs_from_temporary_v<_Hp, _Tp&&>, | 
|  | "Attempted construction of reference element binds to a temporary whose lifetime has ended"); | 
|  | } | 
|  |  | 
|  | template <class _Tp, class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __tuple_leaf(integral_constant<int, 0>, const _Alloc&, _Tp&& __t) | 
|  | : __value_(std::forward<_Tp>(__t)) { | 
|  | static_assert(!__reference_constructs_from_temporary_v<_Hp, _Tp&&>, | 
|  | "Attempted construction of reference element binds to a temporary whose lifetime has ended"); | 
|  | } | 
|  |  | 
|  | template <class _Tp, class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a, _Tp&& __t) | 
|  | : __value_(allocator_arg_t(), __a, std::forward<_Tp>(__t)) { | 
|  | static_assert(!is_reference<_Hp>::value, "Attempted to uses-allocator construct a reference element in a tuple"); | 
|  | } | 
|  |  | 
|  | template <class _Tp, class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a, _Tp&& __t) | 
|  | : __value_(std::forward<_Tp>(__t), __a) { | 
|  | static_assert(!is_reference<_Hp>::value, "Attempted to uses-allocator construct a reference element in a tuple"); | 
|  | } | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI __tuple_leaf(const __tuple_leaf& __t) = default; | 
|  | _LIBCPP_HIDE_FROM_ABI __tuple_leaf(__tuple_leaf&& __t)      = default; | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int | 
|  | swap(__tuple_leaf& __t) noexcept(__is_nothrow_swappable_v<__tuple_leaf>) { | 
|  | std::swap(*this, __t); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int swap(const __tuple_leaf& __t) const | 
|  | noexcept(__is_nothrow_swappable_v<const __tuple_leaf>) { | 
|  | std::swap(*this, __t); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Hp& get() _NOEXCEPT { return __value_; } | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const _Hp& get() const _NOEXCEPT { return __value_; } | 
|  | }; | 
|  |  | 
|  | template <size_t _Ip, class _Hp> | 
|  | class __tuple_leaf<_Ip, _Hp, true> : private __remove_cv_t<_Hp> { | 
|  | public: | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 __tuple_leaf& operator=(const __tuple_leaf&) = delete; | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf() noexcept(is_nothrow_default_constructible<_Hp>::value) {} | 
|  |  | 
|  | template <class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 0>, const _Alloc&) {} | 
|  |  | 
|  | template <class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a) | 
|  | : _Hp(allocator_arg_t(), __a) {} | 
|  |  | 
|  | template <class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a) : _Hp(__a) {} | 
|  |  | 
|  | template <class _Tp, | 
|  | __enable_if_t< _And< _IsNotSame<__remove_cvref_t<_Tp>, __tuple_leaf>, is_constructible<_Hp, _Tp> >::value, | 
|  | int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __tuple_leaf(_Tp&& __t) noexcept(is_nothrow_constructible<_Hp, _Tp>::value) | 
|  | : _Hp(std::forward<_Tp>(__t)) {} | 
|  |  | 
|  | template <class _Tp, class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit __tuple_leaf(integral_constant<int, 0>, const _Alloc&, _Tp&& __t) | 
|  | : _Hp(std::forward<_Tp>(__t)) {} | 
|  |  | 
|  | template <class _Tp, class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a, _Tp&& __t) | 
|  | : _Hp(allocator_arg_t(), __a, std::forward<_Tp>(__t)) {} | 
|  |  | 
|  | template <class _Tp, class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a, _Tp&& __t) | 
|  | : _Hp(std::forward<_Tp>(__t), __a) {} | 
|  |  | 
|  | __tuple_leaf(__tuple_leaf const&) = default; | 
|  | __tuple_leaf(__tuple_leaf&&)      = default; | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int | 
|  | swap(__tuple_leaf& __t) noexcept(__is_nothrow_swappable_v<__tuple_leaf>) { | 
|  | std::swap(*this, __t); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int swap(const __tuple_leaf& __rhs) const | 
|  | noexcept(__is_nothrow_swappable_v<const __tuple_leaf>) { | 
|  | std::swap(*this, __rhs); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Hp& get() _NOEXCEPT { return static_cast<_Hp&>(*this); } | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const _Hp& get() const _NOEXCEPT { | 
|  | return static_cast<const _Hp&>(*this); | 
|  | } | 
|  | }; | 
|  |  | 
|  | template <class... _Tp> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void __swallow(_Tp&&...) _NOEXCEPT {} | 
|  |  | 
|  | template <class _Tp> | 
|  | struct __all_default_constructible; | 
|  |  | 
|  | template <class... _Tp> | 
|  | struct __all_default_constructible<__tuple_types<_Tp...>> : __all<is_default_constructible<_Tp>::value...> {}; | 
|  |  | 
|  | // __tuple_impl | 
|  |  | 
|  | template <class _Indx, class... _Tp> | 
|  | struct __tuple_impl; | 
|  |  | 
|  | template <size_t... _Indx, class... _Tp> | 
|  | struct _LIBCPP_DECLSPEC_EMPTY_BASES | 
|  | __tuple_impl<__tuple_indices<_Indx...>, _Tp...> : public __tuple_leaf<_Indx, _Tp>... { | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr __tuple_impl() noexcept( | 
|  | __all<is_nothrow_default_constructible<_Tp>::value...>::value) {} | 
|  |  | 
|  | template <size_t... _Uf, class... _Tf, size_t... _Ul, class... _Tl, class... _Up> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __tuple_impl( | 
|  | __tuple_indices<_Uf...>, | 
|  | __tuple_types<_Tf...>, | 
|  | __tuple_indices<_Ul...>, | 
|  | __tuple_types<_Tl...>, | 
|  | _Up&&... __u) noexcept(__all<is_nothrow_constructible<_Tf, _Up>::value...>::value && | 
|  | __all<is_nothrow_default_constructible<_Tl>::value...>::value) | 
|  | : __tuple_leaf<_Uf, _Tf>(std::forward<_Up>(__u))..., __tuple_leaf<_Ul, _Tl>()... {} | 
|  |  | 
|  | template <class _Alloc, size_t... _Uf, class... _Tf, size_t... _Ul, class... _Tl, class... _Up> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __tuple_impl( | 
|  | allocator_arg_t, | 
|  | const _Alloc& __a, | 
|  | __tuple_indices<_Uf...>, | 
|  | __tuple_types<_Tf...>, | 
|  | __tuple_indices<_Ul...>, | 
|  | __tuple_types<_Tl...>, | 
|  | _Up&&... __u) | 
|  | : __tuple_leaf<_Uf, _Tf>(__uses_alloc_ctor<_Tf, _Alloc, _Up>(), __a, std::forward<_Up>(__u))..., | 
|  | __tuple_leaf<_Ul, _Tl>(__uses_alloc_ctor<_Tl, _Alloc>(), __a)... {} | 
|  |  | 
|  | template <class _Tuple, __enable_if_t<__tuple_constructible<_Tuple, tuple<_Tp...> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __tuple_impl(_Tuple&& __t) noexcept( | 
|  | (__all<is_nothrow_constructible< | 
|  | _Tp, | 
|  | typename tuple_element<_Indx, typename __make_tuple_types<_Tuple>::type>::type>::value...>::value)) | 
|  | : __tuple_leaf<_Indx, _Tp>( | 
|  | std::forward<typename tuple_element<_Indx, typename __make_tuple_types<_Tuple>::type>::type>( | 
|  | std::get<_Indx>(__t)))... {} | 
|  |  | 
