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xutility
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// xutility internal header
// Copyright (c) Microsoft Corporation.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#pragma once
#ifndef _XUTILITY_
#define _XUTILITY_
#include <yvals.h>
#if _STL_COMPILER_PREPROCESSOR
#include <__msvc_iter_core.hpp>
#include <climits>
#include <cstdlib>
#include <cstring>
#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
#if defined(_CRTBLD) && defined(CRTDLL2)
// TRANSITION, ABI: The vector algorithms are compiled into the import lib, so we disable their usage when building
// the DLL. (We could additionally link them into the DLL - not as exports, just for internal usage - but we
// haven't chosen to do that yet.) When we can break ABI and export the vector algorithms from the DLL,
// this preprocessor case should be removed.
#ifndef _USE_STD_VECTOR_ALGORITHMS
#define _USE_STD_VECTOR_ALGORITHMS 0
#elif _USE_STD_VECTOR_ALGORITHMS
#error Vector algorithms are not supported when building msvcp140.dll, but _USE_STD_VECTOR_ALGORITHMS is set.
#endif // _USE_STD_VECTOR_ALGORITHMS
#elif (defined(_M_IX86) || defined(_M_X64)) && !defined(_M_CEE_PURE) && !defined(_M_HYBRID) && !defined(_M_ARM64EC)
#ifndef _USE_STD_VECTOR_ALGORITHMS
#define _USE_STD_VECTOR_ALGORITHMS 1
#endif // _USE_STD_VECTOR_ALGORITHMS
#else // ^^^ arch supports vector algorithms / no support for vector algorithms vvv
#ifndef _USE_STD_VECTOR_ALGORITHMS
#define _USE_STD_VECTOR_ALGORITHMS 0
#elif _USE_STD_VECTOR_ALGORITHMS
#error Vector algorithms are not supported on this architecture, but _USE_STD_VECTOR_ALGORITHMS is set.
#endif // _USE_STD_VECTOR_ALGORITHMS
#endif // ^^^ no support for vector algorithms ^^^
#ifdef __CUDACC__
#define _CONSTEXPR_BIT_CAST inline
#else // ^^^ workaround ^^^ / vvv no workaround vvv
#define _CONSTEXPR_BIT_CAST constexpr
#endif // ^^^ no workaround ^^^
#if _USE_STD_VECTOR_ALGORITHMS
_EXTERN_C
// The "noalias" attribute tells the compiler optimizer that pointers going into these hand-vectorized algorithms
// won't be stored beyond the lifetime of the function, and that the function will only reference arrays denoted by
// those pointers. The optimizer also assumes in that case that a pointer parameter is not returned to the caller via
// the return value, so functions using "noalias" must usually return void. This attribute is valuable because these
// functions are in native code objects that the compiler cannot analyze. In the absence of the noalias attribute, the
// compiler has to assume that the denoted arrays are "globally address taken", and that any later calls to
// unanalyzable routines may modify those arrays.
__declspec(noalias) void __cdecl __std_reverse_trivially_swappable_1(void* _First, void* _Last) noexcept;
__declspec(noalias) void __cdecl __std_reverse_trivially_swappable_2(void* _First, void* _Last) noexcept;
__declspec(noalias) void __cdecl __std_reverse_trivially_swappable_4(void* _First, void* _Last) noexcept;
__declspec(noalias) void __cdecl __std_reverse_trivially_swappable_8(void* _First, void* _Last) noexcept;
__declspec(noalias) void __cdecl __std_swap_ranges_trivially_swappable_noalias(
void* _First1, void* _Last1, void* _First2) noexcept;
__declspec(noalias) size_t
__stdcall __std_count_trivial_1(const void* _First, const void* _Last, uint8_t _Val) noexcept;
__declspec(noalias) size_t
__stdcall __std_count_trivial_2(const void* _First, const void* _Last, uint16_t _Val) noexcept;
__declspec(noalias) size_t
__stdcall __std_count_trivial_4(const void* _First, const void* _Last, uint32_t _Val) noexcept;
__declspec(noalias) size_t
__stdcall __std_count_trivial_8(const void* _First, const void* _Last, uint64_t _Val) noexcept;
const void* __stdcall __std_find_trivial_1(const void* _First, const void* _Last, uint8_t _Val) noexcept;
const void* __stdcall __std_find_trivial_2(const void* _First, const void* _Last, uint16_t _Val) noexcept;
const void* __stdcall __std_find_trivial_4(const void* _First, const void* _Last, uint32_t _Val) noexcept;
const void* __stdcall __std_find_trivial_8(const void* _First, const void* _Last, uint64_t _Val) noexcept;
