type_traits

// type_traits standard header (core)

// Copyright (c) Microsoft Corporation.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#ifndef _TYPE_TRAITS_
#define _TYPE_TRAITS_
#include <yvals_core.h>
#if _STL_COMPILER_PREPROCESSOR
#include <cstddef>
#include <cstdint>
#include <xtr1common>

#pragma pack(push, _CRT_PACKING)
#pragma warning(push, _STL_WARNING_LEVEL)
#pragma warning(disable : _STL_DISABLED_WARNINGS)
_STL_DISABLE_CLANG_WARNINGS
#pragma push_macro("new")
#undef new

// TRANSITION, non-_Ugly attribute tokens
#pragma push_macro("msvc")
#pragma push_macro("intrinsic")
#pragma push_macro("known_semantics")
#undef msvc
#undef intrinsic
#undef known_semantics

_STD_BEGIN
template <class>
// TRANSITION, CWG-2518: false value attached to a dependent name (for static_assert)
constexpr bool _Always_false = false;

template <bool _First_value, class _First, class... _Rest>
struct _Conjunction { // handle false trait or last trait
    using type = _First;
};

template <class _True, class _Next, class... _Rest>
struct _Conjunction<true, _True, _Next, _Rest...> { // the first trait is true, try the next one
    using type = typename _Conjunction<_Next::value, _Next, _Rest...>::type;
};

_EXPORT_STD template <class... _Traits>
struct conjunction : true_type {}; // If _Traits is empty, true_type

template <class _First, class... _Rest>
struct conjunction<_First, _Rest...> : _Conjunction<_First::value, _First, _Rest...>::type {
    // the first false trait in _Traits, or the last trait if none are false
};

_EXPORT_STD template <class... _Traits>
constexpr bool conjunction_v = conjunction<_Traits...>::value;

_EXPORT_STD template <class _Trait>
struct negation : bool_constant<!static_cast<bool>(_Trait::value)> {}; // The negated result of _Trait

_EXPORT_STD template <class _Trait>
constexpr bool negation_v = negation<_Trait>::value;

_EXPORT_STD template <class _Ty>
constexpr bool is_void_v = is_same_v<remove_cv_t<_Ty>, void>;

_EXPORT_STD template <class _Ty>
struct is_void : bool_constant<is_void_v<_Ty>> {};

_EXPORT_STD template <class... _Types>
using void_t = void;

template <class _Ty>
struct _Identity {
    using type = _Ty;
};
template <class _Ty>
using _Identity_t _MSVC_KNOWN_SEMANTICS = typename _Identity<_Ty>::type;

// Type modifiers
_EXPORT_STD template <class _Ty>
struct add_const { // add top-level const qualifier
    using type = const _Ty;
};

_EXPORT_STD template <class _Ty>
using add_const_t = typename add_const<_Ty>::type;

_EXPORT_STD template <class _Ty>
struct add_volatile { // add top-level volatile qualifier
    using type = volatile _Ty;
};

_EXPORT_STD template <class _Ty>
using add_volatile_t = typename add_volatile<_Ty>::type;

_EXPORT_STD template <class _Ty>
struct add_cv { // add top-level const and volatile qualifiers
    using type = const volatile _Ty;
};

_EXPORT_STD template <class _Ty>
using add_cv_t = typename add_cv<_Ty>::type;

template <class _Ty, class = void>
struct _Add_reference { // add reference (non-referenceable type)
    using _Lvalue = _Ty;
    using _Rvalue = _Ty;
};

template <class _Ty>
struct _Add_reference<_Ty, void_t<_Ty&>> { // (referenceable type)
    using _Lvalue = _Ty&;
    using _Rvalue = _Ty&&;
};

_EXPORT_STD template <class _Ty>
struct add_lvalue_reference {
    using type = typename _Add_reference<_Ty>::_Lvalue;
};

_EXPORT_STD template <class _Ty>
using add_lvalue_reference_t = typename _Add_reference<_Ty>::_Lvalue;

_EXPORT_STD template <class _Ty>
struct add_rvalue_reference {
    using type = typename _Add_reference<_Ty>::_Rvalue;
};

_EXPORT_STD template <class _Ty>
using add_rvalue_reference_t = typename _Add_reference<_Ty>::_Rvalue;

_EXPORT_STD template <class _Ty>
add_rvalue_reference_t<_Ty> declval() noexcept {
    static_assert(_Always_false<_Ty>, "Calling declval is ill-formed, see N4950 [declval]/2.");
}

_EXPORT_STD template <class _Ty>
struct remove_extent { // remove array extent
    using type = _Ty;
};

template <class _Ty, size_t _Ix>
struct remove_extent<_Ty[_Ix]> {
    using type = _Ty;
};

template <class _Ty>
struct remove_extent<_Ty[]> {
    using type = _Ty;
};

_EXPORT_STD template <class _Ty>
using remove_extent_t = typename remove_extent<_Ty>::type;

_EXPORT_STD template <class _Ty>
struct remove_all_extents { // remove all array extents
    using type = _Ty;
};

template <class _Ty, size_t _Ix>
struct remove_all_extents<_Ty[_Ix]> {
    using type = typename remove_all_extents<_Ty>::type;
};

template <class _Ty>
struct remove_all_extents<_Ty[]> {
    using type = typename remove_all_extents<_Ty>::type;
};

_EXPORT_STD template <class _Ty>
using remove_all_extents_t = typename remove_all_extents<_Ty>::type;

_EXPORT_STD template <class _Ty>
struct remove_pointer {
    using type = _Ty;
};

template <class _Ty>
struct remove_pointer<_Ty*> {
    using type = _Ty;
};

template <class _Ty>
struct remove_pointer<_Ty* const> {
    using type = _Ty;
};

template <class _Ty>
struct remove_pointer<_Ty* volatile> {
    using type = _Ty;
};

template <class _Ty>
struct remove_pointer<_Ty* const volatile> {
    using type = _Ty;
};

_EXPORT_STD template <class _Ty>
using remove_pointer_t = typename remove_pointer<_Ty>::type;

template <class _Ty, class = void>
struct _Add_pointer { // add pointer (pointer type cannot be formed)
    using type = _Ty;
};

template <class _Ty>
struct _Add_pointer<_Ty, void_t<remove_reference_t<_Ty>*>> { // (pointer type can be formed)
    using type = remove_reference_t<_Ty>*;
};

_EXPORT_STD template <class _Ty>
struct add_pointer {
    using type = typename _Add_pointer<_Ty>::type;
};

_EXPORT_STD template <class _Ty>
using add_pointer_t = typename _Add_pointer<_Ty>::type;

_EXPORT_STD template <class>
constexpr bool is_array_v = false; // determine whether type argument is an array

template <class _Ty, size_t _Nx>
constexpr bool is_array_v<_Ty[_Nx]> = true;

template <class _Ty>
constexpr bool is_array_v<_Ty[]> = true;

_EXPORT_STD template <class _Ty>
struct is_array : bool_constant<is_array_v<_Ty>> {};

#if _HAS_CXX20
_EXPORT_STD template <class>
constexpr bool is_bounded_array_v = false;

template <class _Ty, size_t _Nx>
constexpr bool is_bounded_array_v<_Ty[_Nx]> = true;

_EXPORT_STD template <class _Ty>
struct is_bounded_array : bool_constant<is_bounded_array_v<_Ty>> {};

_EXPORT_STD template <class>
constexpr bool is_unbounded_array_v = false;

template <class _Ty>
constexpr bool is_unbounded_array_v<_Ty[]> = true;

_EXPORT_STD template <class _Ty>
struct is_unbounded_array : bool_constant<is_unbounded_array_v<_Ty>> {};
#endif // _HAS_CXX20

_EXPORT_STD template <class>
constexpr bool is_lvalue_reference_v = false; // determine whether type argument is an lvalue reference

template <class _Ty>
constexpr bool is_lvalue_reference_v<_Ty&> = true;

_EXPORT_STD template <class _Ty>
struct is_lvalue_reference : bool_constant<is_lvalue_reference_v<_Ty>> {};

_EXPORT_STD template <class>
constexpr bool is_rvalue_reference_v = false; // determine whether type argument is an rvalue reference

template <class _Ty>
constexpr bool is_rvalue_reference_v<_Ty&&> = true;

_EXPORT_STD template <class _Ty>
struct is_rvalue_reference : bool_constant<is_rvalue_reference_v<_Ty>> {};

_EXPORT_STD template <class>
constexpr bool is_reference_v = false; // determine whether type argument is a reference

template <class _Ty>
constexpr bool is_reference_v<_Ty&> = true;

template <class _Ty>
constexpr bool is_reference_v<_Ty&&> = true;

_EXPORT_STD template <class _Ty>
struct is_reference : bool_constant<is_reference_v<_Ty>> {};

_EXPORT_STD template <class>
constexpr bool is_pointer_v = false; // determine whether _Ty is a pointer

template <class _Ty>
constexpr bool is_pointer_v<_Ty*> = true;

template <class _Ty>
constexpr bool is_pointer_v<_Ty* const> = true;

template <class _Ty>
constexpr bool is_pointer_v<_Ty* volatile> = true;

template <class _Ty>
constexpr bool is_pointer_v<_Ty* const volatile> = true;

_EXPORT_STD template <class _Ty>
struct is_pointer : bool_constant<is_pointer_v<_Ty>> {};

_EXPORT_STD template <class _Ty>
constexpr bool is_null_pointer_v =
    is_same_v<remove_cv_t<_Ty>, nullptr_t>; // determine whether _Ty is cv-qualified nullptr_t

_EXPORT_STD template <class _Ty>
struct is_null_pointer : bool_constant<is_null_pointer_v<_Ty>> {};

_EXPORT_STD template <class _Ty>
struct is_union : bool_constant<__is_union(_Ty)> {}; // determine whether _Ty is a union

_EXPORT_STD template <class _Ty>
constexpr bool is_union_v = __is_union(_Ty);

_EXPORT_STD template <class _Ty>
struct is_class : bool_constant<__is_class(_Ty)> {}; // determine whether _Ty is a class

_EXPORT_STD template <class _Ty>
constexpr bool is_class_v = __is_class(_Ty);

_EXPORT_STD template <class _Ty>
constexpr bool is_fundamental_v = is_arithmetic_v<_Ty> || is_void_v<_Ty> || is_null_pointer_v<_Ty>;

_EXPORT_STD template <class _Ty>
struct is_fundamental : bool_constant<is_fundamental_v<_Ty>> {}; // determine whether _Ty is a fundamental type

_EXPORT_STD template <class _From, class _To>
struct is_convertible : bool_constant<__is_convertible_to(_From, _To)> {
    // determine whether _From is convertible to _To
};

_EXPORT_STD template <class _From, class _To>
constexpr bool is_convertible_v = __is_convertible_to(_From, _To);

#if !defined(__clang__) && !defined(__EDG__) // TRANSITION, DevCom-1627396
template <class _Ty>
struct is_convertible<_Ty&, volatile _Ty&> : true_type {};

template <class _Ty>
struct is_convertible<volatile _Ty&, volatile _Ty&> : true_type {};

template <class _Ty>
struct is_convertible<_Ty&, const volatile _Ty&> : true_type {};

template <class _Ty>
struct is_convertible<volatile _Ty&, const volatile _Ty&> : true_type {};

template <class _Ty>
constexpr bool is_convertible_v<_Ty&, volatile _Ty&> = true;

template <class _Ty>
constexpr bool is_convertible_v<volatile _Ty&, volatile _Ty&> = true;

template <class _Ty>
constexpr bool is_convertible_v<_Ty&, const volatile _Ty&> = true;

template <class _Ty>
constexpr bool is_convertible_v<volatile _Ty&, const volatile _Ty&> = true;
#endif // ^^^ workaround ^^^

_EXPORT_STD template <class _Ty>
struct is_enum : bool_constant<__is_enum(_Ty)> {}; // determine whether _Ty is an enumerated type

_EXPORT_STD template <class _Ty>
constexpr bool is_enum_v = __is_enum(_Ty);

#if _HAS_CXX23
_EXPORT_STD template <class _Ty>
constexpr bool is_scoped_enum_v = conjunction_v<is_enum<_Ty>, negation<is_convertible<_Ty, int>>>;

_EXPORT_STD template <class _Ty>
struct is_scoped_enum : bool_constant<is_scoped_enum_v<_Ty>> {};
#endif // _HAS_CXX23

_EXPORT_STD template <class _Ty>
struct is_compound : bool_constant<!is_fundamental_v<_Ty>> {}; // determine whether _Ty is a compound type

_EXPORT_STD template <class _Ty>
constexpr bool is_compound_v = !is_fundamental_v<_Ty>;

#define _EMIT_CDECL(FUNC, OPT1, OPT2, OPT3) FUNC(__cdecl, OPT1, OPT2, OPT3)

#ifdef _M_CEE
#define _EMIT_CLRCALL(FUNC, OPT1, OPT2, OPT3) FUNC(__clrcall, OPT1, OPT2, OPT3)
#else // ^^^ __clrcall supported / __clrcall not supported vvv
#define _EMIT_CLRCALL(FUNC, OPT1, OPT2, OPT3)
#endif // ^^^ __clrcall not supported ^^^

#if defined(_M_IX86) && !defined(_M_CEE)
#define _EMIT_FASTCALL(FUNC, OPT1, OPT2, OPT3) FUNC(__fastcall, OPT1, OPT2, OPT3)
#else // ^^^ __fastcall supported / __fastcall not supported vvv
#define _EMIT_FASTCALL(FUNC, OPT1, OPT2, OPT3)
#endif // ^^^ __fastcall not supported ^^^

#ifdef _M_IX86
#define _EMIT_STDCALL(FUNC, OPT1, OPT2, OPT3)  FUNC(__stdcall, OPT1, OPT2, OPT3)
#define _EMIT_THISCALL(FUNC, OPT1, OPT2, OPT3) FUNC(__thiscall, OPT1, OPT2, OPT3)
#else // ^^^ __stdcall and __thiscall supported / __stdcall and __thiscall not supported vvv
#define _EMIT_STDCALL(FUNC, OPT1, OPT2, OPT3)
#define _EMIT_THISCALL(FUNC, OPT1, OPT2, OPT3)
#endif // ^^^ __stdcall and __thiscall not supported ^^^

#if ((defined(_M_IX86) && _M_IX86_FP >= 2) || defined(_M_X64)) && !defined(_M_CEE)
#define _EMIT_VECTORCALL(FUNC, OPT1, OPT2, OPT3) FUNC(__vectorcall, OPT1, OPT2, OPT3)
#else // ^^^ __vectorcall supported / __vectorcall not supported vvv
#define _EMIT_VECTORCALL(FUNC, OPT1, OPT2, OPT3)
#endif // ^^^ __vectorcall not supported ^^^

#define _NON_MEMBER_CALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT) \
    _EMIT_CDECL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)          \
    _EMIT_CLRCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)        \
    _EMIT_FASTCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)       \
    _EMIT_STDCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)        \
    _EMIT_VECTORCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)