|  | template <class _Alloc, class _Tuple, __enable_if_t<__tuple_constructible<_Tuple, tuple<_Tp...> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __tuple_impl(allocator_arg_t, const _Alloc& __a, _Tuple&& __t) | 
|  | : __tuple_leaf<_Indx, _Tp>( | 
|  | __uses_alloc_ctor<_Tp, | 
|  | _Alloc, | 
|  | typename tuple_element<_Indx, typename __make_tuple_types<_Tuple>::type>::type>(), | 
|  | __a, | 
|  | std::forward<typename tuple_element<_Indx, typename __make_tuple_types<_Tuple>::type>::type>( | 
|  | std::get<_Indx>(__t)))... {} | 
|  |  | 
|  | __tuple_impl(const __tuple_impl&) = default; | 
|  | __tuple_impl(__tuple_impl&&)      = default; | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void | 
|  | swap(__tuple_impl& __t) noexcept(__all<__is_nothrow_swappable_v<_Tp>...>::value) { | 
|  | std::__swallow(__tuple_leaf<_Indx, _Tp>::swap(static_cast<__tuple_leaf<_Indx, _Tp>&>(__t))...); | 
|  | } | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void swap(const __tuple_impl& __t) const | 
|  | noexcept(__all<__is_nothrow_swappable_v<const _Tp>...>::value) { | 
|  | std::__swallow(__tuple_leaf<_Indx, _Tp>::swap(static_cast<const __tuple_leaf<_Indx, _Tp>&>(__t))...); | 
|  | } | 
|  | }; | 
|  |  | 
|  | template <class _Dest, class _Source, size_t... _Np> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void | 
|  | __memberwise_copy_assign(_Dest& __dest, _Source const& __source, __tuple_indices<_Np...>) { | 
|  | std::__swallow(((std::get<_Np>(__dest) = std::get<_Np>(__source)), void(), 0)...); | 
|  | } | 
|  |  | 
|  | template <class _Dest, class _Source, class... _Up, size_t... _Np> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void | 
|  | __memberwise_forward_assign(_Dest& __dest, _Source&& __source, __tuple_types<_Up...>, __tuple_indices<_Np...>) { | 
|  | std::__swallow(((std::get<_Np>(__dest) = std::forward<_Up>(std::get<_Np>(__source))), void(), 0)...); | 
|  | } | 
|  |  | 
|  | template <class... _Tp> | 
|  | class _LIBCPP_NO_SPECIALIZATIONS tuple { | 
|  | typedef __tuple_impl<typename __make_tuple_indices<sizeof...(_Tp)>::type, _Tp...> _BaseT; | 
|  |  | 
|  | _BaseT __base_; | 
|  |  | 
|  | template <size_t _Jp, class... _Up> | 
|  | friend _LIBCPP_CONSTEXPR_SINCE_CXX14 typename tuple_element<_Jp, tuple<_Up...> >::type& get(tuple<_Up...>&) _NOEXCEPT; | 
|  | template <size_t _Jp, class... _Up> | 
|  | friend _LIBCPP_CONSTEXPR_SINCE_CXX14 const typename tuple_element<_Jp, tuple<_Up...> >::type& | 
|  | get(const tuple<_Up...>&) _NOEXCEPT; | 
|  | template <size_t _Jp, class... _Up> | 
|  | friend _LIBCPP_CONSTEXPR_SINCE_CXX14 typename tuple_element<_Jp, tuple<_Up...> >::type&& | 
|  | get(tuple<_Up...>&&) _NOEXCEPT; | 
|  | template <size_t _Jp, class... _Up> | 
|  | friend _LIBCPP_CONSTEXPR_SINCE_CXX14 const typename tuple_element<_Jp, tuple<_Up...> >::type&& | 
|  | get(const tuple<_Up...>&&) _NOEXCEPT; | 
|  |  | 
|  | public: | 
|  | using __trivially_relocatable _LIBCPP_NODEBUG = | 
|  | __conditional_t<_And<__libcpp_is_trivially_relocatable<_Tp>...>::value, tuple, void>; | 
|  | using __replaceable _LIBCPP_NODEBUG = __conditional_t<_And<__is_replaceable<_Tp>...>::value, tuple, void>; | 
|  |  | 
|  | // [tuple.cnstr] | 
|  |  | 
|  | // tuple() constructors (including allocator_arg_t variants) | 
|  | template <template <class...> class _IsImpDefault                = __is_implicitly_default_constructible, | 
|  | template <class...> class _IsDefault                   = is_default_constructible, | 
|  | __enable_if_t< _And< _IsDefault<_Tp>... >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(_Not<_Lazy<_And, _IsImpDefault<_Tp>...> >::value) | 
|  | tuple() noexcept(_And<is_nothrow_default_constructible<_Tp>...>::value) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | template <class...> class _IsImpDefault                = __is_implicitly_default_constructible, | 
|  | template <class...> class _IsDefault                   = is_default_constructible, | 
|  | __enable_if_t< _And< _IsDefault<_Tp>... >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit(_Not<_Lazy<_And, _IsImpDefault<_Tp>...> >::value) | 
|  | tuple(allocator_arg_t, _Alloc const& __a) | 
|  | : __base_(allocator_arg_t(), | 
|  | __a, | 
|  | __tuple_indices<>(), | 
|  | __tuple_types<>(), | 
|  | typename __make_tuple_indices<sizeof...(_Tp), 0>::type(), | 
|  | __tuple_types<_Tp...>()) {} | 
|  |  | 
|  | // tuple(const T&...) constructors (including allocator_arg_t variants) | 
|  | template <template <class...> class _And = _And, | 
|  | __enable_if_t< _And< _BoolConstant<sizeof...(_Tp) >= 1>, is_copy_constructible<_Tp>... >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(_Not<_Lazy<_And, is_convertible<const _Tp&, _Tp>...> >::value) | 
|  | tuple(const _Tp&... __t) noexcept(_And<is_nothrow_copy_constructible<_Tp>...>::value) | 
|  | : __base_(typename __make_tuple_indices<sizeof...(_Tp)>::type(), | 
|  | typename __make_tuple_types<tuple, sizeof...(_Tp)>::type(), | 
|  | typename __make_tuple_indices<0>::type(), | 
|  | typename __make_tuple_types<tuple, 0>::type(), | 
|  | __t...) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | template <class...> class _And = _And, | 
|  | __enable_if_t< _And< _BoolConstant<sizeof...(_Tp) >= 1>, is_copy_constructible<_Tp>... >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit(_Not<_Lazy<_And, is_convertible<const _Tp&, _Tp>...> >::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __a, const _Tp&... __t) | 
|  | : __base_(allocator_arg_t(), | 
|  | __a, | 
|  | typename __make_tuple_indices<sizeof...(_Tp)>::type(), | 
|  | typename __make_tuple_types<tuple, sizeof...(_Tp)>::type(), | 
|  | typename __make_tuple_indices<0>::type(), | 
|  | typename __make_tuple_types<tuple, 0>::type(), | 
|  | __t...) {} | 
|  |  | 
|  | // tuple(U&& ...) constructors (including allocator_arg_t variants) | 
|  | template <class... _Up> | 
|  | struct _IsThisTuple : false_type {}; | 
|  | template <class _Up> | 
|  | struct _IsThisTuple<_Up> : is_same<__remove_cvref_t<_Up>, tuple> {}; | 
|  |  | 
|  | template <class... _Up> | 
|  | struct _EnableUTypesCtor | 
|  | : _And< _BoolConstant<sizeof...(_Tp) >= 1>, | 
|  | _Not<_IsThisTuple<_Up...> >, // extension to allow mis-behaved user constructors | 
|  | is_constructible<_Tp, _Up>... > {}; | 
|  |  | 
|  | template <class... _Up, | 
|  | __enable_if_t< _And< _BoolConstant<sizeof...(_Up) == sizeof...(_Tp)>, _EnableUTypesCtor<_Up...> >::value, | 
|  | int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(_Not<_Lazy<_And, is_convertible<_Up, _Tp>...> >::value) | 
|  | tuple(_Up&&... __u) noexcept(_And<is_nothrow_constructible<_Tp, _Up>...>::value) | 
|  | : __base_(typename __make_tuple_indices<sizeof...(_Up)>::type(), | 