const void* __stdcall __std_find_trivial_unsized_1(const void* _First, uint8_t _Val) noexcept;
const void* __stdcall __std_find_trivial_unsized_2(const void* _First, uint16_t _Val) noexcept;
const void* __stdcall __std_find_trivial_unsized_4(const void* _First, uint32_t _Val) noexcept;
const void* __stdcall __std_find_trivial_unsized_8(const void* _First, uint64_t _Val) noexcept;
_END_EXTERN_C
template <class _Ty, class _TVal>
__declspec(noalias) size_t __std_count_trivial(_Ty* _First, _Ty* _Last, const _TVal _Val) noexcept {
if constexpr (_STD is_pointer_v<_TVal> || _STD is_null_pointer_v<_TVal>) {
return __std_count_trivial(_First, _Last, reinterpret_cast<uintptr_t>(_Val));
} else if constexpr (sizeof(_Ty) == 1) {
return __std_count_trivial_1(_First, _Last, static_cast<uint8_t>(_Val));
} else if constexpr (sizeof(_Ty) == 2) {
return __std_count_trivial_2(_First, _Last, static_cast<uint16_t>(_Val));
} else if constexpr (sizeof(_Ty) == 4) {
return __std_count_trivial_4(_First, _Last, static_cast<uint32_t>(_Val));
} else if constexpr (sizeof(_Ty) == 8) {
return __std_count_trivial_8(_First, _Last, static_cast<uint64_t>(_Val));
} else {
static_assert(_STD _Always_false<_Ty>, "Unexpected size");
}
}
template <class _Ty, class _TVal>
_Ty* __std_find_trivial(_Ty* _First, _Ty* _Last, const _TVal _Val) noexcept {
if constexpr (_STD is_pointer_v<_TVal> || _STD is_null_pointer_v<_TVal>) {
return __std_find_trivial(_First, _Last, reinterpret_cast<uintptr_t>(_Val));
} else if constexpr (sizeof(_Ty) == 1) {
return const_cast<_Ty*>(
static_cast<const _Ty*>(__std_find_trivial_1(_First, _Last, static_cast<uint8_t>(_Val))));
} else if constexpr (sizeof(_Ty) == 2) {
return const_cast<_Ty*>(
static_cast<const _Ty*>(__std_find_trivial_2(_First, _Last, static_cast<uint16_t>(_Val))));
} else if constexpr (sizeof(_Ty) == 4) {
return const_cast<_Ty*>(
static_cast<const _Ty*>(__std_find_trivial_4(_First, _Last, static_cast<uint32_t>(_Val))));
} else if constexpr (sizeof(_Ty) == 8) {
return const_cast<_Ty*>(
static_cast<const _Ty*>(__std_find_trivial_8(_First, _Last, static_cast<uint64_t>(_Val))));
} else {
static_assert(_STD _Always_false<_Ty>, "Unexpected size");
}
}
template <class _Ty, class _TVal>
_Ty* __std_find_trivial_unsized(_Ty* _First, const _TVal _Val) noexcept {
if constexpr (_STD is_pointer_v<_TVal> || _STD is_null_pointer_v<_TVal>) {
return __std_find_trivial_unsized(_First, reinterpret_cast<uintptr_t>(_Val));
} else if constexpr (sizeof(_Ty) == 1) {
return const_cast<_Ty*>(
static_cast<const _Ty*>(__std_find_trivial_unsized_1(_First, static_cast<uint8_t>(_Val))));
} else if constexpr (sizeof(_Ty) == 2) {
return const_cast<_Ty*>(
static_cast<const _Ty*>(__std_find_trivial_unsized_2(_First, static_cast<uint16_t>(_Val))));
} else if constexpr (sizeof(_Ty) == 4) {
return const_cast<_Ty*>(
static_cast<const _Ty*>(__std_find_trivial_unsized_4(_First, static_cast<uint32_t>(_Val))));
} else if constexpr (sizeof(_Ty) == 8) {
return const_cast<_Ty*>(
static_cast<const _Ty*>(__std_find_trivial_unsized_8(_First, static_cast<uint64_t>(_Val))));
} else {
static_assert(_STD _Always_false<_Ty>, "Unexpected size");
}
}
#endif // _USE_STD_VECTOR_ALGORITHMS
_STD_BEGIN
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_BIT_CAST _To _Bit_cast(const _From& _Val) noexcept {
#ifdef __CUDACC__
_To _To_obj; // assumes default-init
_CSTD memcpy(_STD addressof(_To_obj), _STD addressof(_Val), sizeof(_To));
return _To_obj;
#else // ^^^ workaround ^^^ / vvv no workaround vvv
return __builtin_bit_cast(_To, _Val);
#endif // ^^^ no workaround ^^^
}
template <class _Ty>
struct _Get_first_parameter;
template <template <class, class...> class _Ty, class _First, class... _Rest>
struct _Get_first_parameter<_Ty<_First, _Rest...>> { // given _Ty<_First, _Rest...>, extract _First
using type = _First;
};
template <class _Newfirst, class _Ty>
struct _Replace_first_parameter;
template <class _Newfirst, template <class, class...> class _Ty, class _First, class... _Rest>
struct _Replace_first_parameter<_Newfirst, _Ty<_First, _Rest...>> { // given _Ty<_First, _Rest...>, replace _First
using type = _Ty<_Newfirst, _Rest...>;
};
template <class _Ty, class = void>
struct _Get_element_type {
