intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 636 insertions, 0 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/include/__tuple b/contrib/libs/cxxsupp/libcxx/include/__tuple
new file mode 100644
index 0000000000..08f4dd5efa
--- /dev/null
+++ b/contrib/libs/cxxsupp/libcxx/include/__tuple
@@ -0,0 +1,636 @@
+// -*- 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
+
+#include <__config>
+#include <cstddef>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> class _LIBCPP_TEMPLATE_VIS tuple_size;
+
+#if !defined(_LIBCPP_CXX03_LANG)
+template <class _Tp, class...>
+using __enable_if_tuple_size_imp = _Tp;
+
+template <class _Tp>
+class _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
+    const _Tp,
+    typename enable_if<!is_volatile<_Tp>::value>::type,
+    integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
+    : public integral_constant<size_t, tuple_size<_Tp>::value> {};
+
+template <class _Tp>
+class _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
+    volatile _Tp,
+    typename enable_if<!is_const<_Tp>::value>::type,
+    integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
+    : public integral_constant<size_t, tuple_size<_Tp>::value> {};
+
+template <class _Tp>
+class _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
+    const volatile _Tp,
+    integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
+    : public integral_constant<size_t, tuple_size<_Tp>::value> {};
+
+#else
+template <class _Tp> class _LIBCPP_TEMPLATE_VIS tuple_size<const _Tp> : public tuple_size<_Tp> {};
+template <class _Tp> class _LIBCPP_TEMPLATE_VIS tuple_size<volatile _Tp> : public tuple_size<_Tp> {};
+template <class _Tp> class _LIBCPP_TEMPLATE_VIS tuple_size<const volatile _Tp> : public tuple_size<_Tp> {};
+#endif
+
+template <size_t _Ip, class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_element;
+
+template <size_t _Ip, class _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const _Tp>
+{
+    typedef _LIBCPP_NODEBUG typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type;
+};
+
+template <size_t _Ip, class _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, volatile _Tp>
+{
+    typedef _LIBCPP_NODEBUG typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type;
+};
+
+template <size_t _Ip, class _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const volatile _Tp>
+{
+    typedef _LIBCPP_NODEBUG typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type;
+};
+
+template <class _Tp> struct __tuple_like : false_type {};
+
+template <class _Tp> struct __tuple_like<const _Tp> : public __tuple_like<_Tp> {};
+template <class _Tp> struct __tuple_like<volatile _Tp> : public __tuple_like<_Tp> {};
+template <class _Tp> struct __tuple_like<const volatile _Tp> : public __tuple_like<_Tp> {};
+
+// tuple specializations
+
+#ifndef _LIBCPP_CXX03_LANG
+
+template <size_t...> struct __tuple_indices {};
+
+template <class _IdxType, _IdxType... _Values>
+struct __integer_sequence {
+  template <size_t _Sp>
+  using __to_tuple_indices = __tuple_indices<(_Values + _Sp)...>;
+};
+
+#if defined(__CUDACC__) || !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
+namespace __detail {
+
+template<typename _Tp, size_t ..._Extra> struct __repeat;
+template<typename _Tp, _Tp ..._Np, size_t ..._Extra> struct __repeat<__integer_sequence<_Tp, _Np...>, _Extra...> {
+  typedef _LIBCPP_NODEBUG __integer_sequence<_Tp,
+                           _Np...,
+                           sizeof...(_Np) + _Np...,
+                           2 * sizeof...(_Np) + _Np...,
+                           3 * sizeof...(_Np) + _Np...,
+                           4 * sizeof...(_Np) + _Np...,
+                           5 * sizeof...(_Np) + _Np...,
+                           6 * sizeof...(_Np) + _Np...,
+                           7 * sizeof...(_Np) + _Np...,
+                           _Extra...> type;
+};
+
+template<size_t _Np> struct __parity;
+template<size_t _Np> struct __make : __parity<_Np % 8>::template __pmake<_Np> {};
+
+template<> struct __make<0> { typedef __integer_sequence<size_t> type; };
+template<> struct __make<1> { typedef __integer_sequence<size_t, 0> type; };
+template<> struct __make<2> { typedef __integer_sequence<size_t, 0, 1> type; };
+template<> struct __make<3> { typedef __integer_sequence<size_t, 0, 1, 2> type; };