#define _NON_MEMBER_CALL_CV(FUNC, REF_OPT, NOEXCEPT_OPT)    \
    _NON_MEMBER_CALL(FUNC, , REF_OPT, NOEXCEPT_OPT)         \
    _NON_MEMBER_CALL(FUNC, const, REF_OPT, NOEXCEPT_OPT)    \
    _NON_MEMBER_CALL(FUNC, volatile, REF_OPT, NOEXCEPT_OPT) \
    _NON_MEMBER_CALL(FUNC, const volatile, REF_OPT, NOEXCEPT_OPT)

#define _NON_MEMBER_CALL_CV_REF(FUNC, NOEXCEPT_OPT) \
    _NON_MEMBER_CALL_CV(FUNC, , NOEXCEPT_OPT)       \
    _NON_MEMBER_CALL_CV(FUNC, &, NOEXCEPT_OPT)      \
    _NON_MEMBER_CALL_CV(FUNC, &&, NOEXCEPT_OPT)

#ifdef __cpp_noexcept_function_type
#define _NON_MEMBER_CALL_CV_REF_NOEXCEPT(FUNC) \
    _NON_MEMBER_CALL_CV_REF(FUNC, )            \
    _NON_MEMBER_CALL_CV_REF(FUNC, noexcept)
#else // ^^^ defined(__cpp_noexcept_function_type) / !defined(__cpp_noexcept_function_type) vvv
#define _NON_MEMBER_CALL_CV_REF_NOEXCEPT(FUNC) _NON_MEMBER_CALL_CV_REF(FUNC, )
#endif // ^^^ !defined(__cpp_noexcept_function_type) ^^^

#define _MEMBER_CALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT) \
    _EMIT_CDECL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)      \
    _EMIT_CLRCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)    \
    _EMIT_FASTCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)   \
    _EMIT_STDCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)    \
    _EMIT_THISCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)   \
    _EMIT_VECTORCALL(FUNC, CV_OPT, REF_OPT, NOEXCEPT_OPT)

#define _MEMBER_CALL_CV(FUNC, REF_OPT, NOEXCEPT_OPT)    \
    _MEMBER_CALL(FUNC, , REF_OPT, NOEXCEPT_OPT)         \
    _MEMBER_CALL(FUNC, const, REF_OPT, NOEXCEPT_OPT)    \
    _MEMBER_CALL(FUNC, volatile, REF_OPT, NOEXCEPT_OPT) \
    _MEMBER_CALL(FUNC, const volatile, REF_OPT, NOEXCEPT_OPT)

#define _MEMBER_CALL_CV_REF(FUNC, NOEXCEPT_OPT) \
    _MEMBER_CALL_CV(FUNC, , NOEXCEPT_OPT)       \
    _MEMBER_CALL_CV(FUNC, &, NOEXCEPT_OPT)      \
    _MEMBER_CALL_CV(FUNC, &&, NOEXCEPT_OPT)

#ifdef __cpp_noexcept_function_type
#define _MEMBER_CALL_CV_REF_NOEXCEPT(FUNC) \
    _MEMBER_CALL_CV_REF(FUNC, )            \
    _MEMBER_CALL_CV_REF(FUNC, noexcept)
#else // ^^^ defined(__cpp_noexcept_function_type) / !defined(__cpp_noexcept_function_type) vvv
#define _MEMBER_CALL_CV_REF_NOEXCEPT(FUNC) _MEMBER_CALL_CV_REF(FUNC, )
#endif // ^^^ !defined(__cpp_noexcept_function_type) ^^^

#ifdef __cpp_noexcept_function_type
#define _CLASS_DEFINE_CV_REF_NOEXCEPT(CLASS) \
    CLASS(_EMPTY_ARGUMENT)                   \
    CLASS(const)                             \
    CLASS(volatile)                          \
    CLASS(const volatile)                    \
    CLASS(&)                                 \
    CLASS(const&)                            \
    CLASS(volatile&)                         \
    CLASS(const volatile&)                   \
    CLASS(&&)                                \
    CLASS(const&&)                           \
    CLASS(volatile&&)                        \
    CLASS(const volatile&&)                  \
    CLASS(noexcept)                          \
    CLASS(const noexcept)                    \
    CLASS(volatile noexcept)                 \
    CLASS(const volatile noexcept)           \
    CLASS(& noexcept)                        \
    CLASS(const& noexcept)                   \
    CLASS(volatile& noexcept)                \
    CLASS(const volatile& noexcept)          \
    CLASS(&& noexcept)                       \
    CLASS(const&& noexcept)                  \
    CLASS(volatile&& noexcept)               \
    CLASS(const volatile&& noexcept)
#else // ^^^ defined(__cpp_noexcept_function_type) / !defined(__cpp_noexcept_function_type) vvv
#define _CLASS_DEFINE_CV_REF_NOEXCEPT(CLASS) \
    CLASS(_EMPTY_ARGUMENT)                   \
    CLASS(const)                             \
    CLASS(volatile)                          \
    CLASS(const volatile)                    \
    CLASS(&)                                 \
    CLASS(const&)                            \
    CLASS(volatile&)                         \
    CLASS(const volatile&)                   \
    CLASS(&&)                                \
    CLASS(const&&)                           \
    CLASS(volatile&&)                        \
    CLASS(const volatile&&)
#endif // ^^^ !defined(__cpp_noexcept_function_type) ^^^

template <class... _Types>
struct _Arg_types {}; // provide argument_type, etc. when sizeof...(_Types) is 1 or 2

template <class _Ty1>
struct _Arg_types<_Ty1> {
    using _ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = _Ty1;
};

template <class _Ty1, class _Ty2>
struct _Arg_types<_Ty1, _Ty2> {
    using _FIRST_ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS  = _Ty1;
    using _SECOND_ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = _Ty2;
};

template <class _Ty>
struct _Is_memfunptr { // base class for member function pointer predicates
    using _Bool_type = false_type; // NB: members are user-visible via _Weak_types
};

#define _IS_MEMFUNPTR(CALL_OPT, CV_OPT, REF_OPT, NOEXCEPT_OPT)                            \
    template <class _Ret, class _Arg0, class... _Types>                                   \
    struct _Is_memfunptr<_Ret (CALL_OPT _Arg0::*)(_Types...) CV_OPT REF_OPT NOEXCEPT_OPT> \
        : _Arg_types<CV_OPT _Arg0*, _Types...> {                                          \
        using _Bool_type                                          = true_type;            \
        using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = _Ret;                 \
        using _Class_type                                         = _Arg0;                \
        using _Guide_type = enable_if<!is_same_v<int REF_OPT, int&&>, _Ret(_Types...)>;   \
    };

_MEMBER_CALL_CV_REF_NOEXCEPT(_IS_MEMFUNPTR)
#undef _IS_MEMFUNPTR

#define _IS_MEMFUNPTR_ELLIPSIS(CV_REF_NOEXCEPT_OPT)                                   \
    template <class _Ret, class _Arg0, class... _Types>                               \
    struct _Is_memfunptr<_Ret (_Arg0::*)(_Types..., ...)                              \
            CV_REF_NOEXCEPT_OPT> { /* no calling conventions for ellipsis */          \
        using _Bool_type                                          = true_type;        \
        using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = _Ret;             \
        using _Class_type                                         = _Arg0;            \
        using _Guide_type                                         = enable_if<false>; \
    };

_CLASS_DEFINE_CV_REF_NOEXCEPT(_IS_MEMFUNPTR_ELLIPSIS)
#undef _IS_MEMFUNPTR_ELLIPSIS

#if _HAS_CXX23 && !defined(__clang__) // TRANSITION, DevCom-10107077, Clang has not implemented Deducing this
#define _IS_MEMFUNPTR_EXPLICIT_THIS_GUIDES(CALL_OPT, CV_OPT, REF_OPT, NOEXCEPT_OPT) \
    template <class _Ret, class _Self, class... _Args>                              \
    struct _Is_memfunptr<_Ret(CALL_OPT*)(_Self, _Args...) NOEXCEPT_OPT> {           \
        using _Bool_type  = false_type;                                             \
        using _Guide_type = _Identity<_Ret(_Args...)>;                              \
    };

_NON_MEMBER_CALL(_IS_MEMFUNPTR_EXPLICIT_THIS_GUIDES, , , )
#ifdef __cpp_noexcept_function_type
_NON_MEMBER_CALL(_IS_MEMFUNPTR_EXPLICIT_THIS_GUIDES, , , noexcept)
#endif // defined(__cpp_noexcept_function_type)

#undef _IS_MEMFUNPTR_EXPLICIT_THIS_GUIDES
#endif // _HAS_CXX23 && !defined(__clang__)

#ifdef __clang__
_EXPORT_STD template <class _Ty>
constexpr bool is_member_function_pointer_v = __is_member_function_pointer(_Ty);
#else // ^^^ Clang / Other vvv
_EXPORT_STD template <class _Ty>
constexpr bool is_member_function_pointer_v = _Is_memfunptr<remove_cv_t<_Ty>>::_Bool_type::value;
#endif // ^^^ Other ^^^

_EXPORT_STD template <class _Ty>
struct is_member_function_pointer : bool_constant<is_member_function_pointer_v<_Ty>> {};

_EXPORT_STD template <class>
constexpr bool is_const_v = false; // determine whether type argument is const qualified

template <class _Ty>
constexpr bool is_const_v<const _Ty> = true;

_EXPORT_STD template <class _Ty>
struct is_const : bool_constant<is_const_v<_Ty>> {};

_EXPORT_STD template <class>
constexpr bool is_volatile_v = false; // determine whether type argument is volatile qualified

template <class _Ty>
constexpr bool is_volatile_v<volatile _Ty> = true;

_EXPORT_STD template <class _Ty>
struct is_volatile : bool_constant<is_volatile_v<_Ty>> {};

_EXPORT_STD template <class _Ty>
constexpr bool is_function_v = // only function types and reference types can't be const qualified
    !is_const_v<const _Ty> && !is_reference_v<_Ty>;

_EXPORT_STD template <class _Ty>
struct is_function : bool_constant<is_function_v<_Ty>> {};

_EXPORT_STD template <class _Ty>
constexpr bool is_object_v = // only function types and reference types can't be const qualified
    is_const_v<const _Ty> && !is_void_v<_Ty>;

_EXPORT_STD template <class _Ty>
struct is_object : bool_constant<is_object_v<_Ty>> {};

template <class>
struct _Is_member_object_pointer {
    static constexpr bool value = false;
};

template <class _Ty1, class _Ty2>
struct _Is_member_object_pointer<_Ty1 _Ty2::*> {
    static constexpr bool value = !is_function_v<_Ty1>;
    using _Class_type           = _Ty2;
};

#ifdef __clang__
_EXPORT_STD template <class _Ty>
constexpr bool is_member_object_pointer_v = __is_member_object_pointer(_Ty);
#else // ^^^ Clang / Other vvv
_EXPORT_STD template <class _Ty>
constexpr bool is_member_object_pointer_v = _Is_member_object_pointer<remove_cv_t<_Ty>>::value;
#endif // ^^^ Other ^^^

_EXPORT_STD template <class _Ty>
struct is_member_object_pointer : bool_constant<is_member_object_pointer_v<_Ty>> {};

#ifdef __clang__
_EXPORT_STD template <class _Ty>
constexpr bool is_member_pointer_v = __is_member_pointer(_Ty);
#else // ^^^ Clang / Other vvv
_EXPORT_STD template <class _Ty>
constexpr bool is_member_pointer_v = is_member_object_pointer_v<_Ty> || is_member_function_pointer_v<_Ty>;
#endif // ^^^ Other ^^^

_EXPORT_STD template <class _Ty>
struct is_member_pointer : bool_constant<is_member_pointer_v<_Ty>> {}; // determine whether _Ty is a pointer to member

_EXPORT_STD template <class _Ty>
constexpr bool is_scalar_v = // determine whether _Ty is a scalar type
    is_arithmetic_v<_Ty> || is_enum_v<_Ty> || is_pointer_v<_Ty> || is_member_pointer_v<_Ty> || is_null_pointer_v<_Ty>;

_EXPORT_STD template <class _Ty>
struct is_scalar : bool_constant<is_scalar_v<_Ty>> {};

_EXPORT_STD template <class _Ty>
struct _CXX20_DEPRECATE_IS_POD is_pod : bool_constant<__is_pod(_Ty)> {}; // determine whether _Ty is a POD type

_EXPORT_STD template <class _Ty>
_CXX20_DEPRECATE_IS_POD constexpr bool is_pod_v = __is_pod(_Ty);

_EXPORT_STD template <class _Ty>
struct is_empty : bool_constant<__is_empty(_Ty)> {}; // determine whether _Ty is an empty class

_EXPORT_STD template <class _Ty>
constexpr bool is_empty_v = __is_empty(_Ty);

_EXPORT_STD template <class _Ty>
struct is_polymorphic : bool_constant<__is_polymorphic(_Ty)> {}; // determine whether _Ty is a polymorphic type

_EXPORT_STD template <class _Ty>
constexpr bool is_polymorphic_v = __is_polymorphic(_Ty);

_EXPORT_STD template <class _Ty>
struct is_abstract : bool_constant<__is_abstract(_Ty)> {}; // determine whether _Ty is an abstract class

_EXPORT_STD template <class _Ty>
constexpr bool is_abstract_v = __is_abstract(_Ty);

_EXPORT_STD template <class _Ty>
struct is_final : bool_constant<__is_final(_Ty)> {}; // determine whether _Ty is a final class

_EXPORT_STD template <class _Ty>
constexpr bool is_final_v = __is_final(_Ty);

_EXPORT_STD template <class _Ty>
struct is_standard_layout : bool_constant<__is_standard_layout(_Ty)> {}; // determine whether _Ty is standard layout

_EXPORT_STD template <class _Ty>
constexpr bool is_standard_layout_v = __is_standard_layout(_Ty);

#if _HAS_DEPRECATED_IS_LITERAL_TYPE
_EXPORT_STD template <class _Ty>
struct _CXX17_DEPRECATE_IS_LITERAL_TYPE is_literal_type : bool_constant<__is_literal_type(_Ty)> {
    // determine whether _Ty is a literal type
};

_EXPORT_STD template <class _Ty>
_CXX17_DEPRECATE_IS_LITERAL_TYPE constexpr bool is_literal_type_v = __is_literal_type(_Ty);
#endif // _HAS_DEPRECATED_IS_LITERAL_TYPE

_EXPORT_STD template <class _Ty>
struct is_trivial : bool_constant<__is_trivial(_Ty)> {}; // determine whether _Ty is a trivial type

_EXPORT_STD template <class _Ty>
constexpr bool is_trivial_v = __is_trivial(_Ty);

_EXPORT_STD template <class _Ty>
struct is_trivially_copyable : bool_constant<__is_trivially_copyable(_Ty)> {
    // determine whether _Ty is a trivially copyable type
};

_EXPORT_STD template <class _Ty>
constexpr bool is_trivially_copyable_v = __is_trivially_copyable(_Ty);

_EXPORT_STD template <class _Ty>
struct has_virtual_destructor : bool_constant<__has_virtual_destructor(_Ty)> {
    // determine whether _Ty has a virtual destructor
};

_EXPORT_STD template <class _Ty>
constexpr bool has_virtual_destructor_v = __has_virtual_destructor(_Ty);