using type = typename _Get_first_parameter<_Ty>::type;
};
template <class _Ty>
struct _Get_element_type<_Ty, void_t<typename _Ty::element_type>> {
using type = typename _Ty::element_type;
};
template <class _Ty, class = void>
struct _Get_ptr_difference_type {
using type = ptrdiff_t;
};
template <class _Ty>
struct _Get_ptr_difference_type<_Ty, void_t<typename _Ty::difference_type>> {
using type = typename _Ty::difference_type;
};
template <class _Ty, class _Other, class = void>
struct _Get_rebind_alias {
using type = typename _Replace_first_parameter<_Other, _Ty>::type;
};
template <class _Ty, class _Other>
struct _Get_rebind_alias<_Ty, _Other, void_t<typename _Ty::template rebind<_Other>>> {
using type = typename _Ty::template rebind<_Other>;
};
template <class _Iter>
_NODISCARD constexpr void* _Voidify_iter(_Iter _It) noexcept {
if constexpr (is_pointer_v<_Iter>) {
return const_cast<void*>(static_cast<const volatile void*>(_It));
} else {
return const_cast<void*>(static_cast<const volatile void*>(_STD addressof(*_It)));
}
}
#if _HAS_CXX20
#ifdef __EDG__ // TRANSITION, DevCom-1691516
template <class _Ty, class... _Types,
class = void_t<decltype(::new (_STD declval<void*>()) _Ty(_STD declval<_Types>()...))>>
#else // ^^^ no workaround // workaround vvv
template <class _Ty, class... _Types,
void_t<decltype(::new (_STD declval<void*>()) _Ty(_STD declval<_Types>()...))>* = nullptr>
#endif // TRANSITION, DevCom-1691516
constexpr _Ty* construct_at(_Ty* const _Location, _Types&&... _Args) noexcept(
noexcept(::new (_Voidify_iter(_Location)) _Ty(_STD forward<_Types>(_Args)...))) /* strengthened */ {
_MSVC_CONSTEXPR return ::new (_Voidify_iter(_Location)) _Ty(_STD forward<_Types>(_Args)...);
}
#endif // _HAS_CXX20
template <class _Ty, class... _Types>
_CONSTEXPR20 void _Construct_in_place(_Ty& _Obj, _Types&&... _Args) noexcept(
is_nothrow_constructible_v<_Ty, _Types...>) {
#if _HAS_CXX20
if (_STD is_constant_evaluated()) {
_STD construct_at(_STD addressof(_Obj), _STD forward<_Types>(_Args)...);
} else
#endif // _HAS_CXX20
{
::new (_Voidify_iter(_STD addressof(_Obj))) _Ty(_STD forward<_Types>(_Args)...);
}
}
template <class _Ty>
void _Default_construct_in_place(_Ty& _Obj) noexcept(is_nothrow_default_constructible_v<_Ty>) {
::new (_Voidify_iter(_STD addressof(_Obj))) _Ty;
}
template <class _Ty>
struct pointer_traits {
using pointer = _Ty;
using element_type = typename _Get_element_type<_Ty>::type;
using difference_type = typename _Get_ptr_difference_type<_Ty>::type;
template <class _Other>
using rebind = typename _Get_rebind_alias<_Ty, _Other>::type;
using _Reftype = conditional_t<is_void_v<element_type>, char, element_type>&;
_NODISCARD static pointer pointer_to(_Reftype _Val) noexcept(noexcept(_Ty::pointer_to(_Val))) /* strengthened */ {
return _Ty::pointer_to(_Val);
}
};
template <class _Ty>
struct pointer_traits<_Ty*> {
using pointer = _Ty*;
using element_type = _Ty;
using difference_type = ptrdiff_t;
template <class _Other>
using rebind = _Other*;
using _Reftype = conditional_t<is_void_v<_Ty>, char, _Ty>&;
_NODISCARD static _CONSTEXPR20 pointer pointer_to(_Reftype _Val) noexcept {
return _STD addressof(_Val);
}
};
#if _HAS_CXX20
#ifdef __cpp_lib_concepts
template <class _Ty>
concept _Has_to_address = requires(const _Ty& _Val) {
typename pointer_traits<_Ty>;
pointer_traits<_Ty>::to_address(_Val);
};
#else // ^^^ Use concept / use variable template vvv
template <class _Ty, class = void>
inline constexpr bool _Has_to_address = false; // determines whether pointer_traits<_Ty> has to_address
template <class _Ty>
inline constexpr bool
_Has_to_address<_Ty, void_t<decltype(pointer_traits<_Ty>::to_address(_STD declval<const _Ty&>()))>> = true;
#endif // __cpp_lib_concepts
template <class _Ty>
_NODISCARD constexpr _Ty* to_address(_Ty* const _Val) noexcept {
static_assert(!is_function_v<_Ty>,
"N4810 20.10.4 [pointer.conversion]/2: The program is ill-formed if T is a function type.");
return _Val;
}
template <class _Ptr>
_NODISCARD constexpr auto to_address(const _Ptr& _Val) noexcept {
if constexpr (_Has_to_address<_Ptr>) {
return pointer_traits<_Ptr>::to_address(_Val);
} else {
return _STD to_address(_Val.operator->()); // plain pointer overload must come first