+template<> struct __make<4> { typedef __integer_sequence<size_t, 0, 1, 2, 3> type; };
+template<> struct __make<5> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4> type; };
+template<> struct __make<6> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5> type; };
+template<> struct __make<7> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5, 6> type; };
+
+template<> struct __parity<0> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type> {}; };
+template<> struct __parity<1> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 1> {}; };
+template<> struct __parity<2> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 2, _Np - 1> {}; };
+template<> struct __parity<3> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 3, _Np - 2, _Np - 1> {}; };
+template<> struct __parity<4> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
+template<> struct __parity<5> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
+template<> struct __parity<6> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 6, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
+template<> struct __parity<7> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 7, _Np - 6, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
+
+} // namespace detail
+
+#endif // !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
+
+#if __has_builtin(__make_integer_seq) && !defined(__CUDACC__)
+template <size_t _Ep, size_t _Sp>
+using __make_indices_imp =
+    typename __make_integer_seq<__integer_sequence, size_t, _Ep - _Sp>::template
+    __to_tuple_indices<_Sp>;
+#else
+template <size_t _Ep, size_t _Sp>
+using __make_indices_imp =
+    typename __detail::__make<_Ep - _Sp>::type::template __to_tuple_indices<_Sp>;
+
+#endif
+
+template <size_t _Ep, size_t _Sp = 0>
+struct __make_tuple_indices
+{
+    static_assert(_Sp <= _Ep, "__make_tuple_indices input error");
+    typedef __make_indices_imp<_Ep, _Sp> type;
+};
+
+
+template <class ..._Tp> class _LIBCPP_TEMPLATE_VIS tuple;
+
+template <class... _Tp> struct __tuple_like<tuple<_Tp...> > : true_type {};
+
+template <class ..._Tp>
+class _LIBCPP_TEMPLATE_VIS tuple_size<tuple<_Tp...> >
+    : public integral_constant<size_t, sizeof...(_Tp)>
+{
+};
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename tuple_element<_Ip, tuple<_Tp...> >::type&
+get(tuple<_Tp...>&) _NOEXCEPT;
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, tuple<_Tp...> >::type&
+get(const tuple<_Tp...>&) _NOEXCEPT;
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename tuple_element<_Ip, tuple<_Tp...> >::type&&
+get(tuple<_Tp...>&&) _NOEXCEPT;
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
+get(const tuple<_Tp...>&&) _NOEXCEPT;
+
+#endif // !defined(_LIBCPP_CXX03_LANG)
+
+// pair specializations
+
+template <class _T1, class _T2> struct __tuple_like<pair<_T1, _T2> > : true_type {};
+
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename tuple_element<_Ip, pair<_T1, _T2> >::type&
+get(pair<_T1, _T2>&) _NOEXCEPT;
+
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
+get(const pair<_T1, _T2>&) _NOEXCEPT;
+
+#ifndef _LIBCPP_CXX03_LANG
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
+get(pair<_T1, _T2>&&) _NOEXCEPT;
+
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
+get(const pair<_T1, _T2>&&) _NOEXCEPT;
+#endif
+
+// array specializations
+
+template <class _Tp, size_t _Size> struct _LIBCPP_TEMPLATE_VIS array;
+
+template <class _Tp, size_t _Size> struct __tuple_like<array<_Tp, _Size> > : true_type {};
+
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp&
+get(array<_Tp, _Size>&) _NOEXCEPT;
+
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&
+get(const array<_Tp, _Size>&) _NOEXCEPT;
+
+#ifndef _LIBCPP_CXX03_LANG
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp&&
+get(array<_Tp, _Size>&&) _NOEXCEPT;
+
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&&
+get(const array<_Tp, _Size>&&) _NOEXCEPT;
+#endif
+
+#ifndef _LIBCPP_CXX03_LANG
+
+// __tuple_types
+
+template <class ..._Tp> struct __tuple_types {};
+
+#if !__has_builtin(__type_pack_element)
+
+namespace __indexer_detail {
+
+template <size_t _Idx, class _Tp>
+struct __indexed { using type _LIBCPP_NODEBUG = _Tp; };
+
+template <class _Types, class _Indexes> struct __indexer;
+
+template <class ..._Types, size_t ..._Idx>
+struct __indexer<__tuple_types<_Types...>, __tuple_indices<_Idx...>>
+    : __indexed<_Idx, _Types>...