#if _HAS_CXX17
_EXPORT_STD template <class _Ty>
struct has_unique_object_representations : bool_constant<__has_unique_object_representations(_Ty)> {
    // determine whether _Ty has unique object representations
};

_EXPORT_STD template <class _Ty>
constexpr bool has_unique_object_representations_v = __has_unique_object_representations(_Ty);

#ifdef __EDG__ // TRANSITION, VSO-1690654
template <class _Ty>
struct _Is_aggregate_impl : bool_constant<__is_aggregate(_Ty)> {};

_EXPORT_STD template <class _Ty>
constexpr bool is_aggregate_v = disjunction_v<is_array<_Ty>, _Is_aggregate_impl<_Ty>>;

_EXPORT_STD template <class _Ty>
struct is_aggregate : bool_constant<is_aggregate_v<_Ty>> {};
#else // ^^^ workaround / no workaround vvv
_EXPORT_STD template <class _Ty>
struct is_aggregate : bool_constant<__is_aggregate(_Ty)> {};

_EXPORT_STD template <class _Ty>
constexpr bool is_aggregate_v = __is_aggregate(_Ty);
#endif // ^^^ no workaround ^^^
#endif // _HAS_CXX17

_EXPORT_STD template <class _Ty, class... _Args>
struct is_constructible : bool_constant<__is_constructible(_Ty, _Args...)> {
    // determine whether _Ty can be direct-initialized with _Args...
};

_EXPORT_STD template <class _Ty, class... _Args>
constexpr bool is_constructible_v = __is_constructible(_Ty, _Args...);

_EXPORT_STD template <class _Ty>
struct is_copy_constructible : bool_constant<__is_constructible(_Ty, add_lvalue_reference_t<const _Ty>)> {
    // determine whether _Ty can be direct-initialized with an lvalue const _Ty
};

_EXPORT_STD template <class _Ty>
constexpr bool is_copy_constructible_v = __is_constructible(_Ty, add_lvalue_reference_t<const _Ty>);

_EXPORT_STD template <class _Ty>
struct is_default_constructible : bool_constant<__is_constructible(_Ty)> {
    // determine whether _Ty can be value-initialized
};

_EXPORT_STD template <class _Ty>
constexpr bool is_default_constructible_v = __is_constructible(_Ty);

template <class _Ty, class = void>
struct _Is_implicitly_default_constructible : false_type {
    // determine whether _Ty can be copy-initialized with {}
};

template <class _Ty>
void _Implicitly_default_construct(const _Ty&);

template <class _Ty>
struct _Is_implicitly_default_constructible<_Ty, void_t<decltype(_Implicitly_default_construct<_Ty>({}))>> : true_type {
};

_EXPORT_STD template <class _Ty>
struct is_move_constructible : bool_constant<__is_constructible(_Ty, _Ty)> {
    // determine whether _Ty can be direct-initialized from an rvalue _Ty
};

_EXPORT_STD template <class _Ty>
constexpr bool is_move_constructible_v = __is_constructible(_Ty, _Ty);

_EXPORT_STD template <class _To, class _From>
struct is_assignable : bool_constant<__is_assignable(_To, _From)> {}; // determine whether _From can be assigned to _To

_EXPORT_STD template <class _To, class _From>
constexpr bool is_assignable_v = __is_assignable(_To, _From);

#if defined(_IS_ASSIGNABLE_NOCHECK_SUPPORTED) && !defined(__CUDACC__)
template <class _To, class _From>
struct _Is_assignable_no_precondition_check : bool_constant<__is_assignable_no_precondition_check(_To, _From)> {};
#else // ^^^ Use intrinsic / intrinsic not supported vvv
template <class _To, class _From>
using _Is_assignable_no_precondition_check = is_assignable<_To, _From>;
#endif // ^^^ intrinsic not supported ^^^

_EXPORT_STD template <class _Ty>
struct is_copy_assignable
    : bool_constant<__is_assignable(add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<const _Ty>)> {
    // determine whether an lvalue const _Ty can be assigned to an lvalue _Ty
};

_EXPORT_STD template <class _Ty>
constexpr bool is_copy_assignable_v = __is_assignable(add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<const _Ty>);

#if defined(_IS_ASSIGNABLE_NOCHECK_SUPPORTED) && !defined(__CUDACC__)
template <class _Ty>
struct _Is_copy_assignable_no_precondition_check
    : bool_constant<__is_assignable_no_precondition_check(
          add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<const _Ty>)> {};

template <class _Ty>
constexpr bool _Is_copy_assignable_unchecked_v =
    __is_assignable_no_precondition_check(add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<const _Ty>);
#else // ^^^ Use intrinsic / intrinsic not supported vvv
template <class _Ty>
using _Is_copy_assignable_no_precondition_check = is_copy_assignable<_Ty>;

template <class _Ty>
constexpr bool _Is_copy_assignable_unchecked_v = is_copy_assignable_v<_Ty>;
#endif // ^^^ intrinsic not supported ^^^

_EXPORT_STD template <class _Ty>
struct is_move_assignable : bool_constant<__is_assignable(add_lvalue_reference_t<_Ty>, _Ty)> {
    // determine whether an rvalue _Ty can be assigned to an lvalue _Ty
};

_EXPORT_STD template <class _Ty>
constexpr bool is_move_assignable_v = __is_assignable(add_lvalue_reference_t<_Ty>, _Ty);

#if defined(_IS_ASSIGNABLE_NOCHECK_SUPPORTED) && !defined(__CUDACC__)
template <class _Ty>
struct _Is_move_assignable_no_precondition_check
    : bool_constant<__is_assignable_no_precondition_check(add_lvalue_reference_t<_Ty>, _Ty)> {};

template <class _Ty>
constexpr bool _Is_move_assignable_unchecked_v =
    __is_assignable_no_precondition_check(add_lvalue_reference_t<_Ty>, _Ty);
#else // ^^^ Use intrinsic / intrinsic not supported vvv
template <class _Ty>
using _Is_move_assignable_no_precondition_check = is_move_assignable<_Ty>;

template <class _Ty>
constexpr bool _Is_move_assignable_unchecked_v = is_move_assignable_v<_Ty>;
#endif // ^^^ intrinsic not supported ^^^

_EXPORT_STD template <class _Ty>
struct is_destructible : bool_constant<__is_destructible(_Ty)> {
    // true iff remove_all_extents_t<_Ty> is a reference type, or can be explicitly destroyed
};

_EXPORT_STD template <class _Ty>
constexpr bool is_destructible_v = __is_destructible(_Ty);

_EXPORT_STD template <class _Ty, class... _Args>
struct is_trivially_constructible : bool_constant<__is_trivially_constructible(_Ty, _Args...)> {
    // determine whether direct-initialization of _Ty with _Args... is trivial
};

_EXPORT_STD template <class _Ty, class... _Args>
constexpr bool is_trivially_constructible_v = __is_trivially_constructible(_Ty, _Args...);

_EXPORT_STD template <class _Ty>
struct is_trivially_copy_constructible
    : bool_constant<__is_trivially_constructible(_Ty, add_lvalue_reference_t<const _Ty>)> {
    // determine whether direct-initialization of _Ty with an lvalue const _Ty is trivial
};

_EXPORT_STD template <class _Ty>
constexpr bool is_trivially_copy_constructible_v = __is_trivially_constructible(_Ty, add_lvalue_reference_t<const _Ty>);

_EXPORT_STD template <class _Ty>
struct is_trivially_default_constructible : bool_constant<__is_trivially_constructible(_Ty)> {
    // determine whether value-initialization of _Ty is trivial
};

_EXPORT_STD template <class _Ty>
constexpr bool is_trivially_default_constructible_v = __is_trivially_constructible(_Ty);

_EXPORT_STD template <class _Ty>
struct is_trivially_move_constructible : bool_constant<__is_trivially_constructible(_Ty, _Ty)> {
    // determine whether direct-initialization of _Ty with an rvalue _Ty is trivial
};

_EXPORT_STD template <class _Ty>
constexpr bool is_trivially_move_constructible_v = __is_trivially_constructible(_Ty, _Ty);

_EXPORT_STD template <class _To, class _From>
struct is_trivially_assignable : bool_constant<__is_trivially_assignable(_To, _From)> {
    // determine whether _From can be trivially assigned to _To
};

_EXPORT_STD template <class _To, class _From>
constexpr bool is_trivially_assignable_v = __is_trivially_assignable(_To, _From);

_EXPORT_STD template <class _Ty>
struct is_trivially_copy_assignable
    : bool_constant<__is_trivially_assignable(add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<const _Ty>)> {
    // determine whether an lvalue const _Ty can be trivially assigned to an lvalue _Ty
};

_EXPORT_STD template <class _Ty>
constexpr bool is_trivially_copy_assignable_v =
    __is_trivially_assignable(add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<const _Ty>);

_EXPORT_STD template <class _Ty>
struct is_trivially_move_assignable : bool_constant<__is_trivially_assignable(add_lvalue_reference_t<_Ty>, _Ty)> {
    // determine whether an rvalue _Ty can be trivially assigned to an lvalue _Ty
};

_EXPORT_STD template <class _Ty>
constexpr bool is_trivially_move_assignable_v = __is_trivially_assignable(add_lvalue_reference_t<_Ty>, _Ty);

_EXPORT_STD template <class _Ty>
struct is_trivially_destructible : bool_constant<__is_trivially_destructible(_Ty)> {
    // determine whether remove_all_extents_t<_Ty> is a reference type or can trivially be explicitly destroyed
};

_EXPORT_STD template <class _Ty>
constexpr bool is_trivially_destructible_v = __is_trivially_destructible(_Ty);

_EXPORT_STD template <class _Ty, class... _Args>
struct is_nothrow_constructible : bool_constant<__is_nothrow_constructible(_Ty, _Args...)> {
    // determine whether direct-initialization of _Ty from _Args... is both valid and not potentially-throwing
};

_EXPORT_STD template <class _Ty, class... _Args>
constexpr bool is_nothrow_constructible_v = __is_nothrow_constructible(_Ty, _Args...);

_EXPORT_STD template <class _Ty>
struct is_nothrow_copy_constructible
    : bool_constant<__is_nothrow_constructible(_Ty, add_lvalue_reference_t<const _Ty>)> {
    // determine whether direct-initialization of _Ty from an lvalue const _Ty is both valid
    // and not potentially-throwing
};

_EXPORT_STD template <class _Ty>
constexpr bool is_nothrow_copy_constructible_v = __is_nothrow_constructible(_Ty, add_lvalue_reference_t<const _Ty>);

_EXPORT_STD template <class _Ty>
struct is_nothrow_default_constructible : bool_constant<__is_nothrow_constructible(_Ty)> {
    // determine whether value-initialization of _Ty is both valid and not potentially-throwing
};

_EXPORT_STD template <class _Ty>
constexpr bool is_nothrow_default_constructible_v = __is_nothrow_constructible(_Ty);

_EXPORT_STD template <class _Ty>
struct is_nothrow_move_constructible : bool_constant<__is_nothrow_constructible(_Ty, _Ty)> {
    // determine whether direct-initialization of _Ty from an rvalue _Ty is both valid and not potentially-throwing
};

_EXPORT_STD template <class _Ty>
constexpr bool is_nothrow_move_constructible_v = __is_nothrow_constructible(_Ty, _Ty);

_EXPORT_STD template <class _To, class _From>
struct is_nothrow_assignable : bool_constant<__is_nothrow_assignable(_To, _From)> {
    // determine whether assignment of _From to _To is both valid and not potentially-throwing
};

_EXPORT_STD template <class _To, class _From>
constexpr bool is_nothrow_assignable_v = __is_nothrow_assignable(_To, _From);

_EXPORT_STD template <class _Ty>
struct is_nothrow_copy_assignable
    : bool_constant<__is_nothrow_assignable(add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<const _Ty>)> {
    // determine whether assignment of an lvalue const _Ty to an lvalue _Ty is both valid and not potentially-throwing
};

_EXPORT_STD template <class _Ty>
constexpr bool is_nothrow_copy_assignable_v =
    __is_nothrow_assignable(add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<const _Ty>);

_EXPORT_STD template <class _Ty>
struct is_nothrow_move_assignable : bool_constant<__is_nothrow_assignable(add_lvalue_reference_t<_Ty>, _Ty)> {
    // determine whether assignment of an rvalue _Ty to an lvalue _Ty is both valid and not potentially-throwing
};

_EXPORT_STD template <class _Ty>
constexpr bool is_nothrow_move_assignable_v = __is_nothrow_assignable(add_lvalue_reference_t<_Ty>, _Ty);

_EXPORT_STD template <class _Ty>
struct is_nothrow_destructible : bool_constant<__is_nothrow_destructible(_Ty)> {
    // determine whether remove_all_extents_t<_Ty> is a reference type or has
    // non-potentially-throwing explicit destruction
};

_EXPORT_STD template <class _Ty>
constexpr bool is_nothrow_destructible_v = __is_nothrow_destructible(_Ty);

template <class _Ty, bool = is_integral_v<_Ty>>
struct _Sign_base { // determine whether integral type _Ty is signed or unsigned
    using _Uty = remove_cv_t<_Ty>;

    static constexpr bool _Signed   = static_cast<_Uty>(-1) < static_cast<_Uty>(0);
    static constexpr bool _Unsigned = !_Signed;
};

template <class _Ty>
struct _Sign_base<_Ty, false> { // floating-point _Ty is signed
                                // non-arithmetic _Ty is neither signed nor unsigned
    static constexpr bool _Signed   = is_floating_point_v<_Ty>;
    static constexpr bool _Unsigned = false;
};

_EXPORT_STD template <class _Ty>
struct is_signed : bool_constant<_Sign_base<_Ty>::_Signed> {}; // determine whether _Ty is a signed type

_EXPORT_STD template <class _Ty>
constexpr bool is_signed_v = _Sign_base<_Ty>::_Signed;

_EXPORT_STD template <class _Ty>
struct is_unsigned : bool_constant<_Sign_base<_Ty>::_Unsigned> {}; // determine whether _Ty is an unsigned type

_EXPORT_STD template <class _Ty>
constexpr bool is_unsigned_v = _Sign_base<_Ty>::_Unsigned;

template <class _Ty>
constexpr bool _Is_nonbool_integral = is_integral_v<_Ty> && !is_same_v<remove_cv_t<_Ty>, bool>;

template <bool>
struct _Select { // Select between aliases that extract either their first or second parameter
    template <class _Ty1, class>
    using _Apply = _Ty1;
};

template <>
struct _Select<false> {
    template <class, class _Ty2>
    using _Apply = _Ty2;
};

template <size_t>
struct _Make_signed2; // Choose make_signed strategy by type size

template <>
struct _Make_signed2<1> {
    template <class>
    using _Apply = signed char;
};

template <>
struct _Make_signed2<2> {
    template <class>
    using _Apply = short;
};

template <>
struct _Make_signed2<4> {
    template <class _Ty>
    using _Apply = // assumes LLP64
        typename _Select<is_same_v<_Ty, long> || is_same_v<_Ty, unsigned long>>::template _Apply<long, int>;
};

template <>
struct _Make_signed2<8> {
    template <class>
    using _Apply = long long;
};

template <class _Ty>
using _Make_signed1 = // signed partner to cv-unqualified _Ty
    typename _Make_signed2<sizeof(_Ty)>::template _Apply<_Ty>;