|  | typename __make_tuple_types<tuple, sizeof...(_Up)>::type(), | 
|  | typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type(), | 
|  | typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type(), | 
|  | std::forward<_Up>(__u)...) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | class... _Up, | 
|  | __enable_if_t< _And< _BoolConstant<sizeof...(_Up) == sizeof...(_Tp)>, _EnableUTypesCtor<_Up...> >::value, | 
|  | int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit(_Not<_Lazy<_And, is_convertible<_Up, _Tp>...> >::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u) | 
|  | : __base_(allocator_arg_t(), | 
|  | __a, | 
|  | typename __make_tuple_indices<sizeof...(_Up)>::type(), | 
|  | typename __make_tuple_types<tuple, sizeof...(_Up)>::type(), | 
|  | typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type(), | 
|  | typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type(), | 
|  | std::forward<_Up>(__u)...) {} | 
|  |  | 
|  | // Copy and move constructors (including the allocator_arg_t variants) | 
|  | tuple(const tuple&) = default; | 
|  | tuple(tuple&&)      = default; | 
|  |  | 
|  | template <class _Alloc, | 
|  | template <class...> class _And                                  = _And, | 
|  | __enable_if_t< _And<is_copy_constructible<_Tp>...>::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple(allocator_arg_t, const _Alloc& __alloc, const tuple& __t) | 
|  | : __base_(allocator_arg_t(), __alloc, __t) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | template <class...> class _And                                  = _And, | 
|  | __enable_if_t< _And<is_move_constructible<_Tp>...>::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple(allocator_arg_t, const _Alloc& __alloc, tuple&& __t) | 
|  | : __base_(allocator_arg_t(), __alloc, std::move(__t)) {} | 
|  |  | 
|  | // tuple(const tuple<U...>&) constructors (including allocator_arg_t variants) | 
|  |  | 
|  | template <class _OtherTuple, class _DecayedOtherTuple = __remove_cvref_t<_OtherTuple>, class = void> | 
|  | struct _EnableCtorFromUTypesTuple : false_type {}; | 
|  |  | 
|  | template <class _OtherTuple, class... _Up> | 
|  | struct _EnableCtorFromUTypesTuple< | 
|  | _OtherTuple, | 
|  | tuple<_Up...>, | 
|  | // the length of the packs needs to checked first otherwise the 2 packs cannot be expanded simultaneously below | 
|  | __enable_if_t<sizeof...(_Up) == sizeof...(_Tp)>> | 
|  | : _And< | 
|  | // the two conditions below are not in spec. The purpose is to disable the UTypes Ctor when copy/move Ctor | 
|  | // can work. Otherwise, is_constructible can trigger hard error in those cases | 
|  | // https://godbolt.org/z/M94cGdKcE | 
|  | _Not<is_same<_OtherTuple, const tuple&> >, | 
|  | _Not<is_same<_OtherTuple, tuple&&> >, | 
|  | is_constructible<_Tp, __copy_cvref_t<_OtherTuple, _Up> >..., | 
|  | _Lazy<_Or, | 
|  | _BoolConstant<sizeof...(_Tp) != 1>, | 
|  | // _Tp and _Up are 1-element packs - the pack expansions look | 
|  | // weird to avoid tripping up the type traits in degenerate cases | 
|  | _Lazy<_And, | 
|  | _Not<is_same<_Tp, _Up> >..., | 
|  | _Not<is_convertible<_OtherTuple, _Tp> >..., | 
|  | _Not<is_constructible<_Tp, _OtherTuple> >... > > > {}; | 
|  |  | 
|  | template <class... _Up, __enable_if_t< _And< _EnableCtorFromUTypesTuple<const tuple<_Up...>&> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(_Not<_Lazy<_And, is_convertible<const _Up&, _Tp>...> >::value) | 
|  | tuple(const tuple<_Up...>& __t) noexcept(_And<is_nothrow_constructible<_Tp, const _Up&>...>::value) | 
|  | : __base_(__t) {} | 
|  |  | 
|  | template <class... _Up, | 
|  | class _Alloc, | 
|  | __enable_if_t< _And< _EnableCtorFromUTypesTuple<const tuple<_Up...>&> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit(_Not<_Lazy<_And, is_convertible<const _Up&, _Tp>...> >::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __a, const tuple<_Up...>& __t) | 
|  | : __base_(allocator_arg_t(), __a, __t) {} | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | // tuple(tuple<U...>&) constructors (including allocator_arg_t variants) | 
|  |  | 
|  | template <class... _Up, enable_if_t< _EnableCtorFromUTypesTuple<tuple<_Up...>&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(!_Lazy<_And, is_convertible<_Up&, _Tp>...>::value) tuple(tuple<_Up...>& __t) | 
|  | : __base_(__t) {} | 
|  |  | 
|  | template <class _Alloc, class... _Up, enable_if_t< _EnableCtorFromUTypesTuple<tuple<_Up...>&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(!_Lazy<_And, is_convertible<_Up&, _Tp>...>::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __alloc, tuple<_Up...>& __t) | 
|  | : __base_(allocator_arg_t(), __alloc, __t) {} | 
|  | #    endif // _LIBCPP_STD_VER >= 23 | 
|  |  | 
|  | // tuple(tuple<U...>&&) constructors (including allocator_arg_t variants) | 
|  | template <class... _Up, __enable_if_t< _And< _EnableCtorFromUTypesTuple<tuple<_Up...>&&> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(_Not<_Lazy<_And, is_convertible<_Up, _Tp>...> >::value) | 
|  | tuple(tuple<_Up...>&& __t) noexcept(_And<is_nothrow_constructible<_Tp, _Up>...>::value) | 
|  | : __base_(std::move(__t)) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | class... _Up, | 
|  | __enable_if_t< _And< _EnableCtorFromUTypesTuple<tuple<_Up...>&&> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit(_Not<_Lazy<_And, is_convertible<_Up, _Tp>...> >::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __a, tuple<_Up...>&& __t) | 
|  | : __base_(allocator_arg_t(), __a, std::move(__t)) {} | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | // tuple(const tuple<U...>&&) constructors (including allocator_arg_t variants) | 
|  |  | 
|  | template <class... _Up, enable_if_t< _EnableCtorFromUTypesTuple<const tuple<_Up...>&&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(!_Lazy<_And, is_convertible<const _Up&&, _Tp>...>::value) | 
|  | tuple(const tuple<_Up...>&& __t) | 
|  | : __base_(std::move(__t)) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | class... _Up, | 
|  | enable_if_t< _EnableCtorFromUTypesTuple<const tuple<_Up...>&&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(!_Lazy<_And, is_convertible<const _Up&&, _Tp>...>::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __alloc, const tuple<_Up...>&& __t) | 
|  | : __base_(allocator_arg_t(), __alloc, std::move(__t)) {} | 
|  | #    endif // _LIBCPP_STD_VER >= 23 | 
|  |  | 
|  | // tuple(const pair<U1, U2>&) constructors (including allocator_arg_t variants) | 
|  |  | 
|  | template <template <class...> class _Pred, | 
|  | class _Pair, | 
|  | class _DecayedPair = __remove_cvref_t<_Pair>, | 
|  | class _Tuple       = tuple> | 
|  | struct _CtorPredicateFromPair : false_type {}; | 