+{};
+
+template <size_t _Idx, class _Tp>
+__indexed<_Idx, _Tp> __at_index(__indexed<_Idx, _Tp> const&);
+
+} // namespace __indexer_detail
+
+#if !defined(__CUDACC__) || !defined(_MSC_VER)
+template <size_t _Idx, class ..._Types>
+using __type_pack_element _LIBCPP_NODEBUG = typename decltype(
+    __indexer_detail::__at_index<_Idx>(
+        __indexer_detail::__indexer<
+            __tuple_types<_Types...>,
+            typename __make_tuple_indices<sizeof...(_Types)>::type
+        >{})
+  )::type;
+
+#else // !defined(__CUDACC__) || !defined(_MSC_VER)
+template <size_t _Idx, class ..._Types>
+struct __y_type_pack_element {
+    using __t1 = typename __make_tuple_indices<sizeof...(_Types)>::type;
+    using __t2 = __indexer_detail::__indexer<__tuple_types<_Types...>, __t1>;
+    using __t3 = decltype(__indexer_detail::__at_index<_Idx>(__t2{}));
+    using __t4 = typename __t3::type;
+};
+
+template <size_t _Idx, class ..._Types>
+using __type_pack_element = typename __y_type_pack_element<_Idx, _Types...>::__t4;
+
+#endif // !defined(__CUDACC__) || !defined(_MSC_VER)
+
+#endif // __has_builtin(__type_pack_element)
+
+template <size_t _Ip, class ..._Types>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, __tuple_types<_Types...>>
+{
+    static_assert(_Ip < sizeof...(_Types), "tuple_element index out of range");
+    typedef _LIBCPP_NODEBUG __type_pack_element<_Ip, _Types...> type;
+};
+
+
+template <class ..._Tp>
+class _LIBCPP_TEMPLATE_VIS tuple_size<__tuple_types<_Tp...> >
+    : public integral_constant<size_t, sizeof...(_Tp)>
+{
+};
+
+template <class... _Tp> struct __tuple_like<__tuple_types<_Tp...> > : true_type {};
+
+template <bool _ApplyLV, bool _ApplyConst, bool _ApplyVolatile>
+struct __apply_cv_mf;
+template <>
+struct __apply_cv_mf<false, false, false> {
+  template <class _Tp> using __apply = _Tp;
+};
+template <>
+struct __apply_cv_mf<false, true, false> {
+  template <class _Tp> using __apply _LIBCPP_NODEBUG = const _Tp;
+};
+template <>
+struct __apply_cv_mf<false, false, true> {
+  template <class _Tp> using __apply _LIBCPP_NODEBUG = volatile _Tp;
+};
+template <>
+struct __apply_cv_mf<false, true, true> {
+  template <class _Tp> using __apply _LIBCPP_NODEBUG = const volatile _Tp;
+};
+template <>
+struct __apply_cv_mf<true, false, false> {
+  template <class _Tp> using __apply _LIBCPP_NODEBUG = _Tp&;
+};
+template <>
+struct __apply_cv_mf<true, true, false> {
+  template <class _Tp> using __apply _LIBCPP_NODEBUG = const _Tp&;
+};
+template <>
+struct __apply_cv_mf<true, false, true> {
+  template <class _Tp> using __apply _LIBCPP_NODEBUG = volatile _Tp&;
+};
+template <>
+struct __apply_cv_mf<true, true, true> {
+  template <class _Tp> using __apply _LIBCPP_NODEBUG = const volatile _Tp&;
+};
+template <class _Tp, class _RawTp = typename remove_reference<_Tp>::type>
+using __apply_cv_t _LIBCPP_NODEBUG = __apply_cv_mf<
+    is_lvalue_reference<_Tp>::value,
+    is_const<_RawTp>::value,
+    is_volatile<_RawTp>::value>;
+
+// __make_tuple_types
+
+// __make_tuple_types<_Tuple<_Types...>, _Ep, _Sp>::type is a
+// __tuple_types<_Types...> using only those _Types in the range [_Sp, _Ep).
+// _Sp defaults to 0 and _Ep defaults to tuple_size<_Tuple>.  If _Tuple is a
+// lvalue_reference type, then __tuple_types<_Types&...> is the result.