_EXPORT_STD template <class _Ty>
struct make_signed { // signed partner to _Ty
    static_assert(_Is_nonbool_integral<_Ty> || is_enum_v<_Ty>,
        "make_signed<T> requires that T shall be a (possibly cv-qualified) "
        "integral type or enumeration but not a bool type.");

    using type = typename remove_cv<_Ty>::template _Apply<_Make_signed1>;
};

_EXPORT_STD template <class _Ty>
using make_signed_t = typename make_signed<_Ty>::type;

template <size_t>
struct _Make_unsigned2; // Choose make_unsigned strategy by type size

template <>
struct _Make_unsigned2<1> {
    template <class>
    using _Apply = unsigned char;
};

template <>
struct _Make_unsigned2<2> {
    template <class>
    using _Apply = unsigned short;
};

template <>
struct _Make_unsigned2<4> {
    template <class _Ty>
    using _Apply = // assumes LLP64
        typename _Select<is_same_v<_Ty, long> || is_same_v<_Ty, unsigned long>>::template _Apply<unsigned long,
            unsigned int>;
};

template <>
struct _Make_unsigned2<8> {
    template <class>
    using _Apply = unsigned long long;
};

template <class _Ty>
using _Make_unsigned1 = // unsigned partner to cv-unqualified _Ty
    typename _Make_unsigned2<sizeof(_Ty)>::template _Apply<_Ty>;

_EXPORT_STD template <class _Ty>
struct make_unsigned { // unsigned partner to _Ty
    static_assert(_Is_nonbool_integral<_Ty> || is_enum_v<_Ty>,
        "make_unsigned<T> requires that T shall be a (possibly cv-qualified) "
        "integral type or enumeration but not a bool type.");

    using type = typename remove_cv<_Ty>::template _Apply<_Make_unsigned1>;
};

_EXPORT_STD template <class _Ty>
using make_unsigned_t = typename make_unsigned<_Ty>::type;

template <class _Rep>
constexpr make_unsigned_t<_Rep> _Unsigned_value(_Rep _Val) { // makes _Val unsigned
    return static_cast<make_unsigned_t<_Rep>>(_Val);
}

_EXPORT_STD template <class _Ty>
struct alignment_of : integral_constant<size_t, alignof(_Ty)> {}; // determine alignment of _Ty

_EXPORT_STD template <class _Ty>
constexpr size_t alignment_of_v = alignof(_Ty);

template <class _Ty, size_t _Len>
union _Align_type { // union with size _Len bytes and alignment of _Ty
    _Ty _Val;
    char _Pad[_Len];
};

template <size_t _Len, size_t _Align, class _Ty, bool _Ok>
struct _Aligned; // define type with size _Len and alignment _Ty

template <size_t _Len, size_t _Align, class _Ty>
struct _Aligned<_Len, _Align, _Ty, true> {
    using type = _Align_type<_Ty, _Len>;
};

template <size_t _Len, size_t _Align>
struct _Aligned<_Len, _Align, double, false> {
#ifdef _ENABLE_EXTENDED_ALIGNED_STORAGE
    struct type {
        alignas(_Align) char _Space[_Len];
    };
#else // ^^^ defined(_ENABLE_EXTENDED_ALIGNED_STORAGE) / !defined(_ENABLE_EXTENDED_ALIGNED_STORAGE) vvv
#ifndef _DISABLE_EXTENDED_ALIGNED_STORAGE
    static_assert(_Always_false<_Aligned>,
        "You've instantiated std::aligned_storage<Len, Align> with an extended alignment (in other "
        "words, Align > alignof(max_align_t)). Before VS 2017 15.8, the member \"type\" would "
        "non-conformingly have an alignment of only alignof(max_align_t). VS 2017 15.8 was fixed to "
        "handle this correctly, but the fix inherently changes layout and breaks binary compatibility "
        "(*only* for uses of aligned_storage with extended alignments). "
        "To suppress this error, please define either "
        "(1) _ENABLE_EXTENDED_ALIGNED_STORAGE to confirm that you want a type with an extended alignment, or "
        "(2) _DISABLE_EXTENDED_ALIGNED_STORAGE to get the old non-conforming behavior.");
#endif // ^^^ !defined(_DISABLE_EXTENDED_ALIGNED_STORAGE) ^^^
    using type = _Align_type<max_align_t, _Len>;
#endif // ^^^ !defined(_ENABLE_EXTENDED_ALIGNED_STORAGE) ^^^
};

template <size_t _Len, size_t _Align>
struct _Aligned<_Len, _Align, int, false> {
    using _Next                 = double;
    static constexpr bool _Fits = _Align <= alignof(_Next);
    using type                  = typename _Aligned<_Len, _Align, _Next, _Fits>::type;
};

template <size_t _Len, size_t _Align>
struct _Aligned<_Len, _Align, short, false> {
    using _Next                 = int;
    static constexpr bool _Fits = _Align <= alignof(_Next);
    using type                  = typename _Aligned<_Len, _Align, _Next, _Fits>::type;
};

template <size_t _Len, size_t _Align>
struct _Aligned<_Len, _Align, char, false> {
    using _Next                 = short;
    static constexpr bool _Fits = _Align <= alignof(_Next);
    using type                  = typename _Aligned<_Len, _Align, _Next, _Fits>::type;
};

// TRANSITION, ABI: Internal non-deprecated version to avoid ABI changes due to deprecation
template <size_t _Len, size_t _Align = alignof(max_align_t)>
struct _Aligned_storage { // define type with size _Len and alignment _Align
    using _Next                 = char;
    static constexpr bool _Fits = _Align <= alignof(_Next);
    using type                  = typename _Aligned<_Len, _Align, _Next, _Fits>::type;
};

template <size_t _Len, size_t _Align = alignof(max_align_t)>
using _Aligned_storage_t = typename _Aligned_storage<_Len, _Align>::type;

_EXPORT_STD template <size_t _Len, size_t _Align = alignof(max_align_t)>
struct _CXX23_DEPRECATE_ALIGNED_STORAGE aligned_storage { // define type with size _Len and alignment _Align
    using type = _Aligned_storage_t<_Len, _Align>;
};

_EXPORT_STD template <size_t _Len, size_t _Align = alignof(max_align_t)>
using aligned_storage_t _CXX23_DEPRECATE_ALIGNED_STORAGE = _Aligned_storage_t<_Len, _Align>;

template <size_t... _Vals>
struct _Maximum;

template <>
struct _Maximum<> : integral_constant<size_t, 0> {}; // maximum of nothing is 0

template <size_t _Val>
struct _Maximum<_Val> : integral_constant<size_t, _Val> {}; // maximum of _Val is _Val

template <size_t _First, size_t _Second, size_t... _Rest>
struct _Maximum<_First, _Second, _Rest...> : _Maximum<(_First < _Second ? _Second : _First), _Rest...>::type {
    // find maximum value in _First, _Second, _Rest...
};

_EXPORT_STD template <size_t _Len, class... _Types>
struct _CXX23_DEPRECATE_ALIGNED_UNION aligned_union {
    // define type with size at least _Len, for storing anything in _Types
    static constexpr size_t _Max_len        = _Maximum<_Len, sizeof(_Types)...>::value; // NOT sizeof...(_Types)
    static constexpr size_t alignment_value = _Maximum<alignof(_Types)...>::value;

    using type = _Aligned_storage_t<_Max_len, alignment_value>;
};

_STL_DISABLE_DEPRECATED_WARNING
_EXPORT_STD template <size_t _Len, class... _Types>
using aligned_union_t _CXX23_DEPRECATE_ALIGNED_UNION = typename aligned_union<_Len, _Types...>::type;
_STL_RESTORE_DEPRECATED_WARNING

template <class _Ty, bool = is_enum_v<_Ty>>
struct _Underlying_type {
    using type = __underlying_type(_Ty);
};

template <class _Ty>
struct _Underlying_type<_Ty, false> {};

_EXPORT_STD template <class _Ty>
struct underlying_type : _Underlying_type<_Ty> {}; // determine underlying type for enum

_EXPORT_STD template <class _Ty>
using underlying_type_t = typename _Underlying_type<_Ty>::type;

_EXPORT_STD template <class _Ty>
constexpr size_t rank_v = 0; // determine number of dimensions of array _Ty

template <class _Ty, size_t _Nx>
constexpr size_t rank_v<_Ty[_Nx]> = rank_v<_Ty> + 1;

template <class _Ty>
constexpr size_t rank_v<_Ty[]> = rank_v<_Ty> + 1;

_EXPORT_STD template <class _Ty>
struct rank : integral_constant<size_t, rank_v<_Ty>> {};

_EXPORT_STD template <class _Ty, unsigned int _Ix = 0>
constexpr size_t extent_v = 0; // determine extent of dimension _Ix of array _Ty

template <class _Ty, size_t _Nx>
constexpr size_t extent_v<_Ty[_Nx], 0> = _Nx;

template <class _Ty, unsigned int _Ix, size_t _Nx>
constexpr size_t extent_v<_Ty[_Nx], _Ix> = extent_v<_Ty, _Ix - 1>;

template <class _Ty, unsigned int _Ix>
constexpr size_t extent_v<_Ty[], _Ix> = extent_v<_Ty, _Ix - 1>;

_EXPORT_STD template <class _Ty, unsigned int _Ix = 0>
struct extent : integral_constant<size_t, extent_v<_Ty, _Ix>> {};

_EXPORT_STD template <class _Base, class _Derived>
struct is_base_of : bool_constant<__is_base_of(_Base, _Derived)> {
    // determine whether _Base is a base of or the same as _Derived
};

_EXPORT_STD template <class _Base, class _Derived>
constexpr bool is_base_of_v = __is_base_of(_Base, _Derived);

_EXPORT_STD template <class _Ty>
struct decay { // determines decayed version of _Ty
    using _Ty1 = remove_reference_t<_Ty>;
    using _Ty2 = typename _Select<is_function_v<_Ty1>>::template _Apply<add_pointer<_Ty1>, remove_cv<_Ty1>>;
    using type = typename _Select<is_array_v<_Ty1>>::template _Apply<add_pointer<remove_extent_t<_Ty1>>, _Ty2>::type;
};

_EXPORT_STD template <class _Ty>
using decay_t = typename decay<_Ty>::type;

template <class _Ty1, class _Ty2>
using _Conditional_type = decltype(false ? _STD declval<_Ty1>() : _STD declval<_Ty2>());

#if _HAS_CXX20
template <class _Ty1, class _Ty2, class = void>
struct _Const_lvalue_cond_oper {};

// N4950 [meta.trans.other]/3.3.4 (per the proposed resolution of LWG-3205): "Otherwise, if remove_cvref_t</**/> denotes
// a type..."
template <class _Ty1, class _Ty2>
struct _Const_lvalue_cond_oper<_Ty1, _Ty2, void_t<_Conditional_type<const _Ty1&, const _Ty2&>>> {
    using type = remove_cvref_t<_Conditional_type<const _Ty1&, const _Ty2&>>;
};

template <class _Ty1, class _Ty2, class = void>
struct _Decayed_cond_oper : _Const_lvalue_cond_oper<_Ty1, _Ty2> {};
#else // ^^^ _HAS_CXX20 / !_HAS_CXX20 vvv
template <class _Ty1, class _Ty2, class = void>
struct _Decayed_cond_oper {};
#endif // ^^^ !_HAS_CXX20 ^^^

template <class _Ty1, class _Ty2>
struct _Decayed_cond_oper<_Ty1, _Ty2, void_t<_Conditional_type<_Ty1, _Ty2>>> {
    using type = decay_t<_Conditional_type<_Ty1, _Ty2>>;
};

_EXPORT_STD template <class... _Ty>
struct common_type;

_EXPORT_STD template <class... _Ty>
using common_type_t = typename common_type<_Ty...>::type;

template <>
struct common_type<> {};

template <class _Ty1>
struct common_type<_Ty1> : common_type<_Ty1, _Ty1> {};

template <class _Ty1, class _Ty2, class _Decayed1 = decay_t<_Ty1>, class _Decayed2 = decay_t<_Ty2>>
struct _Common_type2 : common_type<_Decayed1, _Decayed2> {};

template <class _Ty1, class _Ty2>
struct _Common_type2<_Ty1, _Ty2, _Ty1, _Ty2> : _Decayed_cond_oper<_Ty1, _Ty2> {};

template <class _Ty1, class _Ty2>
struct common_type<_Ty1, _Ty2> : _Common_type2<_Ty1, _Ty2> {};

template <class _Void, class _Ty1, class _Ty2, class... _Rest>
struct _Common_type3 {};

template <class _Ty1, class _Ty2, class... _Rest>
struct _Common_type3<void_t<common_type_t<_Ty1, _Ty2>>, _Ty1, _Ty2, _Rest...>
    : common_type<common_type_t<_Ty1, _Ty2>, _Rest...> {};

template <class _Ty1, class _Ty2, class... _Rest>
struct common_type<_Ty1, _Ty2, _Rest...> : _Common_type3<void, _Ty1, _Ty2, _Rest...> {};

template <class _Ty>
_Ty _Returns_exactly() noexcept; // not defined

#if _HAS_CXX20
_EXPORT_STD template <class, class, template <class> class, template <class> class>
struct basic_common_reference {};

template <class _From>
struct _Copy_cv_impl {
    template <class _To>
    using _Apply = _To;
};
template <class _From>
struct _Copy_cv_impl<const _From> {
    template <class _To>
    using _Apply = const _To;
};
template <class _From>
struct _Copy_cv_impl<volatile _From> {
    template <class _To>
    using _Apply = volatile _To;
};
template <class _From>
struct _Copy_cv_impl<const volatile _From> {
    template <class _To>
    using _Apply = const volatile _To;
};
template <class _From, class _To>
using _Copy_cv = // N4950 [meta.trans.other]/2.3
    _Copy_cv_impl<_From>::template _Apply<_To>;

template <class _Ty1>
struct _Add_qualifiers { // _Add_qualifiers<A>::template _Apply is XREF(A) from N4950 [meta.trans.other]/2.2
    template <class _Ty2>
    using _Apply = _Copy_cv<_Ty1, _Ty2>;
};
template <class _Ty1>
struct _Add_qualifiers<_Ty1&> {
    template <class _Ty2>
    using _Apply = add_lvalue_reference_t<_Copy_cv<_Ty1, _Ty2>>;
};
template <class _Ty1>
struct _Add_qualifiers<_Ty1&&> {
    template <class _Ty2>
    using _Apply = add_rvalue_reference_t<_Copy_cv<_Ty1, _Ty2>>;
};

template <class _Ty1, class _Ty2>
using _Cond_res = // N4950 [meta.trans.other]/2.4
    decltype(false ? _Returns_exactly<_Ty1>() : _Returns_exactly<_Ty2>());

_EXPORT_STD template <class...>
struct common_reference;

_EXPORT_STD template <class... _Types>
using common_reference_t = common_reference<_Types...>::type;

// N4950 [meta.trans.other]/5.1: "If sizeof...(T) is zero ..."
template <>
struct common_reference<> {};

// N4950 [meta.trans.other]/5.2: "...if sizeof...(T) is one ..."
template <class _Ty>
struct common_reference<_Ty> {
    using type = _Ty;
};

// N4950 [meta.trans.other]/5.3: "...if sizeof...(T) is two..."