}
}
struct identity {
template <class _Ty>
_NODISCARD constexpr _Ty&& operator()(_Ty&& _Left) const noexcept {
return _STD forward<_Ty>(_Left);
}
using is_transparent = int;
};
#endif // _HAS_CXX20
// TRANSITION, VSO-386225
template <class _Fx>
struct _Ref_fn { // pass function object by value as a reference
template <class... _Args>
constexpr decltype(auto) operator()(_Args&&... _Vals) { // forward function call operator
if constexpr (is_member_pointer_v<_Fx>) {
return _STD invoke(_Fn, _STD forward<_Args>(_Vals)...);
} else {
return _Fn(_STD forward<_Args>(_Vals)...);
}
}
_Fx& _Fn;
};
template <class _Fn>
_INLINE_VAR constexpr bool _Pass_functor_by_value_v = conjunction_v<bool_constant<sizeof(_Fn) <= sizeof(void*)>,
is_trivially_copy_constructible<_Fn>, is_trivially_destructible<_Fn>>;
template <class _Fn, enable_if_t<_Pass_functor_by_value_v<_Fn>, int> = 0> // TRANSITION, if constexpr
constexpr _Fn _Pass_fn(_Fn _Val) { // pass functor by value
return _Val;
}
template <class _Fn, enable_if_t<!_Pass_functor_by_value_v<_Fn>, int> = 0>
constexpr _Ref_fn<_Fn> _Pass_fn(_Fn& _Val) { // pass functor by "reference"
return {_Val};
}
struct _Unused_parameter { // generic unused parameter struct
constexpr _Unused_parameter() noexcept = default;
template <class _Ty>
constexpr _Unused_parameter(_Ty&&) noexcept {}
};
using _Any_tag = _Unused_parameter; // generic fallback/default/"other" target for tag dispatch
template <class _Ty>
using _Algorithm_int_t = conditional_t<is_integral_v<_Ty>, _Ty, ptrdiff_t>;
#ifdef __cpp_lib_concepts
template <class _Ty>
concept _Destructible_object = is_object_v<_Ty> && destructible<_Ty>;
namespace ranges {
namespace _Iter_move {
void iter_move(); // Block unqualified name lookup
// clang-format off
template <class _Ty>
concept _Has_ADL = _Has_class_or_enum_type<_Ty> && requires(_Ty&& __t) {
iter_move(static_cast<_Ty&&>(__t));
};
template <class _Ty>
concept _Can_deref = requires(_Ty&& __t) {
*static_cast<_Ty&&>(__t);
};
class _Cpo {
private:
enum class _St { _None, _Custom, _Fallback };
template <class _Ty>
_NODISCARD static _CONSTEVAL _Choice_t<_St> _Choose() noexcept {
if constexpr (_Has_ADL<_Ty>) {
return {_St::_Custom, noexcept(iter_move(_STD declval<_Ty>()))};
} else if constexpr (_Can_deref<_Ty>) {
return {_St::_Fallback, noexcept(*_STD declval<_Ty>())};
} else {
return {_St::_None};
}
}
template <class _Ty>
static constexpr _Choice_t<_St> _Choice = _Choose<_Ty>();
public:
template <class _Ty>
requires (_Choice<_Ty>._Strategy != _St::_None)
_NODISCARD constexpr decltype(auto) operator()(_Ty&& _Val) const noexcept(_Choice<_Ty>._No_throw) {
constexpr _St _Strat = _Choice<_Ty>._Strategy;
if constexpr (_Strat == _St::_Custom) {
return iter_move(static_cast<_Ty&&>(_Val));
} else if constexpr (_Strat == _St::_Fallback) {
using _Ref = decltype(*static_cast<_Ty&&>(_Val));
if constexpr (is_lvalue_reference_v<_Ref>) {
return _STD move(*static_cast<_Ty&&>(_Val));
} else {
return *static_cast<_Ty&&>(_Val);
}
} else {
static_assert(_Always_false<_Ty>, "should be unreachable");
}
}
};
// clang-format on
} // namespace _Iter_move
inline namespace _Cpos {
inline constexpr _Iter_move::_Cpo iter_move;
}
} // namespace ranges
// iter_swap defined below since it depends on indirectly_movable_storable
// clang-format off
template <class _Ty>
requires _Dereferenceable<_Ty> && requires(_Ty& __t) {
{ _RANGES iter_move(__t) } -> _Can_reference;
}
using iter_rvalue_reference_t = decltype(_RANGES iter_move(_STD declval<_Ty&>()));
template <class _It>
concept _Indirectly_readable_impl = requires(const _It __i) {
typename iter_value_t<_It>;
typename iter_reference_t<_It>;
typename iter_rvalue_reference_t<_It>;
{ *__i } -> same_as<iter_reference_t<_It>>;
{ _RANGES iter_move(__i) } -> same_as<iter_rvalue_reference_t<_It>>;
} && common_reference_with<iter_reference_t<_It>&&, iter_value_t<_It>&>
&& common_reference_with<iter_reference_t<_It>&&, iter_rvalue_reference_t<_It>&&>
&& common_reference_with<iter_rvalue_reference_t<_It>&&, const iter_value_t<_It>&>;
template <class _It>
concept indirectly_readable = _Indirectly_readable_impl<remove_cvref_t<_It>>;
// clang-format on