+
+#ifdef _LIBCPP_COMPILER_MSVC
+
+template<class _TupleTypes, class _Tp>
+struct __make_tuple_types_append_front;
+
+template<class ..._Types, class _Tp>
+struct __make_tuple_types_append_front<__tuple_types<_Types...>, _Tp> {
+    using type = __tuple_types<_Tp, _Types...>;
+};
+
+template<class _TupleTypes, class _Apply, size_t _Ep, size_t _Sp, class = void>
+struct __make_tuple_types_flat;
+
+template<class _Tuple, class _Apply>
+struct __make_tuple_types_flat<_Tuple, _Apply, 0, 0, void> {
+    using type = __tuple_types<>;
+};
+
+template<template<class...> class _Tuple, class _Tp, class ..._Types, class _Apply, size_t _Ep>
+struct __make_tuple_types_flat<_Tuple<_Tp, _Types...>, _Apply, _Ep, 0, enable_if_t<(_Ep > 0)>> {
+    using type = typename __make_tuple_types_append_front<
+        typename __make_tuple_types_flat<__tuple_types<_Types...>, _Apply, _Ep - 1, 0>::type,
+        typename _Apply::template __apply<_Tp>>::type;
+};
+
+template<template <class...> class _Tuple, class _Tp, class ..._Types, class _Apply, size_t _Ep, size_t _Sp>
+struct __make_tuple_types_flat<_Tuple<_Tp, _Types...>, _Apply, _Ep, _Sp, enable_if_t<(_Ep > 0 && _Sp > 0)>> {
+    using type = typename __make_tuple_types_flat<__tuple_types<_Types...>, _Apply, _Ep - 1, _Sp - 1>::type;
+};
+
+template<class _Tp, size_t _Np, class _Apply, size_t _Ep>
+struct __make_tuple_types_flat<array<_Tp, _Np>, _Apply, _Ep, 0, enable_if_t<(_Ep > 0)>> {
+    using type = typename __make_tuple_types_append_front<
+        typename __make_tuple_types_flat<array<_Tp, _Np>, _Apply, _Ep - 1, 0>::type,
+        typename _Apply::template __apply<_Tp>>::type;
+};
+
+template<class _Tp, size_t _Np, class _Apply, size_t _Ep, size_t _Sp>
+struct __make_tuple_types_flat<array<_Tp, _Np>, _Apply, _Ep, _Sp, enable_if_t<(_Sp > 0)>> {
+    using type = typename __make_tuple_types_flat<array<_Tp, _Np>, _Apply, _Ep - _Sp, 0>::type;
+};
+
+template<class _Tp,
+         size_t _Ep = tuple_size<remove_reference_t<_Tp>>::value,
+         size_t _Sp = 0,
+         bool _SameSize = (_Ep == tuple_size<typename remove_reference<_Tp>::type>::value)>
+struct __make_tuple_types {
+    static_assert(_Sp <= _Ep, "__make_tuple_types input error");
+    using _RawTp = typename remove_cv<typename remove_reference<_Tp>::type>::type;
+    using type = typename __make_tuple_types_flat<_RawTp, __apply_cv_t<_Tp>, _Ep, _Sp>::type;
+};
+
+template <class ..._Types, size_t _Ep>
+struct __make_tuple_types<tuple<_Types...>, _Ep, 0, true> {
+  typedef __tuple_types<_Types...> type;
+};
+
+template <class ..._Types, size_t _Ep>
+struct __make_tuple_types<__tuple_types<_Types...>, _Ep, 0, true> {
+  typedef __tuple_types<_Types...> type;
+};
+
+#else
+
+template <class _TupleTypes, class _TupleIndices>
+struct __make_tuple_types_flat;
+
+template <template <class...> class _Tuple, class ..._Types, size_t ..._Idx>
+struct __make_tuple_types_flat<_Tuple<_Types...>, __tuple_indices<_Idx...>> {
+  // Specialization for pair, tuple, and __tuple_types
+  template <class _Tp, class _ApplyFn = __apply_cv_t<_Tp>>
+  using __apply_quals _LIBCPP_NODEBUG = __tuple_types<
+      typename _ApplyFn::template __apply<__type_pack_element<_Idx, _Types...>>...