// N4950 [meta.trans.other]/5.3.4: "if common_type_t<T1, T2> is well-formed..."
// N4950 [meta.trans.other]/5.3.5: "Otherwise, there shall be no member type."
template <class _Ty1, class _Ty2, class = void>
struct _Common_reference2C : common_type<_Ty1, _Ty2> {};

// N4950 [meta.trans.other]/5.3.3: "if COND_RES(T1, T2) is well-formed..."
template <class _Ty1, class _Ty2>
struct _Common_reference2C<_Ty1, _Ty2, void_t<_Cond_res<_Ty1, _Ty2>>> {
    using type = _Cond_res<_Ty1, _Ty2>;
};

// N4950 [meta.trans.other]/5.3.2: "if basic_common_reference<[...]>::type is well-formed..."
template <class _Ty1, class _Ty2>
using _Basic_specialization = basic_common_reference<remove_cvref_t<_Ty1>, remove_cvref_t<_Ty2>,
    _Add_qualifiers<_Ty1>::template _Apply, _Add_qualifiers<_Ty2>::template _Apply>::type;

template <class _Ty1, class _Ty2, class = void>
struct _Common_reference2B : _Common_reference2C<_Ty1, _Ty2> {};

template <class _Ty1, class _Ty2>
struct _Common_reference2B<_Ty1, _Ty2, void_t<_Basic_specialization<_Ty1, _Ty2>>> {
    using type = _Basic_specialization<_Ty1, _Ty2>;
};

// N4950 [meta.trans.other]/5.3.1: "Let R be COMMON-REF(T1, T2). If T1 and T2 are reference types, R is well-formed, and
// is_convertible_v<add_pointer_t<T1>, add_pointer_t<R>> && is_convertible_v<add_pointer_t<T2>, add_pointer_t<R>> is
// true, then the member typedef type denotes R."
template <class _Ty1, class _Ty2, class = void>
struct _Common_reference2A : _Common_reference2B<_Ty1, _Ty2> {};

template <class _Ty1, class _Ty2, class _Result = _Cond_res<_Copy_cv<_Ty1, _Ty2>&, _Copy_cv<_Ty2, _Ty1>&>,
    enable_if_t<is_lvalue_reference_v<_Result>, int> = 0>
using _LL_common_ref = _Result;

template <class _Ty1, class _Ty2, class = void>
struct _Common_reference2AX {};

template <class _Ty1, class _Ty2>
struct _Common_reference2AX<_Ty1&, _Ty2&, void_t<_LL_common_ref<_Ty1, _Ty2>>> {
    using type = _LL_common_ref<_Ty1, _Ty2>; // "both lvalues" case from N4950 [meta.trans.other]/2.5
};

template <class _Ty1, class _Ty2>
struct _Common_reference2AX<_Ty1&&, _Ty2&, enable_if_t<is_convertible_v<_Ty1&&, _LL_common_ref<const _Ty1, _Ty2>>>> {
    using type = _LL_common_ref<const _Ty1, _Ty2>; // "rvalue and lvalue" case from N4950 [meta.trans.other]/2.7
};

template <class _Ty1, class _Ty2>
struct _Common_reference2AX<_Ty1&, _Ty2&&, enable_if_t<is_convertible_v<_Ty2&&, _LL_common_ref<const _Ty2, _Ty1>>>> {
    using type = _LL_common_ref<const _Ty2, _Ty1>; // "lvalue and rvalue" case from N4950 [meta.trans.other]/2.8
};

template <class _Ty1, class _Ty2>
using _RR_common_ref = remove_reference_t<_LL_common_ref<_Ty1, _Ty2>>&&;

template <class _Ty1, class _Ty2>
struct _Common_reference2AX<_Ty1&&, _Ty2&&,
    enable_if_t<is_convertible_v<_Ty1&&, _RR_common_ref<_Ty1, _Ty2>>
                && is_convertible_v<_Ty2&&, _RR_common_ref<_Ty1, _Ty2>>>> {
    using type = _RR_common_ref<_Ty1, _Ty2>; // "both rvalues" case from N4950 [meta.trans.other]/2.6
};

template <class _Ty1, class _Ty2>
using _Common_ref_2AX_t = _Common_reference2AX<_Ty1, _Ty2>::type;

template <class _Ty1, class _Ty2>
struct _Common_reference2A<_Ty1, _Ty2,
    enable_if_t<is_convertible_v<add_pointer_t<_Ty1>, add_pointer_t<_Common_ref_2AX_t<_Ty1, _Ty2>>>
                && is_convertible_v<add_pointer_t<_Ty2>, add_pointer_t<_Common_ref_2AX_t<_Ty1, _Ty2>>>>> {
    using type = _Common_ref_2AX_t<_Ty1, _Ty2>;
};

template <class _Ty1, class _Ty2>
struct common_reference<_Ty1, _Ty2> : _Common_reference2A<_Ty1, _Ty2> {};

// N4950 [meta.trans.other]/5.4: "if sizeof...(T) is greater than two..."
template <class _Void, class _Ty1, class _Ty2, class... _Types>
struct _Fold_common_reference {};
template <class _Ty1, class _Ty2, class... _Types>
struct _Fold_common_reference<void_t<common_reference_t<_Ty1, _Ty2>>, _Ty1, _Ty2, _Types...>
    : common_reference<common_reference_t<_Ty1, _Ty2>, _Types...> {};

template <class _Ty1, class _Ty2, class _Ty3, class... _Rest>
struct common_reference<_Ty1, _Ty2, _Ty3, _Rest...> : _Fold_common_reference<void, _Ty1, _Ty2, _Ty3, _Rest...> {};

_EXPORT_STD template <class _Ty>
struct type_identity {
    using type = _Ty;
};
_EXPORT_STD template <class _Ty>
using type_identity_t = type_identity<_Ty>::type;
#endif // _HAS_CXX20

template <class _Type, template <class...> class _Template>
constexpr bool _Is_specialization_v = false; // true if and only if _Type is a specialization of _Template
template <template <class...> class _Template, class... _Types>
constexpr bool _Is_specialization_v<_Template<_Types...>, _Template> = true;

template <class _Type, template <class...> class _Template>
struct _Is_specialization : bool_constant<_Is_specialization_v<_Type, _Template>> {};

_EXPORT_STD template <class _Ty>
_NODISCARD _MSVC_INTRINSIC constexpr _Ty&& forward(remove_reference_t<_Ty>& _Arg) noexcept {
    return static_cast<_Ty&&>(_Arg);
}

_EXPORT_STD template <class _Ty>
_NODISCARD _MSVC_INTRINSIC constexpr _Ty&& forward(remove_reference_t<_Ty>&& _Arg) noexcept {
    static_assert(!is_lvalue_reference_v<_Ty>, "bad forward call");
    return static_cast<_Ty&&>(_Arg);
}

_EXPORT_STD template <class _Ty>
_NODISCARD _MSVC_INTRINSIC constexpr remove_reference_t<_Ty>&& move(_Ty&& _Arg) noexcept {
    return static_cast<remove_reference_t<_Ty>&&>(_Arg);
}

_EXPORT_STD template <class _Ty>
_NODISCARD _MSVC_INTRINSIC constexpr //
    conditional_t<!is_nothrow_move_constructible_v<_Ty> && is_copy_constructible_v<_Ty>, const _Ty&, _Ty&&>
    move_if_noexcept(_Ty& _Arg) noexcept {
    return _STD move(_Arg);
}

_EXPORT_STD template <class _Ty>
_NODISCARD constexpr _Ty* addressof(_Ty& _Val) noexcept {
    return __builtin_addressof(_Val);
}

_EXPORT_STD template <class _Ty>
const _Ty* addressof(const _Ty&&) = delete;

#pragma warning(push)
#pragma warning(disable : 5215) // '%s' a function parameter with a volatile qualified type is deprecated in C++20
#pragma warning(disable : 5216) // '%s' a volatile qualified return type is deprecated in C++20

#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-volatile"
#endif // defined(__clang__)

template <class _Ty>
_NODISCARD _Ty _Fake_copy_init(_Ty) noexcept;
// _Fake_copy_init<T>(E):
// (1) has type T [decay_t<decltype((E))> if T is deduced],
// (2) is well-formed if and only if E is implicitly convertible to T and T is destructible, and
// (3) is non-throwing if and only if both conversion from decltype((E)) to T and destruction of T are non-throwing.

#ifdef __clang__
#pragma clang diagnostic pop
#endif // defined(__clang__)

#pragma warning(pop)

_EXPORT_STD template <class _Ty>
class reference_wrapper;

// std::invoke isn't constexpr in C++17, and normally implementers are forbidden from "strengthening" constexpr
// (N4950 [constexpr.functions]/1), yet both std::apply and std::visit are required to be constexpr and have
// invoke-like behavior. As a result, we've chosen to apply the part of P1065R2 resolving LWG-2894 as a defect report.

enum class _Invoker_strategy {
    _Functor,
    _Pmf_object,
    _Pmf_refwrap,
    _Pmf_pointer,
    _Pmd_object,
    _Pmd_refwrap,
    _Pmd_pointer
};

struct _Invoker_functor {
    static constexpr _Invoker_strategy _Strategy = _Invoker_strategy::_Functor;

    template <class _Callable, class... _Types>
    static constexpr auto _Call(_Callable&& _Obj, _Types&&... _Args) noexcept(
        noexcept(static_cast<_Callable&&>(_Obj)(static_cast<_Types&&>(_Args)...)))
        -> decltype(static_cast<_Callable&&>(_Obj)(static_cast<_Types&&>(_Args)...)) {
        return static_cast<_Callable&&>(_Obj)(static_cast<_Types&&>(_Args)...);
    }
};

struct _Invoker_pmf_object {
    static constexpr _Invoker_strategy _Strategy = _Invoker_strategy::_Pmf_object;

    template <class _Decayed, class _Ty1, class... _Types2>
    static constexpr auto _Call(_Decayed _Pmf, _Ty1&& _Arg1, _Types2&&... _Args2) noexcept(
        noexcept((static_cast<_Ty1&&>(_Arg1).*_Pmf)(static_cast<_Types2&&>(_Args2)...)))
        -> decltype((static_cast<_Ty1&&>(_Arg1).*_Pmf)(static_cast<_Types2&&>(_Args2)...)) {
        return (static_cast<_Ty1&&>(_Arg1).*_Pmf)(static_cast<_Types2&&>(_Args2)...);
    }
};

struct _Invoker_pmf_refwrap {
    static constexpr _Invoker_strategy _Strategy = _Invoker_strategy::_Pmf_refwrap;

    template <class _Decayed, class _Refwrap, class... _Types2>
    static constexpr auto _Call(_Decayed _Pmf, _Refwrap _Rw, _Types2&&... _Args2) noexcept(
        noexcept((_Rw.get().*_Pmf)(static_cast<_Types2&&>(_Args2)...)))
        -> decltype((_Rw.get().*_Pmf)(static_cast<_Types2&&>(_Args2)...)) {
        return (_Rw.get().*_Pmf)(static_cast<_Types2&&>(_Args2)...);
    }
};

struct _Invoker_pmf_pointer {
    static constexpr _Invoker_strategy _Strategy = _Invoker_strategy::_Pmf_pointer;

    template <class _Decayed, class _Ty1, class... _Types2>
    static constexpr auto _Call(_Decayed _Pmf, _Ty1&& _Arg1, _Types2&&... _Args2) noexcept(
        noexcept(((*static_cast<_Ty1&&>(_Arg1)).*_Pmf)(static_cast<_Types2&&>(_Args2)...)))
        -> decltype(((*static_cast<_Ty1&&>(_Arg1)).*_Pmf)(static_cast<_Types2&&>(_Args2)...)) {
        return ((*static_cast<_Ty1&&>(_Arg1)).*_Pmf)(static_cast<_Types2&&>(_Args2)...);
    }
};

struct _Invoker_pmd_object {
    static constexpr _Invoker_strategy _Strategy = _Invoker_strategy::_Pmd_object;

    template <class _Decayed, class _Ty1>
    static constexpr auto _Call(_Decayed _Pmd, _Ty1&& _Arg1) noexcept -> decltype(static_cast<_Ty1&&>(_Arg1).*_Pmd) {
        return static_cast<_Ty1&&>(_Arg1).*_Pmd;
    }
};

struct _Invoker_pmd_refwrap {
    static constexpr _Invoker_strategy _Strategy = _Invoker_strategy::_Pmd_refwrap;

    template <class _Decayed, class _Refwrap>
    static constexpr auto _Call(_Decayed _Pmd, _Refwrap _Rw) noexcept -> decltype(_Rw.get().*_Pmd) {
        return _Rw.get().*_Pmd;
    }
};

struct _Invoker_pmd_pointer {
    static constexpr _Invoker_strategy _Strategy = _Invoker_strategy::_Pmd_pointer;

    template <class _Decayed, class _Ty1>
    static constexpr auto _Call(_Decayed _Pmd, _Ty1&& _Arg1) noexcept(noexcept((*static_cast<_Ty1&&>(_Arg1)).*_Pmd))
        -> decltype((*static_cast<_Ty1&&>(_Arg1)).*_Pmd) {
        return (*static_cast<_Ty1&&>(_Arg1)).*_Pmd;
    }
};

template <class _Callable, class _Ty1, class _Removed_cvref = _Remove_cvref_t<_Callable>,
    bool _Is_pmf = is_member_function_pointer_v<_Removed_cvref>,
    bool _Is_pmd = is_member_object_pointer_v<_Removed_cvref>>
struct _Invoker1;

template <class _Callable, class _Ty1, class _Removed_cvref>
struct _Invoker1<_Callable, _Ty1, _Removed_cvref, true, false>
    : conditional_t<is_same_v<typename _Is_memfunptr<_Removed_cvref>::_Class_type, _Remove_cvref_t<_Ty1>>
                        || is_base_of_v<typename _Is_memfunptr<_Removed_cvref>::_Class_type, _Remove_cvref_t<_Ty1>>,
          _Invoker_pmf_object,
          conditional_t<_Is_specialization_v<_Remove_cvref_t<_Ty1>, reference_wrapper>, _Invoker_pmf_refwrap,
              _Invoker_pmf_pointer>> {}; // pointer to member function

template <class _Callable, class _Ty1, class _Removed_cvref>
struct _Invoker1<_Callable, _Ty1, _Removed_cvref, false, true>
    : conditional_t<
          is_same_v<typename _Is_member_object_pointer<_Removed_cvref>::_Class_type, _Remove_cvref_t<_Ty1>>
              || is_base_of_v<typename _Is_member_object_pointer<_Removed_cvref>::_Class_type, _Remove_cvref_t<_Ty1>>,
          _Invoker_pmd_object,
          conditional_t<_Is_specialization_v<_Remove_cvref_t<_Ty1>, reference_wrapper>, _Invoker_pmd_refwrap,
              _Invoker_pmd_pointer>> {}; // pointer to member data

template <class _Callable, class _Ty1, class _Removed_cvref>
struct _Invoker1<_Callable, _Ty1, _Removed_cvref, false, false> : _Invoker_functor {};