|  |  | 
|  | template <template <class...> class _Pred, class _Pair, class _Up1, class _Up2, class _Tp1, class _Tp2> | 
|  | struct _CtorPredicateFromPair<_Pred, _Pair, pair<_Up1, _Up2>, tuple<_Tp1, _Tp2> > | 
|  | : _And< _Pred<_Tp1, __copy_cvref_t<_Pair, _Up1> >, _Pred<_Tp2, __copy_cvref_t<_Pair, _Up2> > > {}; | 
|  |  | 
|  | template <class _Pair> | 
|  | struct _EnableCtorFromPair : _CtorPredicateFromPair<is_constructible, _Pair> {}; | 
|  |  | 
|  | template <class _Pair> | 
|  | struct _NothrowConstructibleFromPair : _CtorPredicateFromPair<is_nothrow_constructible, _Pair> {}; | 
|  |  | 
|  | template <class _Pair, class _DecayedPair = __remove_cvref_t<_Pair>, class _Tuple = tuple> | 
|  | struct _BothImplicitlyConvertible : false_type {}; | 
|  |  | 
|  | template <class _Pair, class _Up1, class _Up2, class _Tp1, class _Tp2> | 
|  | struct _BothImplicitlyConvertible<_Pair, pair<_Up1, _Up2>, tuple<_Tp1, _Tp2> > | 
|  | : _And< is_convertible<__copy_cvref_t<_Pair, _Up1>, _Tp1>, is_convertible<__copy_cvref_t<_Pair, _Up2>, _Tp2> > {}; | 
|  |  | 
|  | template <class _Up1, | 
|  | class _Up2, | 
|  | template <class...> class _And                                                   = _And, | 
|  | __enable_if_t< _And< _EnableCtorFromPair<const pair<_Up1, _Up2>&> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(_Not<_BothImplicitlyConvertible<const pair<_Up1, _Up2>&> >::value) | 
|  | tuple(const pair<_Up1, _Up2>& __p) noexcept(_NothrowConstructibleFromPair<const pair<_Up1, _Up2>&>::value) | 
|  | : __base_(__p) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | class _Up1, | 
|  | class _Up2, | 
|  | template <class...> class _And                                                   = _And, | 
|  | __enable_if_t< _And< _EnableCtorFromPair<const pair<_Up1, _Up2>&> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit(_Not<_BothImplicitlyConvertible<const pair<_Up1, _Up2>&> >::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __a, const pair<_Up1, _Up2>& __p) | 
|  | : __base_(allocator_arg_t(), __a, __p) {} | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | // tuple(pair<U1, U2>&) constructors (including allocator_arg_t variants) | 
|  |  | 
|  | template <class _U1, class _U2, enable_if_t< _EnableCtorFromPair<pair<_U1, _U2>&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(!_BothImplicitlyConvertible<pair<_U1, _U2>&>::value) | 
|  | tuple(pair<_U1, _U2>& __p) | 
|  | : __base_(__p) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | class _U1, | 
|  | class _U2, | 
|  | enable_if_t< _EnableCtorFromPair<std::pair<_U1, _U2>&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(!_BothImplicitlyConvertible<pair<_U1, _U2>&>::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __alloc, pair<_U1, _U2>& __p) | 
|  | : __base_(allocator_arg_t(), __alloc, __p) {} | 
|  | #    endif | 
|  |  | 
|  | // tuple(pair<U1, U2>&&) constructors (including allocator_arg_t variants) | 
|  |  | 
|  | template <class _Up1, | 
|  | class _Up2, | 
|  | template <class...> class _And                                              = _And, | 
|  | __enable_if_t< _And< _EnableCtorFromPair<pair<_Up1, _Up2>&&> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(_Not<_BothImplicitlyConvertible<pair<_Up1, _Up2>&&> >::value) | 
|  | tuple(pair<_Up1, _Up2>&& __p) noexcept(_NothrowConstructibleFromPair<pair<_Up1, _Up2>&&>::value) | 
|  | : __base_(std::move(__p)) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | class _Up1, | 
|  | class _Up2, | 
|  | template <class...> class _And                                              = _And, | 
|  | __enable_if_t< _And< _EnableCtorFromPair<pair<_Up1, _Up2>&&> >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI | 
|  | _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit(_Not<_BothImplicitlyConvertible<pair<_Up1, _Up2>&&> >::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __a, pair<_Up1, _Up2>&& __p) | 
|  | : __base_(allocator_arg_t(), __a, std::move(__p)) {} | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | // tuple(const pair<U1, U2>&&) constructors (including allocator_arg_t variants) | 
|  |  | 
|  | template <class _U1, class _U2, enable_if_t< _EnableCtorFromPair<const pair<_U1, _U2>&&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(!_BothImplicitlyConvertible<const pair<_U1, _U2>&&>::value) | 
|  | tuple(const pair<_U1, _U2>&& __p) | 
|  | : __base_(std::move(__p)) {} | 
|  |  | 
|  | template <class _Alloc, | 
|  | class _U1, | 
|  | class _U2, | 
|  | enable_if_t< _EnableCtorFromPair<const pair<_U1, _U2>&&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr explicit(!_BothImplicitlyConvertible<const pair<_U1, _U2>&&>::value) | 
|  | tuple(allocator_arg_t, const _Alloc& __alloc, const pair<_U1, _U2>&& __p) | 
|  | : __base_(allocator_arg_t(), __alloc, std::move(__p)) {} | 
|  | #    endif // _LIBCPP_STD_VER >= 23 | 
|  |  | 
|  | // [tuple.assign] | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple& | 
|  | operator=(_If<_And<is_copy_assignable<_Tp>...>::value, tuple, __nat> const& __tuple) noexcept( | 
|  | _And<is_nothrow_copy_assignable<_Tp>...>::value) { | 
|  | std::__memberwise_copy_assign(*this, __tuple, typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr const tuple& operator=(tuple const& __tuple) const | 
|  | requires(_And<is_copy_assignable<const _Tp>...>::value) | 
|  | { | 
|  | std::__memberwise_copy_assign(*this, __tuple, typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr const tuple& operator=(tuple&& __tuple) const | 
|  | requires(_And<is_assignable<const _Tp&, _Tp>...>::value) | 
|  | { | 
|  | std::__memberwise_forward_assign( | 
|  | *this, std::move(__tuple), __tuple_types<_Tp...>(), typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  | #    endif // _LIBCPP_STD_VER >= 23 | 
|  |  | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple& | 
|  | operator=(_If<_And<is_move_assignable<_Tp>...>::value, tuple, __nat>&& __tuple) noexcept( | 
|  | _And<is_nothrow_move_assignable<_Tp>...>::value) { | 
|  | std::__memberwise_forward_assign( | 
|  | *this, std::move(__tuple), __tuple_types<_Tp...>(), typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | template < | 
|  | class... _Up, | 
|  | __enable_if_t< _And< _BoolConstant<sizeof...(_Tp) == sizeof...(_Up)>, is_assignable<_Tp&, _Up const&>... >::value, | 
|  | int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple& | 
|  | operator=(tuple<_Up...> const& __tuple) noexcept(_And<is_nothrow_assignable<_Tp&, _Up const&>...>::value) { | 
|  | std::__memberwise_copy_assign(*this, __tuple, typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | template <class... _Up, | 
|  | __enable_if_t< _And< _BoolConstant<sizeof...(_Tp) == sizeof...(_Up)>, is_assignable<_Tp&, _Up>... >::value, | 