template <indirectly_readable _Ty>
using iter_common_reference_t = common_reference_t<iter_reference_t<_Ty>, iter_value_t<_Ty>&>;
template <class _It, class _Ty>
concept indirectly_writable = requires(_It&& __i, _Ty&& __t) {
*__i = static_cast<_Ty&&>(__t);
*static_cast<_It&&>(__i) = static_cast<_Ty&&>(__t);
const_cast<const iter_reference_t<_It>&&>(*__i) = static_cast<_Ty&&>(__t);
const_cast<const iter_reference_t<_It>&&>(*static_cast<_It&&>(__i)) = static_cast<_Ty&&>(__t);
};
template <bool _Is_integer_class>
struct _Make_unsigned_like_impl {
template <class _Ty>
using _Apply = typename _Ty::_Unsigned_type;
};
template <>
struct _Make_unsigned_like_impl<false> {
template <class _Ty>
using _Apply = make_unsigned_t<_Ty>;
};
template <class _Ty>
using _Make_unsigned_like_t = typename _Make_unsigned_like_impl<_Integer_class<_Ty>>::template _Apply<_Ty>;
template <_Integer_like _Ty>
_NODISCARD constexpr auto _To_unsigned_like(const _Ty _Value) noexcept {
return static_cast<_Make_unsigned_like_t<_Ty>>(_Value);
}
template <bool _Is_integer_class>
struct _Make_signed_like_impl {
template <class _Ty>
using _Apply = typename _Ty::_Signed_type;
};
template <>
struct _Make_signed_like_impl<false> {
template <class _Ty>
using _Apply = make_signed_t<_Ty>;
};
template <class _Ty>
using _Make_signed_like_t = typename _Make_signed_like_impl<_Integer_class<_Ty>>::template _Apply<_Ty>;
template <_Integer_like _Ty>
_NODISCARD constexpr auto _To_signed_like(const _Ty _Value) noexcept {
return static_cast<_Make_signed_like_t<_Ty>>(_Value);
}
template <class _Ty>
concept incrementable = regular<_Ty> && weakly_incrementable<_Ty> && requires(_Ty __t) {
{ __t++ } -> same_as<_Ty>;
};
template <bool _Iterator_category_present>
struct _Iter_concept_impl2 {
template <class _It, class _Traits>
using _Apply = typename _Traits::iterator_category;
};
template <>
struct _Iter_concept_impl2<false> {
template <class _It, class _Traits>
requires _Is_from_primary<iterator_traits<_It>>
using _Apply = random_access_iterator_tag;
};
template <bool _Iterator_concept_present>
struct _Iter_concept_impl1 {
template <class _It, class _Traits>
using _Apply = typename _Traits::iterator_concept;
};
template <>
struct _Iter_concept_impl1<false> {
template <class _It, class _Traits>
using _Apply = typename _Iter_concept_impl2<_Has_member_iterator_category<_Traits>>::template _Apply<_It, _Traits>;
};
template <class _It, class _Traits = conditional_t<_Is_from_primary<iterator_traits<_It>>, _It, iterator_traits<_It>>>
using _Iter_concept =
typename _Iter_concept_impl1<_Has_member_iterator_concept<_Traits>>::template _Apply<_It, _Traits>;
// clang-format off
template <class _It>
concept input_iterator = input_or_output_iterator<_It> && indirectly_readable<_It>
&& requires { typename _Iter_concept<_It>; }
&& derived_from<_Iter_concept<_It>, input_iterator_tag>;
template <class _It, class _Ty>
concept output_iterator = input_or_output_iterator<_It> && indirectly_writable<_It, _Ty>
&& requires(_It __i, _Ty&& __t) {
*__i++ = static_cast<_Ty&&>(__t);
};
template <class _It>
concept forward_iterator = input_iterator<_It> && derived_from<_Iter_concept<_It>, forward_iterator_tag>
&& incrementable<_It> && sentinel_for<_It, _It>;
template <class _It>
concept bidirectional_iterator = forward_iterator<_It> && derived_from<_Iter_concept<_It>, bidirectional_iterator_tag>
&& requires(_It __i) {
{ --__i } -> same_as<_It&>;
{ __i-- } -> same_as<_It>;
};
template <class _It>
concept random_access_iterator = bidirectional_iterator<_It>
&& derived_from<_Iter_concept<_It>, random_access_iterator_tag> && totally_ordered<_It>
&& sized_sentinel_for<_It, _It> && requires(_It __i, const _It __j, const iter_difference_t<_It> __n) {
{ __i += __n } -> same_as<_It&>;
{ __j + __n } -> same_as<_It>;
{ __n + __j } -> same_as<_It>;
{ __i -= __n } -> same_as<_It&>;
{ __j - __n } -> same_as<_It>;
{ __j[__n] } -> same_as<iter_reference_t<_It>>;
};
template <class _It>
concept contiguous_iterator = random_access_iterator<_It>
&& derived_from<_Iter_concept<_It>, contiguous_iterator_tag>
&& is_lvalue_reference_v<iter_reference_t<_It>>
&& same_as<iter_value_t<_It>, remove_cvref_t<iter_reference_t<_It>>>
&& requires(const _It& __i) {