_EXPORT_STD template <class _Callable>
constexpr auto invoke(_Callable&& _Obj) noexcept(noexcept(static_cast<_Callable&&>(_Obj)()))
    -> decltype(static_cast<_Callable&&>(_Obj)()) {
    return static_cast<_Callable&&>(_Obj)();
}

_EXPORT_STD template <class _Callable, class _Ty1, class... _Types2>
constexpr auto invoke(_Callable&& _Obj, _Ty1&& _Arg1, _Types2&&... _Args2) noexcept(
    noexcept(_Invoker1<_Callable, _Ty1>::_Call(
        static_cast<_Callable&&>(_Obj), static_cast<_Ty1&&>(_Arg1), static_cast<_Types2&&>(_Args2)...)))
    -> decltype(_Invoker1<_Callable, _Ty1>::_Call(
        static_cast<_Callable&&>(_Obj), static_cast<_Ty1&&>(_Arg1), static_cast<_Types2&&>(_Args2)...)) {
    if constexpr (_Invoker1<_Callable, _Ty1>::_Strategy == _Invoker_strategy::_Functor) {
        return static_cast<_Callable&&>(_Obj)(static_cast<_Ty1&&>(_Arg1), static_cast<_Types2&&>(_Args2)...);
    } else if constexpr (_Invoker1<_Callable, _Ty1>::_Strategy == _Invoker_strategy::_Pmf_object) {
        return (static_cast<_Ty1&&>(_Arg1).*_Obj)(static_cast<_Types2&&>(_Args2)...);
    } else if constexpr (_Invoker1<_Callable, _Ty1>::_Strategy == _Invoker_strategy::_Pmf_refwrap) {
        return (_Arg1.get().*_Obj)(static_cast<_Types2&&>(_Args2)...);
    } else if constexpr (_Invoker1<_Callable, _Ty1>::_Strategy == _Invoker_strategy::_Pmf_pointer) {
        return ((*static_cast<_Ty1&&>(_Arg1)).*_Obj)(static_cast<_Types2&&>(_Args2)...);
    } else if constexpr (_Invoker1<_Callable, _Ty1>::_Strategy == _Invoker_strategy::_Pmd_object) {
        return static_cast<_Ty1&&>(_Arg1).*_Obj;
    } else if constexpr (_Invoker1<_Callable, _Ty1>::_Strategy == _Invoker_strategy::_Pmd_refwrap) {
#if defined(__clang__) || defined(__EDG__) // TRANSITION, VSO-1956799
        return _Arg1.get().*_Obj;
#else // ^^^ no workaround / workaround vvv
        auto& _Ref = _Arg1.get();
        return _Ref.*_Obj;
#endif // ^^^ workaround ^^^
    } else {
        _STL_INTERNAL_STATIC_ASSERT(_Invoker1<_Callable, _Ty1>::_Strategy == _Invoker_strategy::_Pmd_pointer);
        return (*static_cast<_Ty1&&>(_Arg1)).*_Obj;
    }
}

#pragma warning(push)
#pragma warning(disable : 4242) // '%s': conversion from '%s' to '%s', possible loss of data (/Wall)
#pragma warning(disable : 4244) // '%s': conversion from '%s' to '%s', possible loss of data (Yes, duplicated message.)
#pragma warning(disable : 4365) // '%s': conversion from '%s' to '%s', signed/unsigned mismatch (/Wall)

template <class _From, class _To, bool = is_convertible_v<_From, _To>, bool = is_void_v<_To>>
constexpr bool _Is_nothrow_convertible_v = noexcept(_STD _Fake_copy_init<_To>(_STD declval<_From>()));

#pragma warning(pop)

template <class _From, class _To, bool _IsVoid>
constexpr bool _Is_nothrow_convertible_v<_From, _To, false, _IsVoid> = false;

template <class _From, class _To>
constexpr bool _Is_nothrow_convertible_v<_From, _To, true, true> = true;

template <class _From, class _To>
struct _Is_nothrow_convertible : bool_constant<_Is_nothrow_convertible_v<_From, _To>> {
    // determine whether _From is nothrow-convertible to _To
};

#if _HAS_CXX20
_EXPORT_STD template <class _From, class _To>
constexpr bool is_nothrow_convertible_v = _Is_nothrow_convertible_v<_From, _To>;

_EXPORT_STD template <class _From, class _To>
struct is_nothrow_convertible : bool_constant<_Is_nothrow_convertible_v<_From, _To>> {};
#endif // _HAS_CXX20

template <class _From, class _To, class = void>
struct _Invoke_convertible : false_type {};

template <class _From, class _To>
struct _Invoke_convertible<_From, _To, void_t<decltype(_STD _Fake_copy_init<_To>(_STD _Returns_exactly<_From>()))>>
    : true_type {};

template <class _From, class _To>
struct _Invoke_nothrow_convertible
    : bool_constant<noexcept(_STD _Fake_copy_init<_To>(_STD _Returns_exactly<_From>()))> {};

template <class _Result, bool _Nothrow>
struct _Invoke_traits_common {
    using type                  = _Result;
    using _Is_invocable         = true_type;
    using _Is_nothrow_invocable = bool_constant<_Nothrow>;
    template <class _Rx>
    using _Is_invocable_r = bool_constant<disjunction_v<is_void<_Rx>, _Invoke_convertible<type, _Rx>>>;
    template <class _Rx>
    using _Is_nothrow_invocable_r = bool_constant<conjunction_v<_Is_nothrow_invocable,
        disjunction<is_void<_Rx>,
            conjunction<_Invoke_convertible<type, _Rx>, _Invoke_nothrow_convertible<type, _Rx>>>>>;
};

template <class _Void, class _Callable>
struct _Invoke_traits_zero {
    // selected when _Callable isn't callable with zero _Args
    using _Is_invocable         = false_type;
    using _Is_nothrow_invocable = false_type;
    template <class _Rx>
    using _Is_invocable_r = false_type;
    template <class _Rx>
    using _Is_nothrow_invocable_r = false_type;
};

template <class _Callable>
using _Decltype_invoke_zero = decltype(_STD declval<_Callable>()());

template <class _Callable>
struct _Invoke_traits_zero<void_t<_Decltype_invoke_zero<_Callable>>, _Callable>
    : _Invoke_traits_common<_Decltype_invoke_zero<_Callable>, noexcept(_STD declval<_Callable>()())> {};

template <class _Void, class... _Types>
struct _Invoke_traits_nonzero {
    // selected when _Callable isn't callable with nonzero _Args
    using _Is_invocable         = false_type;
    using _Is_nothrow_invocable = false_type;
    template <class _Rx>
    using _Is_invocable_r = false_type;
    template <class _Rx>
    using _Is_nothrow_invocable_r = false_type;
};

template <class _Callable, class _Ty1, class... _Types2>
using _Decltype_invoke_nonzero = decltype(_Invoker1<_Callable, _Ty1>::_Call(
    _STD declval<_Callable>(), _STD declval<_Ty1>(), _STD declval<_Types2>()...));

template <class _Callable, class _Ty1, class... _Types2>
struct _Invoke_traits_nonzero<void_t<_Decltype_invoke_nonzero<_Callable, _Ty1, _Types2...>>, _Callable, _Ty1,
    _Types2...> : _Invoke_traits_common<_Decltype_invoke_nonzero<_Callable, _Ty1, _Types2...>,
                      noexcept(_Invoker1<_Callable, _Ty1>::_Call(
                          _STD declval<_Callable>(), _STD declval<_Ty1>(), _STD declval<_Types2>()...))> {};

template <class _Callable, class... _Args>
using _Select_invoke_traits = conditional_t<sizeof...(_Args) == 0, _Invoke_traits_zero<void, _Callable>,
    _Invoke_traits_nonzero<void, _Callable, _Args...>>;

#if _HAS_DEPRECATED_RESULT_OF
_EXPORT_STD template <class _Fty>
struct _CXX17_DEPRECATE_RESULT_OF result_of { // explain usage
    static_assert(_Always_false<_Fty>, "result_of<CallableType> is invalid; use "
                                       "result_of<CallableType(zero or more argument types)> instead.");
};

#define _RESULT_OF(CALL_OPT, X1, X2, X3)                                                                    \
    template <class _Callable, class... _Args>                                                              \
    struct _CXX17_DEPRECATE_RESULT_OF result_of<_Callable CALL_OPT(_Args...)>                               \
        : _Select_invoke_traits<_Callable, _Args...> { /* template to determine result of call operation */ \
    };

_NON_MEMBER_CALL(_RESULT_OF, X1, X2, X3)
#undef _RESULT_OF

_STL_DISABLE_DEPRECATED_WARNING
_EXPORT_STD template <class _Ty>
using result_of_t _CXX17_DEPRECATE_RESULT_OF = typename result_of<_Ty>::type;
_STL_RESTORE_DEPRECATED_WARNING
#endif // _HAS_DEPRECATED_RESULT_OF

template <class _Callable, class... _Args>
using _Invoke_result_t = typename _Select_invoke_traits<_Callable, _Args...>::type;

template <class _Rx, class _Callable, class... _Args>
using _Is_invocable_r_ = typename _Select_invoke_traits<_Callable, _Args...>::template _Is_invocable_r<_Rx>;

template <class _Rx, class _Callable, class... _Args>
struct _Is_invocable_r : _Is_invocable_r_<_Rx, _Callable, _Args...> {
    // determines whether _Callable is callable with _Args and return type _Rx
};

#if _HAS_CXX17
_EXPORT_STD template <class _Callable, class... _Args>
struct invoke_result : _Select_invoke_traits<_Callable, _Args...> {
    // determine the result type of invoking _Callable with _Args
};

_EXPORT_STD template <class _Callable, class... _Args>
using invoke_result_t = typename _Select_invoke_traits<_Callable, _Args...>::type;

_EXPORT_STD template <class _Callable, class... _Args>
struct is_invocable : _Select_invoke_traits<_Callable, _Args...>::_Is_invocable {
    // determines whether _Callable is callable with _Args
};

_EXPORT_STD template <class _Callable, class... _Args>
constexpr bool is_invocable_v = _Select_invoke_traits<_Callable, _Args...>::_Is_invocable::value;

_EXPORT_STD template <class _Callable, class... _Args>
struct is_nothrow_invocable : _Select_invoke_traits<_Callable, _Args...>::_Is_nothrow_invocable {
    // determines whether _Callable is nothrow-callable with _Args
};

_EXPORT_STD template <class _Callable, class... _Args>
constexpr bool is_nothrow_invocable_v = _Select_invoke_traits<_Callable, _Args...>::_Is_nothrow_invocable::value;

_EXPORT_STD template <class _Rx, class _Callable, class... _Args>
struct is_invocable_r : _Is_invocable_r_<_Rx, _Callable, _Args...> {
    // determines whether _Callable is callable with _Args and return type _Rx
};

_EXPORT_STD template <class _Rx, class _Callable, class... _Args>
constexpr bool is_invocable_r_v = _Is_invocable_r_<_Rx, _Callable, _Args...>::value;

_EXPORT_STD template <class _Rx, class _Callable, class... _Args>
struct is_nothrow_invocable_r : _Select_invoke_traits<_Callable, _Args...>::template _Is_nothrow_invocable_r<_Rx> {
    // determines whether _Callable is nothrow-callable with _Args and return type _Rx
};

_EXPORT_STD template <class _Rx, class _Callable, class... _Args>
constexpr bool is_nothrow_invocable_r_v =
    _Select_invoke_traits<_Callable, _Args...>::template _Is_nothrow_invocable_r<_Rx>::value;
#endif // _HAS_CXX17

#if _HAS_CXX20
#ifndef __clang__ // TRANSITION, LLVM-48860
_EXPORT_STD template <class _Ty1, class _Ty2>
struct is_layout_compatible : bool_constant<__is_layout_compatible(_Ty1, _Ty2)> {};

_EXPORT_STD template <class _Ty1, class _Ty2>
constexpr bool is_layout_compatible_v = __is_layout_compatible(_Ty1, _Ty2);

_EXPORT_STD template <class _Base, class _Derived>
struct is_pointer_interconvertible_base_of : bool_constant<__is_pointer_interconvertible_base_of(_Base, _Derived)> {};

_EXPORT_STD template <class _Base, class _Derived>
constexpr bool is_pointer_interconvertible_base_of_v = __is_pointer_interconvertible_base_of(_Base, _Derived);

_EXPORT_STD template <class _ClassTy, class _MemberTy>
_NODISCARD constexpr bool is_pointer_interconvertible_with_class(_MemberTy _ClassTy::*_Pm) noexcept {
    return __is_pointer_interconvertible_with_class(_ClassTy, _Pm);
}

_EXPORT_STD template <class _ClassTy1, class _ClassTy2, class _MemberTy1, class _MemberTy2>
_NODISCARD constexpr bool is_corresponding_member(_MemberTy1 _ClassTy1::*_Pm1, _MemberTy2 _ClassTy2::*_Pm2) noexcept {
    return __is_corresponding_member(_ClassTy1, _ClassTy2, _Pm1, _Pm2);
}
#endif // ^^^ no workaround ^^^
#endif // _HAS_CXX20

template <class _Ty>
struct _Function_args {}; // determine whether _Ty is a function

#define _FUNCTION_ARGS(CALL_OPT, CV_OPT, REF_OPT, NOEXCEPT_OPT)                                           \
    template <class _Ret, class... _Types>                                                                \
    struct _Function_args<_Ret CALL_OPT(_Types...) CV_OPT REF_OPT NOEXCEPT_OPT> : _Arg_types<_Types...> { \
        using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = _Ret;                                 \
    };

_NON_MEMBER_CALL_CV_REF_NOEXCEPT(_FUNCTION_ARGS)
#undef _FUNCTION_ARGS

#define _FUNCTION_ARGS_ELLIPSIS(CV_REF_NOEXCEPT_OPT)                                                            \
    template <class _Ret, class... _Types>                                                                      \
    struct _Function_args<_Ret(_Types..., ...) CV_REF_NOEXCEPT_OPT> { /* no calling conventions for ellipsis */ \
        using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = _Ret;                                       \
    };

_CLASS_DEFINE_CV_REF_NOEXCEPT(_FUNCTION_ARGS_ELLIPSIS)
#undef _FUNCTION_ARGS_ELLIPSIS

template <class _Ty, class = void>
struct _Weak_result_type {}; // default definition

_STL_DISABLE_DEPRECATED_WARNING
template <class _Ty>
struct _Weak_result_type<_Ty, void_t<typename _Ty::result_type>> { // defined if _Ty::result_type exists
    using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = typename _Ty::result_type;
};
_STL_RESTORE_DEPRECATED_WARNING

template <class _Ty, class = void>
struct _Weak_argument_type : _Weak_result_type<_Ty> {}; // default definition