|  | int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple& | 
|  | operator=(tuple<_Up...>&& __tuple) noexcept(_And<is_nothrow_assignable<_Tp&, _Up>...>::value) { | 
|  | std::__memberwise_forward_assign( | 
|  | *this, std::move(__tuple), __tuple_types<_Up...>(), typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | template <class... _UTypes, | 
|  | enable_if_t< _And<_BoolConstant<sizeof...(_Tp) == sizeof...(_UTypes)>, | 
|  | is_assignable<const _Tp&, const _UTypes&>...>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr const tuple& operator=(const tuple<_UTypes...>& __u) const { | 
|  | std::__memberwise_copy_assign(*this, __u, typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | template <class... _UTypes, | 
|  | enable_if_t< _And<_BoolConstant<sizeof...(_Tp) == sizeof...(_UTypes)>, | 
|  | is_assignable<const _Tp&, _UTypes>...>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr const tuple& operator=(tuple<_UTypes...>&& __u) const { | 
|  | std::__memberwise_forward_assign( | 
|  | *this, __u, __tuple_types<_UTypes...>(), typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  | #    endif // _LIBCPP_STD_VER >= 23 | 
|  |  | 
|  | template <template <class...> class _Pred, | 
|  | bool _Const, | 
|  | class _Pair, | 
|  | class _DecayedPair = __remove_cvref_t<_Pair>, | 
|  | class _Tuple       = tuple> | 
|  | struct _AssignPredicateFromPair : false_type {}; | 
|  |  | 
|  | template <template <class...> class _Pred, bool _Const, class _Pair, class _Up1, class _Up2, class _Tp1, class _Tp2> | 
|  | struct _AssignPredicateFromPair<_Pred, _Const, _Pair, pair<_Up1, _Up2>, tuple<_Tp1, _Tp2> > | 
|  | : _And<_Pred<__maybe_const<_Const, _Tp1>&, __copy_cvref_t<_Pair, _Up1> >, | 
|  | _Pred<__maybe_const<_Const, _Tp2>&, __copy_cvref_t<_Pair, _Up2> > > {}; | 
|  |  | 
|  | template <bool _Const, class _Pair> | 
|  | struct _EnableAssignFromPair : _AssignPredicateFromPair<is_assignable, _Const, _Pair> {}; | 
|  |  | 
|  | template <bool _Const, class _Pair> | 
|  | struct _NothrowAssignFromPair : _AssignPredicateFromPair<is_nothrow_assignable, _Const, _Pair> {}; | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | template <class _U1, class _U2, enable_if_t< _EnableAssignFromPair<true, const pair<_U1, _U2>&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr const tuple& operator=(const pair<_U1, _U2>& __pair) const | 
|  | noexcept(_NothrowAssignFromPair<true, const pair<_U1, _U2>&>::value) { | 
|  | std::get<0>(*this) = __pair.first; | 
|  | std::get<1>(*this) = __pair.second; | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | template <class _U1, class _U2, enable_if_t< _EnableAssignFromPair<true, pair<_U1, _U2>&&>::value>* = nullptr> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr const tuple& operator=(pair<_U1, _U2>&& __pair) const | 
|  | noexcept(_NothrowAssignFromPair<true, pair<_U1, _U2>&&>::value) { | 
|  | std::get<0>(*this) = std::move(__pair.first); | 
|  | std::get<1>(*this) = std::move(__pair.second); | 
|  | return *this; | 
|  | } | 
|  | #    endif // _LIBCPP_STD_VER >= 23 | 
|  |  | 
|  | template <class _Up1, | 
|  | class _Up2, | 
|  | __enable_if_t< _EnableAssignFromPair<false, pair<_Up1, _Up2> const&>::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple& | 
|  | operator=(pair<_Up1, _Up2> const& __pair) noexcept(_NothrowAssignFromPair<false, pair<_Up1, _Up2> const&>::value) { | 
|  | std::get<0>(*this) = __pair.first; | 
|  | std::get<1>(*this) = __pair.second; | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | template <class _Up1, class _Up2, __enable_if_t< _EnableAssignFromPair<false, pair<_Up1, _Up2>&&>::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple& | 
|  | operator=(pair<_Up1, _Up2>&& __pair) noexcept(_NothrowAssignFromPair<false, pair<_Up1, _Up2>&&>::value) { | 
|  | std::get<0>(*this) = std::forward<_Up1>(__pair.first); | 
|  | std::get<1>(*this) = std::forward<_Up2>(__pair.second); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | // EXTENSION | 
|  | template < | 
|  | class _Up, | 
|  | size_t _Np, | 
|  | __enable_if_t< _And< _BoolConstant<_Np == sizeof...(_Tp)>, is_assignable<_Tp&, _Up const&>... >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple& | 
|  | operator=(array<_Up, _Np> const& __array) noexcept(_And<is_nothrow_assignable<_Tp&, _Up const&>...>::value) { | 
|  | std::__memberwise_copy_assign(*this, __array, typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | // EXTENSION | 
|  | template <class _Up, | 
|  | size_t _Np, | 
|  | class = void, | 
|  | __enable_if_t< _And< _BoolConstant<_Np == sizeof...(_Tp)>, is_assignable<_Tp&, _Up>... >::value, int> = 0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple& | 
|  | operator=(array<_Up, _Np>&& __array) noexcept(_And<is_nothrow_assignable<_Tp&, _Up>...>::value) { | 
|  | std::__memberwise_forward_assign( | 
|  | *this, | 
|  | std::move(__array), | 
|  | __tuple_types<_If<true, _Up, _Tp>...>(), | 
|  | typename __make_tuple_indices<sizeof...(_Tp)>::type()); | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | // [tuple.swap] | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void | 
|  | swap(tuple& __t) noexcept(__all<__is_nothrow_swappable_v<_Tp>...>::value) { | 
|  | __base_.swap(__t.__base_); | 
|  | } | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr void swap(const tuple& __t) const | 
|  | noexcept(__all<is_nothrow_swappable_v<const _Tp&>...>::value) { | 
|  | __base_.swap(__t.__base_); | 
|  | } | 
|  | #    endif // _LIBCPP_STD_VER >= 23 | 
|  | }; | 
|  |  | 
|  | _LIBCPP_DIAGNOSTIC_PUSH | 
|  | #    if __has_warning("-Winvalid-specialization") | 
|  | _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Winvalid-specialization") | 
|  | #    endif | 
|  | template <> | 
|  | class tuple<> { | 
|  | public: | 
|  | constexpr tuple() _NOEXCEPT = default; | 
|  | template <class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple(allocator_arg_t, const _Alloc&) _NOEXCEPT {} | 
|  | template <class _Alloc> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple(allocator_arg_t, const _Alloc&, const tuple&) _NOEXCEPT {} | 
|  | template <class _Up> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple(array<_Up, 0>) _NOEXCEPT {} | 
|  | template <class _Alloc, class _Up> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple(allocator_arg_t, const _Alloc&, array<_Up, 0>) _NOEXCEPT {} | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(tuple&) _NOEXCEPT {} | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr void swap(const tuple&) const noexcept {} | 
|  | #    endif | 
|  | }; | 