{ _STD to_address(__i) } -> same_as<add_pointer_t<iter_reference_t<_It>>>;
};
template <class _Fn, class _It>
concept indirectly_unary_invocable = indirectly_readable<_It>
&& copy_constructible<_Fn>
&& invocable<_Fn&, iter_value_t<_It>&>
&& invocable<_Fn&, iter_reference_t<_It>>
&& invocable<_Fn&, iter_common_reference_t<_It>>
&& common_reference_with<
invoke_result_t<_Fn&, iter_value_t<_It>&>,
invoke_result_t<_Fn&, iter_reference_t<_It>>>;
template <class _Fn, class _It>
concept indirectly_regular_unary_invocable = indirectly_readable<_It>
&& copy_constructible<_Fn>
&& regular_invocable<_Fn&, iter_value_t<_It>&>
&& regular_invocable<_Fn&, iter_reference_t<_It>>
&& regular_invocable<_Fn&, iter_common_reference_t<_It>>
&& common_reference_with<
invoke_result_t<_Fn&, iter_value_t<_It>&>,
invoke_result_t<_Fn&, iter_reference_t<_It>>>;
template <class _Fn, class _It>
concept indirect_unary_predicate = indirectly_readable<_It>
&& copy_constructible<_Fn>
&& predicate<_Fn&, iter_value_t<_It>&>
&& predicate<_Fn&, iter_reference_t<_It>>
&& predicate<_Fn&, iter_common_reference_t<_It>>;
template <class _Fn, class _It1, class _It2>
concept indirect_binary_predicate = indirectly_readable<_It1>
&& indirectly_readable<_It2>
&& copy_constructible<_Fn>
&& predicate<_Fn&, iter_value_t<_It1>&, iter_value_t<_It2>&>
&& predicate<_Fn&, iter_value_t<_It1>&, iter_reference_t<_It2>>
&& predicate<_Fn&, iter_reference_t<_It1>, iter_value_t<_It2>&>
&& predicate<_Fn&, iter_reference_t<_It1>, iter_reference_t<_It2>>
&& predicate<_Fn&, iter_common_reference_t<_It1>, iter_common_reference_t<_It2>>;
template <class _Fn, class _It1, class _It2 = _It1>
concept indirect_equivalence_relation = indirectly_readable<_It1>
&& indirectly_readable<_It2>
&& copy_constructible<_Fn>
&& equivalence_relation<_Fn&, iter_value_t<_It1>&, iter_value_t<_It2>&>
&& equivalence_relation<_Fn&, iter_value_t<_It1>&, iter_reference_t<_It2>>
&& equivalence_relation<_Fn&, iter_reference_t<_It1>, iter_value_t<_It2>&>
&& equivalence_relation<_Fn&, iter_reference_t<_It1>, iter_reference_t<_It2>>
&& equivalence_relation<_Fn&, iter_common_reference_t<_It1>, iter_common_reference_t<_It2>>;
template <class _Fn, class _It1, class _It2 = _It1>
concept indirect_strict_weak_order = indirectly_readable<_It1>
&& indirectly_readable<_It2>
&& copy_constructible<_Fn>
&& strict_weak_order<_Fn&, iter_value_t<_It1>&, iter_value_t<_It2>&>
&& strict_weak_order<_Fn&, iter_value_t<_It1>&, iter_reference_t<_It2>>
&& strict_weak_order<_Fn&, iter_reference_t<_It1>, iter_value_t<_It2>&>
&& strict_weak_order<_Fn&, iter_reference_t<_It1>, iter_reference_t<_It2>>
&& strict_weak_order<_Fn&, iter_common_reference_t<_It1>, iter_common_reference_t<_It2>>;
template <class _Fn, class... _Its>
requires (indirectly_readable<_Its> && ...)
&& invocable<_Fn, iter_reference_t<_Its>...>
using indirect_result_t = invoke_result_t<_Fn, iter_reference_t<_Its>...>;
// clang-format on
#pragma warning(push)
#pragma warning(disable : 5046) // '%s': Symbol involving type with internal linkage not defined
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundefined-internal" // function '%s' has internal linkage but is not defined
#endif // __clang__
template <indirectly_readable _It, indirectly_regular_unary_invocable<_It> _Proj>
struct projected {
using value_type = remove_cvref_t<indirect_result_t<_Proj&, _It>>;
#if defined(__clang__) || defined(__EDG__)
indirect_result_t<_Proj&, _It> operator*() const;
#else // ^^^ no workaround / workaround vvv
indirect_result_t<_Proj&, _It> operator*() const {
_CSTD abort(); // TRANSITION, VSO-1308657
}
#endif // ^^^ workaround ^^^
};
#ifdef __clang__
#pragma clang diagnostic pop
#endif // __clang__
#pragma warning(pop)
template <weakly_incrementable _It, class _Proj>
struct incrementable_traits<projected<_It, _Proj>> {
using difference_type = iter_difference_t<_It>;
};
template <class _In, class _Out>
concept indirectly_movable = indirectly_readable<_In> && indirectly_writable<_Out, iter_rvalue_reference_t<_In>>;
// clang-format off
template <class _In, class _Out>
concept indirectly_movable_storable = indirectly_movable<_In, _Out>
&& indirectly_writable<_Out, iter_value_t<_In>>