_STL_DISABLE_DEPRECATED_WARNING
template <class _Ty>
struct _Weak_argument_type<_Ty, void_t<typename _Ty::argument_type>> : _Weak_result_type<_Ty> {
    // defined if _Ty::argument_type exists
    using _ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = typename _Ty::argument_type;
};
_STL_RESTORE_DEPRECATED_WARNING

template <class _Ty, class = void>
struct _Weak_binary_args : _Weak_argument_type<_Ty> {}; // default definition

_STL_DISABLE_DEPRECATED_WARNING
template <class _Ty>
struct _Weak_binary_args<_Ty, void_t<typename _Ty::first_argument_type,
                                  typename _Ty::second_argument_type>>
    : _Weak_argument_type<_Ty> { // defined if both types exist
    using _FIRST_ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS  = typename _Ty::first_argument_type;
    using _SECOND_ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = typename _Ty::second_argument_type;
};
_STL_RESTORE_DEPRECATED_WARNING

template <class _Ty>
using _Weak_types = conditional_t<is_function_v<remove_pointer_t<_Ty>>, _Function_args<remove_pointer_t<_Ty>>,
    conditional_t<is_member_function_pointer_v<_Ty>, _Is_memfunptr<remove_cv_t<_Ty>>, _Weak_binary_args<_Ty>>>;

template <class _Ty>
void _Refwrap_ctor_fun(_Identity_t<_Ty&>) noexcept; // not defined
template <class _Ty>
void _Refwrap_ctor_fun(_Identity_t<_Ty&&>) = delete;

template <class _Ty, class _Uty, class = void>
struct _Refwrap_has_ctor_from : false_type {};

template <class _Ty, class _Uty>
struct _Refwrap_has_ctor_from<_Ty, _Uty, void_t<decltype(_STD _Refwrap_ctor_fun<_Ty>(_STD declval<_Uty>()))>>
    : true_type {}; // _STD _Refwrap_ctor_fun is qualified: avoid ADL, handle incomplete types

_EXPORT_STD template <class _Ty>
class reference_wrapper
#if !_HAS_CXX20
    : public _Weak_types<_Ty>
#endif // !_HAS_CXX20
{
public:
    static_assert(is_object_v<_Ty> || is_function_v<_Ty>,
        "reference_wrapper<T> requires T to be an object type or a function type.");

    using type = _Ty;

    template <class _Uty, enable_if_t<conjunction_v<negation<is_same<_Remove_cvref_t<_Uty>, reference_wrapper>>,
                                          _Refwrap_has_ctor_from<_Ty, _Uty>>,
                              int> = 0>
    _CONSTEXPR20 reference_wrapper(_Uty&& _Val) noexcept(
        noexcept(_STD _Refwrap_ctor_fun<_Ty>(_STD declval<_Uty>()))) { // qualified: avoid ADL, handle incomplete types
        _Ty& _Ref = static_cast<_Uty&&>(_Val);
        _Ptr      = _STD addressof(_Ref);
    }

    _CONSTEXPR20 operator _Ty&() const noexcept {
        return *_Ptr;
    }

    _NODISCARD _CONSTEXPR20 _Ty& get() const noexcept {
        return *_Ptr;
    }

private:
    _Ty* _Ptr{};

public:
    template <class... _Types>
    _CONSTEXPR20 auto operator()(_Types&&... _Args) const
        noexcept(noexcept(_STD invoke(*_Ptr, static_cast<_Types&&>(_Args)...)))
            -> decltype(_STD invoke(*_Ptr, static_cast<_Types&&>(_Args)...)) {
        return _STD invoke(*_Ptr, static_cast<_Types&&>(_Args)...);
    }
};

#if _HAS_CXX17
template <class _Ty>
reference_wrapper(_Ty&) -> reference_wrapper<_Ty>;
#endif // _HAS_CXX17

_EXPORT_STD template <class _Ty>
_NODISCARD _CONSTEXPR20 reference_wrapper<_Ty> ref(_Ty& _Val) noexcept {
    return reference_wrapper<_Ty>(_Val);
}

_EXPORT_STD template <class _Ty>
void ref(const _Ty&&) = delete;

_EXPORT_STD template <class _Ty>
_NODISCARD _CONSTEXPR20 reference_wrapper<_Ty> ref(reference_wrapper<_Ty> _Val) noexcept {
    return _Val;
}

_EXPORT_STD template <class _Ty>
_NODISCARD _CONSTEXPR20 reference_wrapper<const _Ty> cref(const _Ty& _Val) noexcept {
    return reference_wrapper<const _Ty>(_Val);
}

_EXPORT_STD template <class _Ty>
void cref(const _Ty&&) = delete;

_EXPORT_STD template <class _Ty>
_NODISCARD _CONSTEXPR20 reference_wrapper<const _Ty> cref(reference_wrapper<_Ty> _Val) noexcept {
    return _Val;
}

#if _HAS_CXX20
_EXPORT_STD template <class _Ty>
struct unwrap_reference {
    using type = _Ty;
};
template <class _Ty>
struct unwrap_reference<reference_wrapper<_Ty>> {
    using type = _Ty&;
};
_EXPORT_STD template <class _Ty>
using unwrap_reference_t = unwrap_reference<_Ty>::type;

_EXPORT_STD template <class _Ty>
using unwrap_ref_decay_t = unwrap_reference_t<decay_t<_Ty>>;
_EXPORT_STD template <class _Ty>
struct unwrap_ref_decay {
    using type = unwrap_ref_decay_t<_Ty>;
};
#endif // _HAS_CXX20

template <class _Ty>
struct _Is_swappable;

template <class _Ty>
struct _Is_nothrow_swappable;

#if _HAS_CXX17
_EXPORT_STD template <class _Ty, enable_if_t<is_move_constructible_v<_Ty> && is_move_assignable_v<_Ty>, int> = 0>
#else // ^^^ _HAS_CXX17 / !_HAS_CXX17 vvv
template <class _Ty, int _Enabled = 0>
#endif // ^^^ !_HAS_CXX17 ^^^
_CONSTEXPR20 void swap(_Ty&, _Ty&) noexcept(is_nothrow_move_constructible_v<_Ty> && is_nothrow_move_assignable_v<_Ty>);

_EXPORT_STD template <class _Ty, size_t _Size, enable_if_t<_Is_swappable<_Ty>::value, int> = 0>
_CONSTEXPR20 void swap(_Ty (&)[_Size], _Ty (&)[_Size]) noexcept(_Is_nothrow_swappable<_Ty>::value);

template <class _Ty1, class _Ty2, class = void>
struct _Swappable_with_helper : false_type {}; // swap(declval<_Ty1>(), declval<_Ty2>()) is not valid

template <class _Ty1, class _Ty2>
struct _Swappable_with_helper<_Ty1, _Ty2, void_t<decltype(swap(_STD declval<_Ty1>(), _STD declval<_Ty2>()))>>
    : true_type {}; // swap(declval<_Ty1>(), declval<_Ty2>()) is valid

template <class _Ty1, class _Ty2>
struct _Is_swappable_with
    : bool_constant<conjunction_v<_Swappable_with_helper<_Ty1, _Ty2>, _Swappable_with_helper<_Ty2, _Ty1>>> {
    // Determine if expressions with type and value category _Ty1 and _Ty2 can be swapped (and vice versa)
};

template <class _Ty>
struct _Is_swappable : _Is_swappable_with<add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<_Ty>>::type {
    // Determine if _Ty lvalues satisfy is_swappable_with
};

template <class _Ty1, class _Ty2>
struct _Swap_cannot_throw : bool_constant<noexcept(swap(_STD declval<_Ty1>(), _STD declval<_Ty2>()))
                                          && noexcept(swap(_STD declval<_Ty2>(), _STD declval<_Ty1>()))> {
    // Determine if expressions with type and value category _Ty1 and _Ty2
    // (presumed to satisfy is_swappable_with) can be swapped without emitting exceptions
};

template <class _Ty1, class _Ty2>
struct _Is_nothrow_swappable_with
    : bool_constant<conjunction_v<_Is_swappable_with<_Ty1, _Ty2>, _Swap_cannot_throw<_Ty1, _Ty2>>> {
    // Determine if expressions with type and value category _Ty1 and _Ty2
    // satisfy is_swappable_with, and can be swapped without emitting exceptions
};

template <class _Ty>
struct _Is_nothrow_swappable
    : _Is_nothrow_swappable_with<add_lvalue_reference_t<_Ty>, add_lvalue_reference_t<_Ty>>::type {
    // Determine if _Ty lvalues satisfy is_nothrow_swappable_with
};

#if _HAS_CXX17
_EXPORT_STD template <class _Ty1, class _Ty2>
struct is_swappable_with : _Is_swappable_with<_Ty1, _Ty2>::type {
    // Determine if expressions with type and value category _Ty1 and _Ty2
    // can be swapped (and vice versa)
};

_EXPORT_STD template <class _Ty1, class _Ty2>
constexpr bool is_swappable_with_v =
    conjunction_v<_Swappable_with_helper<_Ty1, _Ty2>, _Swappable_with_helper<_Ty2, _Ty1>>;

_EXPORT_STD template <class _Ty>
struct is_swappable : _Is_swappable<_Ty>::type {}; // Determine if _Ty lvalues satisfy is_swappable_with

_EXPORT_STD template <class _Ty>
constexpr bool is_swappable_v = _Is_swappable<_Ty>::value;

_EXPORT_STD template <class _Ty1, class _Ty2>
struct is_nothrow_swappable_with : _Is_nothrow_swappable_with<_Ty1, _Ty2>::type {
    // Determine if expressions with type and value category _Ty1 and _Ty2
    // satisfy is_swappable_with, and can be swapped without emitting exceptions
};

_EXPORT_STD template <class _Ty1, class _Ty2>
constexpr bool is_nothrow_swappable_with_v = _Is_nothrow_swappable_with<_Ty1, _Ty2>::value;

_EXPORT_STD template <class _Ty>
struct is_nothrow_swappable : _Is_nothrow_swappable<_Ty>::type {
    // Determine if _Ty lvalues satisfy is_nothrow_swappable_with
};

_EXPORT_STD template <class _Ty>
constexpr bool is_nothrow_swappable_v = _Is_nothrow_swappable<_Ty>::value;
#endif // _HAS_CXX17

namespace _Has_ADL_swap_detail {
#if defined(__clang__) || defined(__EDG__) // TRANSITION, VSO-1681199
    void swap() = delete; // Block unqualified name lookup
#else // ^^^ no workaround / workaround vvv
    void swap();
#endif // ^^^ workaround ^^^

    template <class, class = void>
    struct _Has_ADL_swap : false_type {};
    template <class _Ty>
    struct _Has_ADL_swap<_Ty, void_t<decltype(swap(_STD declval<_Ty&>(), _STD declval<_Ty&>()))>> : true_type {};
} // namespace _Has_ADL_swap_detail
using _Has_ADL_swap_detail::_Has_ADL_swap;

template <class _Ty>
constexpr bool _Is_trivially_swappable_v = conjunction_v<is_trivially_destructible<_Ty>,
    is_trivially_move_constructible<_Ty>, is_trivially_move_assignable<_Ty>, negation<_Has_ADL_swap<_Ty>>>;

#ifdef __cpp_lib_byte
template <>
inline constexpr bool _Is_trivially_swappable_v<byte> = true;
#endif // defined(__cpp_lib_byte)

template <class _Ty>
struct _Is_trivially_swappable : bool_constant<_Is_trivially_swappable_v<_Ty>> {
    // true_type if and only if it is valid to swap two _Ty lvalues by exchanging object representations.
};

#if _HAS_CXX20
_EXPORT_STD template <class _From, class _To>
concept convertible_to =
#if !defined(__clang__) && !defined(__EDG__) // TRANSITION, DevCom-1627396
    is_convertible_v<_From, _To>
#else // ^^^ workaround / no workaround vvv
    __is_convertible_to(_From, _To)
#endif // ^^^ no workaround ^^^
    && requires { static_cast<_To>(_STD declval<_From>()); };

template <class _RefWrap, class _Ty, class _RefWrapQ, class _TyQ>
concept _Ref_wrap_common_reference_exists_with = _Is_specialization_v<_RefWrap, reference_wrapper> && requires {
    typename common_reference_t<typename _RefWrap::type&, _TyQ>;
} && convertible_to<_RefWrapQ, common_reference_t<typename _RefWrap::type&, _TyQ>>;

template <class _RefWrap, class _Ty, template <class> class _RefWrapQual, template <class> class _TyQual>
    requires (_Ref_wrap_common_reference_exists_with<_RefWrap, _Ty, _RefWrapQual<_RefWrap>, _TyQual<_Ty>>
              && !_Ref_wrap_common_reference_exists_with<_Ty, _RefWrap, _TyQual<_Ty>, _RefWrapQual<_RefWrap>>)
struct basic_common_reference<_RefWrap, _Ty, _RefWrapQual, _TyQual> {
    using type = common_reference_t<typename _RefWrap::type&, _TyQual<_Ty>>;
};

template <class _Ty, class _RefWrap, template <class> class _TyQual, template <class> class _RefWrapQual>
    requires (_Ref_wrap_common_reference_exists_with<_RefWrap, _Ty, _RefWrapQual<_RefWrap>, _TyQual<_Ty>>
              && !_Ref_wrap_common_reference_exists_with<_Ty, _RefWrap, _TyQual<_Ty>, _RefWrapQual<_RefWrap>>)
struct basic_common_reference<_Ty, _RefWrap, _TyQual, _RefWrapQual> {
    using type = common_reference_t<typename _RefWrap::type&, _TyQual<_Ty>>;
};
#endif // _HAS_CXX20

#define _BITMASK_OPS(_MAYBE_EXPORT, _BITMASK)                                                         \
    _MAYBE_EXPORT _NODISCARD constexpr _BITMASK operator&(_BITMASK _Left, _BITMASK _Right) noexcept { \
        using _IntTy = _STD underlying_type_t<_BITMASK>;                                              \
        return static_cast<_BITMASK>(static_cast<_IntTy>(_Left) & static_cast<_IntTy>(_Right));       \
    }                                                                                                 \
                                                                                                      \
    _MAYBE_EXPORT _NODISCARD constexpr _BITMASK operator|(_BITMASK _Left, _BITMASK _Right) noexcept { \
        using _IntTy = _STD underlying_type_t<_BITMASK>;                                              \
        return static_cast<_BITMASK>(static_cast<_IntTy>(_Left) | static_cast<_IntTy>(_Right));       \
    }                                                                                                 \
                                                                                                      \
    _MAYBE_EXPORT _NODISCARD constexpr _BITMASK operator^(_BITMASK _Left, _BITMASK _Right) noexcept { \
        using _IntTy = _STD underlying_type_t<_BITMASK>;                                              \
        return static_cast<_BITMASK>(static_cast<_IntTy>(_Left) ^ static_cast<_IntTy>(_Right));       \
    }                                                                                                 \
                                                                                                      \
    _MAYBE_EXPORT constexpr _BITMASK& operator&=(_BITMASK& _Left, _BITMASK _Right) noexcept {         \
        return _Left = _Left & _Right;                                                                \
    }                                                                                                 \
                                                                                                      \
    _MAYBE_EXPORT constexpr _BITMASK& operator|=(_BITMASK& _Left, _BITMASK _Right) noexcept {         \
        return _Left = _Left | _Right;                                                                \
    }                                                                                                 \
                                                                                                      \
    _MAYBE_EXPORT constexpr _BITMASK& operator^=(_BITMASK& _Left, _BITMASK _Right) noexcept {         \
        return _Left = _Left ^ _Right;                                                                \
    }                                                                                                 \
                                                                                                      \
    _MAYBE_EXPORT _NODISCARD constexpr _BITMASK operator~(_BITMASK _Left) noexcept {                  \
        using _IntTy = _STD underlying_type_t<_BITMASK>;                                              \
        return static_cast<_BITMASK>(~static_cast<_IntTy>(_Left));                                    \
    }

template <class _Bitmask>
_NODISCARD constexpr bool _Bitmask_includes_any(_Bitmask _Left, _Bitmask _Elements) noexcept {
    return (_Left & _Elements) != _Bitmask{};
}

template <class _Bitmask>
_NODISCARD constexpr bool _Bitmask_includes_all(_Bitmask _Left, _Bitmask _Elements) noexcept {
    return (_Left & _Elements) == _Elements;
}