|  | _LIBCPP_DIAGNOSTIC_POP | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | template <class... _TTypes, class... _UTypes, template <class> class _TQual, template <class> class _UQual> | 
|  | requires requires { typename tuple<common_reference_t<_TQual<_TTypes>, _UQual<_UTypes>>...>; } | 
|  | struct basic_common_reference<tuple<_TTypes...>, tuple<_UTypes...>, _TQual, _UQual> { | 
|  | using type _LIBCPP_NODEBUG = tuple<common_reference_t<_TQual<_TTypes>, _UQual<_UTypes>>...>; | 
|  | }; | 
|  |  | 
|  | template <class... _TTypes, class... _UTypes> | 
|  | requires requires { typename tuple<common_type_t<_TTypes, _UTypes>...>; } | 
|  | struct common_type<tuple<_TTypes...>, tuple<_UTypes...>> { | 
|  | using type _LIBCPP_NODEBUG = tuple<common_type_t<_TTypes, _UTypes>...>; | 
|  | }; | 
|  | #    endif // _LIBCPP_STD_VER >= 23 | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 17 | 
|  | template <class... _Tp> | 
|  | tuple(_Tp...) -> tuple<_Tp...>; | 
|  | template <class _Tp1, class _Tp2> | 
|  | tuple(pair<_Tp1, _Tp2>) -> tuple<_Tp1, _Tp2>; | 
|  | template <class _Alloc, class... _Tp> | 
|  | tuple(allocator_arg_t, _Alloc, _Tp...) -> tuple<_Tp...>; | 
|  | template <class _Alloc, class _Tp1, class _Tp2> | 
|  | tuple(allocator_arg_t, _Alloc, pair<_Tp1, _Tp2>) -> tuple<_Tp1, _Tp2>; | 
|  | template <class _Alloc, class... _Tp> | 
|  | tuple(allocator_arg_t, _Alloc, tuple<_Tp...>) -> tuple<_Tp...>; | 
|  | #    endif | 
|  |  | 
|  | template <class... _Tp, __enable_if_t<__all<__is_swappable_v<_Tp>...>::value, int> = 0> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void | 
|  | swap(tuple<_Tp...>& __t, tuple<_Tp...>& __u) noexcept(__all<__is_nothrow_swappable_v<_Tp>...>::value) { | 
|  | __t.swap(__u); | 
|  | } | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 23 | 
|  | template <class... _Tp> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<__all<is_swappable_v<const _Tp>...>::value, void> | 
|  | swap(const tuple<_Tp...>& __lhs, | 
|  | const tuple<_Tp...>& __rhs) noexcept(__all<is_nothrow_swappable_v<const _Tp>...>::value) { | 
|  | __lhs.swap(__rhs); | 
|  | } | 
|  | #    endif | 
|  |  | 
|  | // get | 
|  |  | 
|  | template <size_t _Ip, class... _Tp> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename tuple_element<_Ip, tuple<_Tp...> >::type& | 
|  | get(tuple<_Tp...>& __t) _NOEXCEPT { | 
|  | using type _LIBCPP_NODEBUG = typename tuple_element<_Ip, tuple<_Tp...> >::type; | 
|  | return static_cast<__tuple_leaf<_Ip, type>&>(__t.__base_).get(); | 
|  | } | 
|  |  | 
|  | template <size_t _Ip, class... _Tp> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const typename tuple_element<_Ip, tuple<_Tp...> >::type& | 
|  | get(const tuple<_Tp...>& __t) _NOEXCEPT { | 
|  | using type _LIBCPP_NODEBUG = typename tuple_element<_Ip, tuple<_Tp...> >::type; | 
|  | return static_cast<const __tuple_leaf<_Ip, type>&>(__t.__base_).get(); | 
|  | } | 
|  |  | 
|  | template <size_t _Ip, class... _Tp> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename tuple_element<_Ip, tuple<_Tp...> >::type&& | 
|  | get(tuple<_Tp...>&& __t) _NOEXCEPT { | 
|  | using type _LIBCPP_NODEBUG = typename tuple_element<_Ip, tuple<_Tp...> >::type; | 
|  | return static_cast<type&&>(static_cast<__tuple_leaf<_Ip, type>&&>(__t.__base_).get()); | 
|  | } | 
|  |  | 
|  | template <size_t _Ip, class... _Tp> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const typename tuple_element<_Ip, tuple<_Tp...> >::type&& | 
|  | get(const tuple<_Tp...>&& __t) _NOEXCEPT { | 
|  | using type _LIBCPP_NODEBUG = typename tuple_element<_Ip, tuple<_Tp...> >::type; | 
|  | return static_cast<const type&&>(static_cast<const __tuple_leaf<_Ip, type>&&>(__t.__base_).get()); | 
|  | } | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 14 | 
|  |  | 
|  | template <class _T1, class... _Args> | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr _T1& get(tuple<_Args...>& __tup) noexcept { | 
|  | return std::get<__find_exactly_one_t<_T1, _Args...>::value>(__tup); | 
|  | } | 
|  |  | 
|  | template <class _T1, class... _Args> | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr _T1 const& get(tuple<_Args...> const& __tup) noexcept { | 
|  | return std::get<__find_exactly_one_t<_T1, _Args...>::value>(__tup); | 
|  | } | 
|  |  | 
|  | template <class _T1, class... _Args> | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr _T1&& get(tuple<_Args...>&& __tup) noexcept { | 
|  | return std::get<__find_exactly_one_t<_T1, _Args...>::value>(std::move(__tup)); | 
|  | } | 
|  |  | 
|  | template <class _T1, class... _Args> | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr _T1 const&& get(tuple<_Args...> const&& __tup) noexcept { | 
|  | return std::get<__find_exactly_one_t<_T1, _Args...>::value>(std::move(__tup)); | 
|  | } | 
|  |  | 
|  | #    endif | 
|  |  | 
|  | // tie | 
|  |  | 
|  | template <class... _Tp> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 tuple<_Tp&...> tie(_Tp&... __t) _NOEXCEPT { | 
|  | return tuple<_Tp&...>(__t...); | 
|  | } | 
|  |  | 
|  | template <class... _Tp> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 tuple<__unwrap_ref_decay_t<_Tp>...> | 
|  | make_tuple(_Tp&&... __t) { | 
|  | return tuple<__unwrap_ref_decay_t<_Tp>...>(std::forward<_Tp>(__t)...); | 
|  | } | 
|  |  | 
|  | template <class... _Tp> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 tuple<_Tp&&...> forward_as_tuple(_Tp&&... __t) _NOEXCEPT { | 
|  | return tuple<_Tp&&...>(std::forward<_Tp>(__t)...); | 
|  | } | 
|  |  | 
|  | template <size_t _Ip> | 
|  | struct __tuple_equal { | 
|  | template <class _Tp, class _Up> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(const _Tp& __x, const _Up& __y) { | 
|  | return __tuple_equal<_Ip - 1>()(__x, __y) && std::get<_Ip - 1>(__x) == std::get<_Ip - 1>(__y); | 
|  | } | 
|  | }; | 
|  |  | 
|  | template <> | 
|  | struct __tuple_equal<0> { | 
|  | template <class _Tp, class _Up> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(const _Tp&, const _Up&) { | 
|  | return true; | 
|  | } | 
|  | }; | 
|  |  | 
|  | template <class... _Tp, class... _Up> | 
|  | #    if _LIBCPP_STD_VER >= 26 | 
|  | requires(__all<requires(const _Tp& __t, const _Up& __u) { | 
|  | { __t == __u } -> __boolean_testable; | 
|  | }...>::value && (sizeof...(_Tp) == sizeof...(_Up))) | 
|  | #    endif | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool | 
|  | operator==(const tuple<_Tp...>& __x, const tuple<_Up...>& __y) { | 
|  | static_assert(sizeof...(_Tp) == sizeof...(_Up), "Can't compare tuples of different sizes"); | 
|  | return __tuple_equal<sizeof...(_Tp)>()(__x, __y); | 
|  | } | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 20 | 
|  |  | 
|  | // operator<=> | 
|  |  | 
|  | template <class... _Tp, class... _Up, size_t... _Is> | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr auto | 