&& movable<iter_value_t<_In>>
&& constructible_from<iter_value_t<_In>, iter_rvalue_reference_t<_In>>
&& assignable_from<iter_value_t<_In>&, iter_rvalue_reference_t<_In> >;
// clang-format on
template <class _In, class _Out>
concept indirectly_copyable = indirectly_readable<_In> && indirectly_writable<_Out, iter_reference_t<_In>>;
// clang-format off
template <class _In, class _Out>
concept indirectly_copyable_storable = indirectly_copyable<_In, _Out>
&& indirectly_writable<_Out, iter_value_t<_In>&>
&& indirectly_writable<_Out, const iter_value_t<_In>&>
&& indirectly_writable<_Out, iter_value_t<_In>&&>
&& indirectly_writable<_Out, const iter_value_t<_In>&&>
&& copyable<iter_value_t<_In>>
&& constructible_from<iter_value_t<_In>, iter_reference_t<_In>>
&& assignable_from<iter_value_t<_In>&, iter_reference_t<_In>>;
// clang-format on
namespace ranges {
namespace _Iter_swap {
template <class _Ty1, class _Ty2>
void iter_swap(_Ty1, _Ty2) = delete;
// clang-format off
template <class _Ty1, class _Ty2>
concept _Has_ADL = (_Has_class_or_enum_type<_Ty1> || _Has_class_or_enum_type<_Ty2>)
&& requires(_Ty1&& __t1, _Ty2&& __t2) {
iter_swap(static_cast<_Ty1&&>(__t1), static_cast<_Ty2&&>(__t2));
};
template <class _Ty1, class _Ty2>
concept _Can_swap_references = indirectly_readable<remove_reference_t<_Ty1>>
&& indirectly_readable<remove_reference_t<_Ty2>>
&& swappable_with<iter_reference_t<_Ty1>, iter_reference_t<_Ty2>>;
template <class _Ty1, class _Ty2>
concept _Symmetric_indirectly_movable_storable =
indirectly_movable_storable<remove_reference_t<_Ty1>, remove_reference_t<_Ty2>>
&& indirectly_movable_storable<remove_reference_t<_Ty2>, remove_reference_t<_Ty1>>;
// clang-format on
template <class _Xty, class _Yty>
_NODISCARD constexpr iter_value_t<remove_reference_t<_Xty>> _Iter_exchange_move(_Xty&& _XVal,
_Yty&& _YVal) noexcept(noexcept(iter_value_t<remove_reference_t<_Xty>>(_RANGES iter_move(_XVal)))) {
iter_value_t<remove_reference_t<_Xty>> _Tmp(_RANGES iter_move(_XVal));
*_XVal = _RANGES iter_move(_YVal);
return _Tmp;
}
class _Cpo {
private:
enum class _St { _None, _Custom, _Swap, _Exchange };
template <class _Ty1, class _Ty2>
_NODISCARD static _CONSTEVAL _Choice_t<_St> _Choose() noexcept {
if constexpr (_Has_ADL<_Ty1, _Ty2>) {
return {_St::_Custom, noexcept(iter_swap(_STD declval<_Ty1>(), _STD declval<_Ty2>()))};
} else if constexpr (_Can_swap_references<_Ty1, _Ty2>) {
return {_St::_Swap, noexcept(_RANGES swap(*_STD declval<_Ty1>(), *_STD declval<_Ty2>()))};
} else if constexpr (_Symmetric_indirectly_movable_storable<_Ty1, _Ty2>) {
constexpr auto _Nothrow = noexcept(
*_STD declval<_Ty1>() = _Iter_exchange_move(_STD declval<_Ty2>(), _STD declval<_Ty1>()));
return {_St::_Exchange, _Nothrow};
} else {
return {_St::_None};
}
}
template <class _Ty1, class _Ty2>
static constexpr _Choice_t<_St> _Choice = _Choose<_Ty1, _Ty2>();
public:
// clang-format off
template <class _Ty1, class _Ty2>
requires (_Choice<_Ty1, _Ty2>._Strategy != _St::_None)
constexpr void operator()(_Ty1&& _Val1, _Ty2&& _Val2) const noexcept(_Choice<_Ty1, _Ty2>._No_throw) {
constexpr _St _Strat = _Choice<_Ty1, _Ty2>._Strategy;
if constexpr (_Strat == _St::_Custom) {
(void) iter_swap(static_cast<_Ty1&&>(_Val1), static_cast<_Ty2&&>(_Val2));
} else if constexpr (_Strat == _St::_Swap) {
_RANGES swap(*static_cast<_Ty1&&>(_Val1), *static_cast<_Ty2&&>(_Val2));
} else if constexpr (_Strat == _St::_Exchange) {
*static_cast<_Ty1&&>(_Val1) =
_Iter_exchange_move(static_cast<_Ty2&&>(_Val2), static_cast<_Ty1&&>(_Val1));
} else {
static_assert(_Always_false<_Ty1>, "should be unreachable");
}
}
// clang-format on
};
} // namespace _Iter_swap
inline namespace _Cpos {
inline constexpr _Iter_swap::_Cpo iter_swap;
}
} // namespace ranges
// clang-format off
template <class _It1, class _It2 = _It1>
concept indirectly_swappable = indirectly_readable<_It1> && indirectly_readable<_It2>
&& requires(const _It1 __i1, const _It2 __i2) {
_RANGES iter_swap(__i1, __i1);
_RANGES iter_swap(__i2, __i2);
_RANGES iter_swap(__i1, __i2);
_RANGES iter_swap(__i2, __i1);
};
// clang-format on
template <class _It1, class _It2, class _Rel, class _Proj1 = identity, class _Proj2 = identity>