// These FNV-1a utility functions are extremely performance sensitive,
// check examples like that in VSO-653642 before making changes.
#if defined(_WIN64)
_INLINE_VAR constexpr size_t _FNV_offset_basis = 14695981039346656037ULL;
_INLINE_VAR constexpr size_t _FNV_prime        = 1099511628211ULL;
#else // ^^^ defined(_WIN64) / !defined(_WIN64) vvv
_INLINE_VAR constexpr size_t _FNV_offset_basis = 2166136261U;
_INLINE_VAR constexpr size_t _FNV_prime        = 16777619U;
#endif // ^^^ !defined(_WIN64) ^^^

_NODISCARD inline size_t _Fnv1a_append_bytes(size_t _Val, const unsigned char* const _First,
    const size_t _Count) noexcept { // accumulate range [_First, _First + _Count) into partial FNV-1a hash _Val
    for (size_t _Idx = 0; _Idx < _Count; ++_Idx) {
        _Val ^= static_cast<size_t>(_First[_Idx]);
        _Val *= _FNV_prime;
    }

    return _Val;
}

template <class _Ty>
_NODISCARD size_t _Fnv1a_append_range(const size_t _Val, const _Ty* const _First,
    const _Ty* const _Last) noexcept { // accumulate range [_First, _Last) into partial FNV-1a hash _Val
    static_assert(is_trivial_v<_Ty>, "Only trivial types can be directly hashed.");
    const auto _Firstb = reinterpret_cast<const unsigned char*>(_First);
    const auto _Lastb  = reinterpret_cast<const unsigned char*>(_Last);
    return _Fnv1a_append_bytes(_Val, _Firstb, static_cast<size_t>(_Lastb - _Firstb));
}

template <class _Kty>
_NODISCARD size_t _Fnv1a_append_value(
    const size_t _Val, const _Kty& _Keyval) noexcept { // accumulate _Keyval into partial FNV-1a hash _Val
    static_assert(is_trivial_v<_Kty>, "Only trivial types can be directly hashed.");
    return _Fnv1a_append_bytes(_Val, &reinterpret_cast<const unsigned char&>(_Keyval), sizeof(_Kty));
}

template <class _Kty>
_NODISCARD size_t _Hash_representation(const _Kty& _Keyval) noexcept { // bitwise hashes the representation of a key
    return _Fnv1a_append_value(_FNV_offset_basis, _Keyval);
}

template <class _Kty>
_NODISCARD size_t _Hash_array_representation(
    const _Kty* const _First, const size_t _Count) noexcept { // bitwise hashes the representation of an array
    static_assert(is_trivial_v<_Kty>, "Only trivial types can be directly hashed.");
    return _Fnv1a_append_bytes(
        _FNV_offset_basis, reinterpret_cast<const unsigned char*>(_First), _Count * sizeof(_Kty));
}

_EXPORT_STD template <class _Kty>
struct hash;

template <class _Kty, bool _Enabled>
struct _Conditionally_enabled_hash { // conditionally enabled hash base
    using _ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = _Kty;
    using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS   = size_t;

    _NODISCARD _STATIC_CALL_OPERATOR size_t operator()(const _Kty& _Keyval) _CONST_CALL_OPERATOR
        noexcept(noexcept(hash<_Kty>::_Do_hash(_Keyval))) /* strengthened */ {
        return hash<_Kty>::_Do_hash(_Keyval);
    }
};

template <class _Kty>
struct _Conditionally_enabled_hash<_Kty, false> { // conditionally disabled hash base
    _Conditionally_enabled_hash()                                              = delete;
    _Conditionally_enabled_hash(const _Conditionally_enabled_hash&)            = delete;
    _Conditionally_enabled_hash(_Conditionally_enabled_hash&&)                 = delete;
    _Conditionally_enabled_hash& operator=(const _Conditionally_enabled_hash&) = delete;
    _Conditionally_enabled_hash& operator=(_Conditionally_enabled_hash&&)      = delete;
};

_EXPORT_STD template <class _Kty>
struct hash : _Conditionally_enabled_hash<_Kty, !is_const_v<_Kty> && !is_volatile_v<_Kty>
                                                    && (is_enum_v<_Kty> || is_integral_v<_Kty> || is_pointer_v<_Kty>)> {
    // hash functor primary template (handles enums, integrals, and pointers)
    static size_t _Do_hash(const _Kty& _Keyval) noexcept {
        return _Hash_representation(_Keyval);
    }
};

template <>
struct hash<float> {
    using _ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = float;
    using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS   = size_t;
    _NODISCARD _STATIC_CALL_OPERATOR size_t operator()(const float _Keyval) _CONST_CALL_OPERATOR noexcept {
        return _Hash_representation(_Keyval == 0.0F ? 0.0F : _Keyval); // map -0 to 0
    }
};

template <>
struct hash<double> {
    using _ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = double;
    using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS   = size_t;
    _NODISCARD _STATIC_CALL_OPERATOR size_t operator()(const double _Keyval) _CONST_CALL_OPERATOR noexcept {
        return _Hash_representation(_Keyval == 0.0 ? 0.0 : _Keyval); // map -0 to 0
    }
};

template <>
struct hash<long double> {
    using _ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = long double;
    using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS   = size_t;
    _NODISCARD _STATIC_CALL_OPERATOR size_t operator()(const long double _Keyval) _CONST_CALL_OPERATOR noexcept {
        return _Hash_representation(_Keyval == 0.0L ? 0.0L : _Keyval); // map -0 to 0
    }
};

template <>
struct hash<nullptr_t> {
    using _ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = nullptr_t;
    using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS   = size_t;
    _NODISCARD _STATIC_CALL_OPERATOR size_t operator()(nullptr_t) _CONST_CALL_OPERATOR noexcept {
        void* _Null{};
        return _Hash_representation(_Null);
    }
};

template <class _Kty, class = void>
struct _Is_nothrow_hashable : false_type {}; // tests if std::hash can hash _Kty with noexcept

template <class _Kty>
struct _Is_nothrow_hashable<_Kty, void_t<decltype(hash<_Kty>{}(_STD declval<const _Kty&>()))>>
    : bool_constant<noexcept(hash<_Kty>{}(_STD declval<const _Kty&>()))> {};

_EXPORT_STD template <class _Ty = void>
struct less {
    using _FIRST_ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS  = _Ty;
    using _SECOND_ARGUMENT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS = _Ty;
    using _RESULT_TYPE_NAME _CXX17_DEPRECATE_ADAPTOR_TYPEDEFS          = bool;

    _NODISCARD constexpr bool operator()(const _Ty& _Left, const _Ty& _Right) const
        noexcept(noexcept(_STD _Fake_copy_init<bool>(_Left < _Right))) /* strengthened */ {
        return _Left < _Right;
    }
};

template <>
struct less<void> {
    template <class _Ty1, class _Ty2>
    _NODISCARD constexpr auto operator()(_Ty1&& _Left, _Ty2&& _Right) const
        noexcept(noexcept(static_cast<_Ty1&&>(_Left) < static_cast<_Ty2&&>(_Right))) // strengthened
        -> decltype(static_cast<_Ty1&&>(_Left) < static_cast<_Ty2&&>(_Right)) {
        return static_cast<_Ty1&&>(_Left) < static_cast<_Ty2&&>(_Right);
    }

    using is_transparent = int;
};

// vvvvvvvvvv DERIVED FROM corecrt_internal_fltintrn.h vvvvvvvvvv

template <class _FloatingType>
struct _Floating_type_traits;

template <>
struct _Floating_type_traits<float> {
    static constexpr int32_t _Mantissa_bits           = 24; // FLT_MANT_DIG
    static constexpr int32_t _Exponent_bits           = 8; // sizeof(float) * CHAR_BIT - FLT_MANT_DIG
    static constexpr int32_t _Maximum_binary_exponent = 127; // FLT_MAX_EXP - 1
    static constexpr int32_t _Minimum_binary_exponent = -126; // FLT_MIN_EXP - 1
    static constexpr int32_t _Exponent_bias           = 127;
    static constexpr int32_t _Sign_shift              = 31; // _Exponent_bits + _Mantissa_bits - 1
    static constexpr int32_t _Exponent_shift          = 23; // _Mantissa_bits - 1

    using _Uint_type = uint32_t;

    static constexpr uint32_t _Exponent_mask             = 0x000000FFu; // (1u << _Exponent_bits) - 1
    static constexpr uint32_t _Normal_mantissa_mask      = 0x00FFFFFFu; // (1u << _Mantissa_bits) - 1
    static constexpr uint32_t _Denormal_mantissa_mask    = 0x007FFFFFu; // (1u << (_Mantissa_bits - 1)) - 1
    static constexpr uint32_t _Special_nan_mantissa_mask = 0x00400000u; // 1u << (_Mantissa_bits - 2)
    static constexpr uint32_t _Shifted_sign_mask         = 0x80000000u; // 1u << _Sign_shift
    static constexpr uint32_t _Shifted_exponent_mask     = 0x7F800000u; // _Exponent_mask << _Exponent_shift
};

template <>
struct _Floating_type_traits<double> {
    static constexpr int32_t _Mantissa_bits           = 53; // DBL_MANT_DIG
    static constexpr int32_t _Exponent_bits           = 11; // sizeof(double) * CHAR_BIT - DBL_MANT_DIG
    static constexpr int32_t _Maximum_binary_exponent = 1023; // DBL_MAX_EXP - 1
    static constexpr int32_t _Minimum_binary_exponent = -1022; // DBL_MIN_EXP - 1
    static constexpr int32_t _Exponent_bias           = 1023;
    static constexpr int32_t _Sign_shift              = 63; // _Exponent_bits + _Mantissa_bits - 1
    static constexpr int32_t _Exponent_shift          = 52; // _Mantissa_bits - 1

    using _Uint_type = uint64_t;

    static constexpr uint64_t _Exponent_mask             = 0x00000000000007FFu; // (1ULL << _Exponent_bits) - 1
    static constexpr uint64_t _Normal_mantissa_mask      = 0x001FFFFFFFFFFFFFu; // (1ULL << _Mantissa_bits) - 1
    static constexpr uint64_t _Denormal_mantissa_mask    = 0x000FFFFFFFFFFFFFu; // (1ULL << (_Mantissa_bits - 1)) - 1
    static constexpr uint64_t _Special_nan_mantissa_mask = 0x0008000000000000u; // 1ULL << (_Mantissa_bits - 2)
    static constexpr uint64_t _Shifted_sign_mask         = 0x8000000000000000u; // 1ULL << _Sign_shift
    static constexpr uint64_t _Shifted_exponent_mask     = 0x7FF0000000000000u; // _Exponent_mask << _Exponent_shift
};

template <>
struct _Floating_type_traits<long double> : _Floating_type_traits<double> {};

// ^^^^^^^^^^ DERIVED FROM corecrt_internal_fltintrn.h ^^^^^^^^^^

template <class _To, class _From,
    enable_if_t<conjunction_v<bool_constant<sizeof(_To) == sizeof(_From)>, is_trivially_copyable<_To>,
                    is_trivially_copyable<_From>>,
        int> = 0>
_NODISCARD constexpr _To _Bit_cast(const _From& _Val) noexcept {
    return __builtin_bit_cast(_To, _Val);
}

template <bool _IsConst, class _Ty>
using _Maybe_const = conditional_t<_IsConst, const _Ty, _Ty>;

#if _HAS_TR1_NAMESPACE
_STL_DISABLE_DEPRECATED_WARNING
namespace _DEPRECATE_TR1_NAMESPACE tr1 {
    using _STD add_const;
    using _STD add_cv;
    using _STD add_pointer;
    using _STD add_volatile;
    using _STD aligned_storage;
    using _STD alignment_of;
    using _STD conditional;
    using _STD decay;
    using _STD enable_if;
    using _STD extent;
    using _STD false_type;
    using _STD has_virtual_destructor;
    using _STD integral_constant;
    using _STD is_abstract;
    using _STD is_arithmetic;
    using _STD is_array;
    using _STD is_base_of;
    using _STD is_class;
    using _STD is_compound;
    using _STD is_const;
    using _STD is_convertible;
    using _STD is_empty;
    using _STD is_enum;
    using _STD is_floating_point;
    using _STD is_function;
    using _STD is_fundamental;
    using _STD is_integral;
    using _STD is_member_function_pointer;
    using _STD is_member_object_pointer;
    using _STD is_member_pointer;
    using _STD is_object;
    using _STD is_pod;
    using _STD is_pointer;
    using _STD is_polymorphic;
    using _STD is_reference;
    using _STD is_same;
    using _STD is_scalar;
    using _STD is_signed;
    using _STD is_union;
    using _STD is_unsigned;
    using _STD is_void;
    using _STD is_volatile;
    using _STD make_signed;
    using _STD make_unsigned;
    using _STD rank;
    using _STD remove_all_extents;
    using _STD remove_const;
    using _STD remove_cv;
    using _STD remove_extent;
    using _STD remove_pointer;
    using _STD remove_reference;
    using _STD remove_volatile;
    using _STD true_type;
    using _STD cref;
    using _STD ref;
    using _STD reference_wrapper;
#if _HAS_DEPRECATED_RESULT_OF
    using _STD result_of;
#endif // _HAS_DEPRECATED_RESULT_OF
    using _STD hash;
} // namespace _DEPRECATE_TR1_NAMESPACE tr1
_STL_RESTORE_DEPRECATED_WARNING
#endif // _HAS_TR1_NAMESPACE

_STD_END

// TRANSITION, non-_Ugly attribute tokens
#pragma pop_macro("known_semantics")
#pragma pop_macro("intrinsic")
#pragma pop_macro("msvc")

#pragma pop_macro("new")
_STL_RESTORE_CLANG_WARNINGS
#pragma warning(pop)
#pragma pack(pop)

#endif // _STL_COMPILER_PREPROCESSOR
#endif // _TYPE_TRAITS_