|  | __tuple_compare_three_way(const tuple<_Tp...>& __x, const tuple<_Up...>& __y, index_sequence<_Is...>) { | 
|  | common_comparison_category_t<__synth_three_way_result<_Tp, _Up>...> __result = strong_ordering::equal; | 
|  | static_cast<void>( | 
|  | ((__result = std::__synth_three_way(std::get<_Is>(__x), std::get<_Is>(__y)), __result != 0) || ...)); | 
|  | return __result; | 
|  | } | 
|  |  | 
|  | template <class... _Tp, class... _Up> | 
|  | requires(sizeof...(_Tp) == sizeof...(_Up)) | 
|  | _LIBCPP_HIDE_FROM_ABI constexpr common_comparison_category_t<__synth_three_way_result<_Tp, _Up>...> | 
|  | operator<=>(const tuple<_Tp...>& __x, const tuple<_Up...>& __y) { | 
|  | return std::__tuple_compare_three_way(__x, __y, index_sequence_for<_Tp...>{}); | 
|  | } | 
|  |  | 
|  | #    else // _LIBCPP_STD_VER >= 20 | 
|  |  | 
|  | template <class... _Tp, class... _Up> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool | 
|  | operator!=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y) { | 
|  | return !(__x == __y); | 
|  | } | 
|  |  | 
|  | template <size_t _Ip> | 
|  | struct __tuple_less { | 
|  | template <class _Tp, class _Up> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(const _Tp& __x, const _Up& __y) { | 
|  | const size_t __idx = tuple_size<_Tp>::value - _Ip; | 
|  | if (std::get<__idx>(__x) < std::get<__idx>(__y)) | 
|  | return true; | 
|  | if (std::get<__idx>(__y) < std::get<__idx>(__x)) | 
|  | return false; | 
|  | return __tuple_less<_Ip - 1>()(__x, __y); | 
|  | } | 
|  | }; | 
|  |  | 
|  | template <> | 
|  | struct __tuple_less<0> { | 
|  | template <class _Tp, class _Up> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(const _Tp&, const _Up&) { | 
|  | return false; | 
|  | } | 
|  | }; | 
|  |  | 
|  | template <class... _Tp, class... _Up> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool | 
|  | operator<(const tuple<_Tp...>& __x, const tuple<_Up...>& __y) { | 
|  | static_assert(sizeof...(_Tp) == sizeof...(_Up), "Can't compare tuples of different sizes"); | 
|  | return __tuple_less<sizeof...(_Tp)>()(__x, __y); | 
|  | } | 
|  |  | 
|  | template <class... _Tp, class... _Up> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool | 
|  | operator>(const tuple<_Tp...>& __x, const tuple<_Up...>& __y) { | 
|  | return __y < __x; | 
|  | } | 
|  |  | 
|  | template <class... _Tp, class... _Up> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool | 
|  | operator>=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y) { | 
|  | return !(__x < __y); | 
|  | } | 
|  |  | 
|  | template <class... _Tp, class... _Up> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool | 
|  | operator<=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y) { | 
|  | return !(__y < __x); | 
|  | } | 
|  |  | 
|  | #    endif // _LIBCPP_STD_VER >= 20 | 
|  |  | 
|  | // tuple_cat | 
|  |  | 
|  | template <class _Tp, class _Up> | 
|  | struct __tuple_cat_type; | 
|  |  | 
|  | template <class... _Ttypes, class... _Utypes> | 
|  | struct __tuple_cat_type<tuple<_Ttypes...>, __tuple_types<_Utypes...> > { | 
|  | using type _LIBCPP_NODEBUG = tuple<_Ttypes..., _Utypes...>; | 
|  | }; | 
|  |  | 
|  | template <class _ResultTuple, bool _Is_Tuple0TupleLike, class... _Tuples> | 
|  | struct __tuple_cat_return_1 {}; | 
|  |  | 
|  | template <class... _Types, class _Tuple0> | 
|  | struct __tuple_cat_return_1<tuple<_Types...>, true, _Tuple0> { | 
|  | using type _LIBCPP_NODEBUG = | 
|  | typename __tuple_cat_type< tuple<_Types...>, | 
|  | typename __make_tuple_types<__remove_cvref_t<_Tuple0> >::type >::type; | 
|  | }; | 
|  |  | 
|  | template <class... _Types, class _Tuple0, class _Tuple1, class... _Tuples> | 
|  | struct __tuple_cat_return_1<tuple<_Types...>, true, _Tuple0, _Tuple1, _Tuples...> | 
|  | : public __tuple_cat_return_1< | 
|  | typename __tuple_cat_type< tuple<_Types...>, | 
|  | typename __make_tuple_types<__remove_cvref_t<_Tuple0> >::type >::type, | 
|  | __tuple_like_ext<__libcpp_remove_reference_t<_Tuple1> >::value, | 
|  | _Tuple1, | 
|  | _Tuples...> {}; | 
|  |  | 
|  | template <class... _Tuples> | 
|  | struct __tuple_cat_return; | 
|  |  | 
|  | template <class _Tuple0, class... _Tuples> | 
|  | struct __tuple_cat_return<_Tuple0, _Tuples...> | 
|  | : public __tuple_cat_return_1<tuple<>, | 
|  | __tuple_like_ext<__libcpp_remove_reference_t<_Tuple0> >::value, | 
|  | _Tuple0, | 
|  | _Tuples...> {}; | 
|  |  | 
|  | template <> | 
|  | struct __tuple_cat_return<> { | 
|  | using type _LIBCPP_NODEBUG = tuple<>; | 
|  | }; | 
|  |  | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 tuple<> tuple_cat() { return tuple<>(); } | 
|  |  | 
|  | template <class _Rp, class _Indices, class _Tuple0, class... _Tuples> | 
|  | struct __tuple_cat_return_ref_imp; | 
|  |  | 
|  | template <class... _Types, size_t... _I0, class _Tuple0> | 
|  | struct __tuple_cat_return_ref_imp<tuple<_Types...>, __tuple_indices<_I0...>, _Tuple0> { | 
|  | using _T0 _LIBCPP_NODEBUG = __libcpp_remove_reference_t<_Tuple0>; | 
|  | typedef tuple<_Types..., __copy_cvref_t<_Tuple0, typename tuple_element<_I0, _T0>::type>&&...> type; | 
|  | }; | 
|  |  | 
|  | template <class... _Types, size_t... _I0, class _Tuple0, class _Tuple1, class... _Tuples> | 
|  | struct __tuple_cat_return_ref_imp<tuple<_Types...>, __tuple_indices<_I0...>, _Tuple0, _Tuple1, _Tuples...> | 
|  | : public __tuple_cat_return_ref_imp< | 
|  | tuple<_Types..., | 
|  | __copy_cvref_t<_Tuple0, typename tuple_element<_I0, __libcpp_remove_reference_t<_Tuple0>>::type>&&...>, | 
|  | typename __make_tuple_indices<tuple_size<__libcpp_remove_reference_t<_Tuple1> >::value>::type, | 
|  | _Tuple1, | 
|  | _Tuples...> {}; | 
|  |  | 
|  | template <class _Tuple0, class... _Tuples> | 
|  | struct __tuple_cat_return_ref | 
|  | : public __tuple_cat_return_ref_imp< | 
|  | tuple<>, | 
|  | typename __make_tuple_indices< tuple_size<__libcpp_remove_reference_t<_Tuple0> >::value >::type, | 
|  | _Tuple0, | 
|  | _Tuples...> {}; | 
|  |  | 
|  | template <class _Types, class _I0, class _J0> | 
|  | struct __tuple_cat; | 
|  |  | 
|  | template <class... _Types, size_t... _I0, size_t... _J0> | 
|  | struct __tuple_cat<tuple<_Types...>, __tuple_indices<_I0...>, __tuple_indices<_J0...> > { | 
|  | template <class _Tuple0> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 | 
|  | typename __tuple_cat_return_ref<tuple<_Types...>&&, _Tuple0&&>::type | 
|  | operator()(tuple<_Types...> __t, _Tuple0&& __t0) { | 
|  | (void)__t; // avoid unused parameter warning on GCC when _I0 is empty | 
|  | return std::forward_as_tuple( | 
|  | std::forward<_Types>(std::get<_I0>(__t))..., std::get<_J0>(std::forward<_Tuple0>(__t0))...); | 