+    >;
+};
+
+template <class _Vt, size_t _Np, size_t ..._Idx>
+struct __make_tuple_types_flat<array<_Vt, _Np>, __tuple_indices<_Idx...>> {
+  template <size_t>
+  using __value_type = _Vt;
+  template <class _Tp, class _ApplyFn = __apply_cv_t<_Tp>>
+  using __apply_quals = __tuple_types<
+      typename _ApplyFn::template __apply<__value_type<_Idx>>...
+    >;
+};
+
+template <class _Tp, size_t _Ep = tuple_size<typename remove_reference<_Tp>::type>::value,
+          size_t _Sp = 0,
+          bool _SameSize = (_Ep == tuple_size<typename remove_reference<_Tp>::type>::value)>
+struct __make_tuple_types
+{
+    static_assert(_Sp <= _Ep, "__make_tuple_types input error");
+    using _RawTp = typename remove_cv<typename remove_reference<_Tp>::type>::type;
+    using _Maker = __make_tuple_types_flat<_RawTp, typename __make_tuple_indices<_Ep, _Sp>::type>;
+    using type = typename _Maker::template __apply_quals<_Tp>;
+};
+
+template <class ..._Types, size_t _Ep>
+struct __make_tuple_types<tuple<_Types...>, _Ep, 0, true> {
+  typedef _LIBCPP_NODEBUG __tuple_types<_Types...> type;
+};
+
+template <class ..._Types, size_t _Ep>
+struct __make_tuple_types<__tuple_types<_Types...>, _Ep, 0, true> {
+  typedef _LIBCPP_NODEBUG __tuple_types<_Types...> type;
+};
+
+#endif // _LIBCPP_COMPILER_MSVC
+
+template <bool ..._Preds>
+struct __all_dummy;
+
+template <bool ..._Pred>
+using __all = _IsSame<__all_dummy<_Pred...>, __all_dummy<(_Pred | true)...>>;
+
+struct __tuple_sfinae_base {
+  template <template <class, class...> class _Trait,
+            class ..._LArgs, class ..._RArgs>
+  static auto __do_test(__tuple_types<_LArgs...>, __tuple_types<_RArgs...>)
+    -> __all<_Trait<_LArgs, _RArgs>::value...>;
+  template <template <class...> class>
+  static auto __do_test(...) -> false_type;
+
+  template <class _FromArgs, class _ToArgs>
+  using __constructible = decltype(__do_test<is_constructible>(declval<_ToArgs>(), declval<_FromArgs>()));
+  template <class _FromArgs, class _ToArgs>
+  using __convertible = decltype(__do_test<is_convertible>(declval<_FromArgs>(), declval<_ToArgs>()));
+  template <class _FromArgs, class _ToArgs>
+  using __assignable = decltype(__do_test<is_assignable>(declval<_ToArgs>(), declval<_FromArgs>()));
+};
+
+// __tuple_convertible
+
+template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
+                                bool = __tuple_like<_Up>::value,
+                                class = void>
+struct __tuple_convertible
+    : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_convertible<_Tp, _Up, true, true,
+                           typename enable_if<(tuple_size<typename remove_reference<_Tp>::type>::value == tuple_size<_Up>::value)>::type>
+    : public __tuple_sfinae_base::__convertible<
+      typename __make_tuple_types<_Tp>::type
+    , typename __make_tuple_types<_Up>::type
+    >
+{};
+
+// __tuple_constructible
+
+template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
+                                bool = __tuple_like<_Up>::value,
+                                class = void>
+struct __tuple_constructible
+    : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_constructible<_Tp, _Up, true, true,
+                             typename enable_if<(tuple_size<typename remove_reference<_Tp>::type>::value == tuple_size<_Up>::value)>::type>
+    : public __tuple_sfinae_base::__constructible<
+      typename __make_tuple_types<_Tp>::type
+    , typename __make_tuple_types<_Up>::type
+    >
+{};
+
+// __tuple_assignable
+
+template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
+                                bool = __tuple_like<_Up>::value,
+                                class = void>
+struct __tuple_assignable
+    : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_assignable<_Tp, _Up, true, true,
+                          typename enable_if<(tuple_size<typename remove_reference<_Tp>::type>::value == tuple_size<_Up>::value)>::type>
+    : public __tuple_sfinae_base::__assignable<