|  | } | 
|  |  | 
|  | template <class _Tuple0, class _Tuple1, class... _Tuples> | 
|  | _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 | 
|  | typename __tuple_cat_return_ref<tuple<_Types...>&&, _Tuple0&&, _Tuple1&&, _Tuples&&...>::type | 
|  | operator()(tuple<_Types...> __t, _Tuple0&& __t0, _Tuple1&& __t1, _Tuples&&... __tpls) { | 
|  | (void)__t; // avoid unused parameter warning on GCC when _I0 is empty | 
|  | using _T0 _LIBCPP_NODEBUG = __libcpp_remove_reference_t<_Tuple0>; | 
|  | using _T1 _LIBCPP_NODEBUG = __libcpp_remove_reference_t<_Tuple1>; | 
|  | return __tuple_cat<tuple<_Types..., __copy_cvref_t<_Tuple0, typename tuple_element<_J0, _T0>::type>&&...>, | 
|  | typename __make_tuple_indices<sizeof...(_Types) + tuple_size<_T0>::value>::type, | 
|  | typename __make_tuple_indices<tuple_size<_T1>::value>::type>()( | 
|  | std::forward_as_tuple( | 
|  | std::forward<_Types>(std::get<_I0>(__t))..., std::get<_J0>(std::forward<_Tuple0>(__t0))...), | 
|  | std::forward<_Tuple1>(__t1), | 
|  | std::forward<_Tuples>(__tpls)...); | 
|  | } | 
|  | }; | 
|  |  | 
|  | template <class _TupleDst, class _TupleSrc, size_t... _Indices> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _TupleDst | 
|  | __tuple_cat_select_element_wise(_TupleSrc&& __src, __tuple_indices<_Indices...>) { | 
|  | static_assert(tuple_size<_TupleDst>::value == tuple_size<_TupleSrc>::value, | 
|  | "misuse of __tuple_cat_select_element_wise with tuples of different sizes"); | 
|  | return _TupleDst(std::get<_Indices>(std::forward<_TupleSrc>(__src))...); | 
|  | } | 
|  |  | 
|  | template <class _Tuple0, class... _Tuples> | 
|  | inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename __tuple_cat_return<_Tuple0, _Tuples...>::type | 
|  | tuple_cat(_Tuple0&& __t0, _Tuples&&... __tpls) { | 
|  | using _T0 _LIBCPP_NODEBUG          = __libcpp_remove_reference_t<_Tuple0>; | 
|  | using _TRet _LIBCPP_NODEBUG        = typename __tuple_cat_return<_Tuple0, _Tuples...>::type; | 
|  | using _T0Indices _LIBCPP_NODEBUG   = typename __make_tuple_indices<tuple_size<_T0>::value>::type; | 
|  | using _TRetIndices _LIBCPP_NODEBUG = typename __make_tuple_indices<tuple_size<_TRet>::value>::type; | 
|  | return std::__tuple_cat_select_element_wise<_TRet>( | 
|  | __tuple_cat<tuple<>, __tuple_indices<>, _T0Indices>()( | 
|  | tuple<>(), std::forward<_Tuple0>(__t0), std::forward<_Tuples>(__tpls)...), | 
|  | _TRetIndices()); | 
|  | } | 
|  |  | 
|  | template <class... _Tp, class _Alloc> | 
|  | struct uses_allocator<tuple<_Tp...>, _Alloc> : true_type {}; | 
|  |  | 
|  | #    if _LIBCPP_STD_VER >= 17 | 
|  | #      define _LIBCPP_NOEXCEPT_RETURN(...)                                                                             \ | 
|  | noexcept(noexcept(__VA_ARGS__)) { return __VA_ARGS__; } | 
|  |  | 
|  | // The _LIBCPP_NOEXCEPT_RETURN macro breaks formatting. | 
|  | // clang-format off | 
|  | template <class _Fn, class _Tuple, size_t... _Id> | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) | 
|  | __apply_tuple_impl(_Fn&& __f, _Tuple&& __t, __tuple_indices<_Id...>) | 
|  | _LIBCPP_NOEXCEPT_RETURN(std::__invoke(std::forward<_Fn>(__f), std::get<_Id>(std::forward<_Tuple>(__t))...)) | 
|  |  | 
|  | template <class _Fn, class _Tuple> | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) apply(_Fn&& __f, _Tuple&& __t) | 
|  | _LIBCPP_NOEXCEPT_RETURN(std::__apply_tuple_impl( | 
|  | std::forward<_Fn>(__f), | 
|  | std::forward<_Tuple>(__t), | 
|  | typename __make_tuple_indices<tuple_size_v<remove_reference_t<_Tuple>>>::type{})) | 
|  |  | 
|  | #if _LIBCPP_STD_VER >= 20 | 
|  | template <class _Tp, class _Tuple, size_t... _Idx> | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr _Tp __make_from_tuple_impl(_Tuple&& __t, __tuple_indices<_Idx...>) | 
|  | noexcept(noexcept(_Tp(std::get<_Idx>(std::forward<_Tuple>(__t))...))) | 
|  | requires is_constructible_v<_Tp, decltype(std::get<_Idx>(std::forward<_Tuple>(__t)))...> { | 
|  | return _Tp(std::get<_Idx>(std::forward<_Tuple>(__t))...); | 
|  | } | 
|  | #else | 
|  | template <class _Tp, class _Tuple, size_t... _Idx> | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr _Tp __make_from_tuple_impl(_Tuple&& __t, __tuple_indices<_Idx...>, | 
|  | enable_if_t<is_constructible_v<_Tp, decltype(std::get<_Idx>(std::forward<_Tuple>(__t)))...>> * = nullptr) | 
|  | _LIBCPP_NOEXCEPT_RETURN(_Tp(std::get<_Idx>(std::forward<_Tuple>(__t))...)) | 
|  | #endif // _LIBCPP_STD_VER >= 20 | 
|  |  | 
|  | template <class _Tp, class _Tuple, | 
|  | class _Seq = typename __make_tuple_indices<tuple_size_v<remove_reference_t<_Tuple>>>::type, class = void> | 
|  | inline constexpr bool __can_make_from_tuple = false; | 
|  |  | 
|  | template <class _Tp, class _Tuple, size_t... _Idx> | 
|  | inline constexpr bool __can_make_from_tuple<_Tp, _Tuple, __tuple_indices<_Idx...>, | 
|  | enable_if_t<is_constructible_v<_Tp, decltype(std::get<_Idx>(std::declval<_Tuple>()))...>>> = true; | 
|  |  | 
|  | // Based on LWG3528(https://wg21.link/LWG3528) and http://eel.is/c++draft/description#structure.requirements-9, | 
|  | // the standard allows to impose requirements, we constraint std::make_from_tuple to make std::make_from_tuple | 
|  | // SFINAE friendly and also avoid worse diagnostic messages. We still keep the constraints of std::__make_from_tuple_impl | 
|  | // so that std::__make_from_tuple_impl will have the same advantages when used alone. | 
|  | #if _LIBCPP_STD_VER >= 20 | 
|  | template <class _Tp, class _Tuple> | 
|  | requires __can_make_from_tuple<_Tp, _Tuple> // strengthen | 
|  | #else | 
|  | template <class _Tp, class _Tuple, class = enable_if_t<__can_make_from_tuple<_Tp, _Tuple>>> // strengthen | 
|  | #endif // _LIBCPP_STD_VER >= 20 | 
|  | inline _LIBCPP_HIDE_FROM_ABI constexpr _Tp make_from_tuple(_Tuple&& __t) | 
|  | _LIBCPP_NOEXCEPT_RETURN(std::__make_from_tuple_impl<_Tp>( | 
|  | std::forward<_Tuple>(__t), typename __make_tuple_indices<tuple_size_v<remove_reference_t<_Tuple>>>::type{})) | 
|  | #    undef _LIBCPP_NOEXCEPT_RETURN | 
|  |  | 
|  | #  endif // _LIBCPP_STD_VER >= 17 | 
|  |  | 
|  | #endif // !defined(_LIBCPP_CXX03_LANG) | 
|  |  | 
|  | _LIBCPP_END_NAMESPACE_STD | 
|  |  | 
|  | _LIBCPP_POP_MACROS | 
|  |  | 
|  | // clang-format on | 
|  |  | 
|  | #  if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20 | 
|  | #    include <cstddef> | 
|  | #    include <exception> | 
|  | #    include <iosfwd> | 
|  | #    include <new> | 
|  | #    include <type_traits> | 
|  | #    include <typeinfo> | 
|  | #    include <utility> | 
|  | #  endif | 
|  | #endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS) | 
|  |  | 
|  | #endif // _LIBCPP_TUPLE |