+      typename __make_tuple_types<_Tp>::type
+    , typename __make_tuple_types<_Up&>::type
+    >
+{};
+
+
+template <size_t _Ip, class ..._Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, tuple<_Tp...> >
+{
+    typedef _LIBCPP_NODEBUG typename tuple_element<_Ip, __tuple_types<_Tp...> >::type type;
+};
+
+#if _LIBCPP_STD_VER > 11
+template <size_t _Ip, class ..._Tp>
+using tuple_element_t _LIBCPP_NODEBUG = typename tuple_element <_Ip, _Tp...>::type;
+#endif
+
+template <bool _IsTuple, class _SizeTrait, size_t _Expected>
+struct __tuple_like_with_size_imp : false_type {};
+
+template <class _SizeTrait, size_t _Expected>
+struct __tuple_like_with_size_imp<true, _SizeTrait, _Expected>
+    : integral_constant<bool, _SizeTrait::value == _Expected> {};
+
+template <class _Tuple, size_t _ExpectedSize,
+          class _RawTuple = typename __uncvref<_Tuple>::type>
+using __tuple_like_with_size _LIBCPP_NODEBUG = __tuple_like_with_size_imp<
+                                   __tuple_like<_RawTuple>::value,
+                                   tuple_size<_RawTuple>, _ExpectedSize
+                              >;
+
+struct _LIBCPP_TYPE_VIS __check_tuple_constructor_fail {
+
+    static constexpr bool __enable_explicit_default() { return false; }
+    static constexpr bool __enable_implicit_default() { return false; }
+    template <class ...>
+    static constexpr bool __enable_explicit() { return false; }
+    template <class ...>
+    static constexpr bool __enable_implicit() { return false; }
+    template <class ...>
+    static constexpr bool __enable_assign() { return false; }
+};
+#endif // !defined(_LIBCPP_CXX03_LANG)
+
+#if _LIBCPP_STD_VER > 14
+
+template <bool _CanCopy, bool _CanMove>
+struct __sfinae_ctor_base {};
+template <>
+struct __sfinae_ctor_base<false, false> {
+  __sfinae_ctor_base() = default;
+  __sfinae_ctor_base(__sfinae_ctor_base const&) = delete;
+  __sfinae_ctor_base(__sfinae_ctor_base &&) = delete;
+  __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default;
+  __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default;
+};
+template <>
+struct __sfinae_ctor_base<true, false> {
+  __sfinae_ctor_base() = default;
+  __sfinae_ctor_base(__sfinae_ctor_base const&) = default;
+  __sfinae_ctor_base(__sfinae_ctor_base &&) = delete;
+  __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default;
+  __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default;
+};
+template <>
+struct __sfinae_ctor_base<false, true> {
+  __sfinae_ctor_base() = default;
+  __sfinae_ctor_base(__sfinae_ctor_base const&) = delete;
+  __sfinae_ctor_base(__sfinae_ctor_base &&) = default;
+  __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default;
+  __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default;
+};
+
+template <bool _CanCopy, bool _CanMove>
+struct __sfinae_assign_base {};
+template <>
+struct __sfinae_assign_base<false, false> {
+  __sfinae_assign_base() = default;
+  __sfinae_assign_base(__sfinae_assign_base const&) = default;
+  __sfinae_assign_base(__sfinae_assign_base &&) = default;
+  __sfinae_assign_base& operator=(__sfinae_assign_base const&) = delete;
+  __sfinae_assign_base& operator=(__sfinae_assign_base&&) = delete;
+};
+template <>
+struct __sfinae_assign_base<true, false> {
+  __sfinae_assign_base() = default;
+  __sfinae_assign_base(__sfinae_assign_base const&) = default;
+  __sfinae_assign_base(__sfinae_assign_base &&) = default;
+  __sfinae_assign_base& operator=(__sfinae_assign_base const&) = default;
+  __sfinae_assign_base& operator=(__sfinae_assign_base&&) = delete;
+};
+template <>
+struct __sfinae_assign_base<false, true> {
+  __sfinae_assign_base() = default;
+  __sfinae_assign_base(__sfinae_assign_base const&) = default;
+  __sfinae_assign_base(__sfinae_assign_base &&) = default;
+  __sfinae_assign_base& operator=(__sfinae_assign_base const&) = delete;
+  __sfinae_assign_base& operator=(__sfinae_assign_base&&) = default;
+};
+#endif // _LIBCPP_STD_VER > 14
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TUPLE