concept indirectly_comparable = indirect_binary_predicate<_Rel, projected<_It1, _Proj1>, projected<_It2, _Proj2>>;
template <class _It>
concept permutable = forward_iterator<_It> && indirectly_movable_storable<_It, _It> && indirectly_swappable<_It, _It>;
namespace ranges {
struct less;
}
template <class _It1, class _It2, class _Out, class _Pr = ranges::less, class _Pj1 = identity, class _Pj2 = identity>
concept mergeable = input_iterator<_It1> && input_iterator<_It2> //
&& weakly_incrementable<_Out> //
&& indirectly_copyable<_It1, _Out> //
&& indirectly_copyable<_It2, _Out> //
&& indirect_strict_weak_order<_Pr, projected<_It1, _Pj1>, projected<_It2, _Pj2>>;
template <class _It, class _Pr = ranges::less, class _Proj = identity>
concept sortable = permutable<_It> && indirect_strict_weak_order<_Pr, projected<_It, _Proj>>;
template <class _Iter>
using _Iter_ref_t = iter_reference_t<_Iter>;
template <class _Iter>
using _Iter_value_t = iter_value_t<_Iter>;
template <class _Iter>
using _Iter_diff_t = iter_difference_t<_Iter>;
#else // ^^^ __cpp_lib_concepts / !__cpp_lib_concepts vvv
template <class _Iter>
using _Iter_ref_t = typename iterator_traits<_Iter>::reference;
template <class _Iter>
using _Iter_value_t = typename iterator_traits<_Iter>::value_type;
template <class _Iter>
using _Iter_diff_t = typename iterator_traits<_Iter>::difference_type;
#endif // __cpp_lib_concepts
template <class... _Iters>
using _Common_diff_t = common_type_t<_Iter_diff_t<_Iters>...>;
template <class _Iter>
using _Iter_cat_t = typename iterator_traits<_Iter>::iterator_category;
template <class _Ty, class = void>
_INLINE_VAR constexpr bool _Is_iterator_v = false;
template <class _Ty>
_INLINE_VAR constexpr bool _Is_iterator_v<_Ty, void_t<_Iter_cat_t<_Ty>>> = true;
template <class _Ty>
struct _Is_iterator : bool_constant<_Is_iterator_v<_Ty>> {};
template <class _Iter>
_INLINE_VAR constexpr bool _Is_input_iter_v = is_convertible_v<_Iter_cat_t<_Iter>, input_iterator_tag>;
template <class _Iter>
_INLINE_VAR constexpr bool _Is_fwd_iter_v = is_convertible_v<_Iter_cat_t<_Iter>, forward_iterator_tag>;
template <class _Iter>
_INLINE_VAR constexpr bool _Is_bidi_iter_v = is_convertible_v<_Iter_cat_t<_Iter>, bidirectional_iterator_tag>;
template <class _Iter>
_INLINE_VAR constexpr bool _Is_random_iter_v = is_convertible_v<_Iter_cat_t<_Iter>, random_access_iterator_tag>;
template <class, class = void>
struct _Is_checked_helper {}; // default definition, no longer used, retained due to pseudo-documentation
#if _ITERATOR_DEBUG_LEVEL != 0
template <class _Ty>
constexpr void _Verify_range(const _Ty* const _First, const _Ty* const _Last) noexcept {
// special case range verification for pointers
_STL_VERIFY(_First <= _Last, "transposed pointer range");
}
#endif // _ITERATOR_DEBUG_LEVEL != 0
template <class _Iter, class = void>
_INLINE_VAR constexpr bool _Allow_inheriting_unwrap_v = true;
template <class _Iter>
_INLINE_VAR constexpr bool _Allow_inheriting_unwrap_v<_Iter, void_t<typename _Iter::_Prevent_inheriting_unwrap>> =
is_same_v<_Iter, typename _Iter::_Prevent_inheriting_unwrap>;
template <class _Iter, class _Sentinel = _Iter, class = void>
_INLINE_VAR constexpr bool _Range_verifiable_v = false;
template <class _Iter, class _Sentinel>
_INLINE_VAR constexpr bool _Range_verifiable_v<_Iter, _Sentinel,
void_t<decltype(_Verify_range(_STD declval<const _Iter&>(), _STD declval<const _Sentinel&>()))>> =
_Allow_inheriting_unwrap_v<_Iter>;
template <class _Iter, class _Sentinel>
constexpr void _Adl_verify_range(const _Iter& _First, const _Sentinel& _Last) {
// check that [_First, _Last) forms an iterator range
if constexpr (_Range_verifiable_v<_Iter, _Sentinel>) {
_Verify_range(_First, _Last);
}
}
template <class _Iter, class = void>
_INLINE_VAR constexpr bool _Unwrappable_v = false;
template <class _Iter>
_INLINE_VAR constexpr bool _Unwrappable_v<_Iter,
void_t<decltype(_STD declval<_Remove_cvref_t<_Iter>&>()._Seek_to(_STD declval<_Iter>()._Unwrapped()))>> =
_Allow_inheriting_unwrap_v<_Remove_cvref_t<_Iter>>;
template <class _Iter>
_NODISCARD constexpr decltype(auto) _Get_unwrapped(_Iter&& _It) {
// unwrap an iterator previously subjected to _Adl_verify_range or otherwise validated
if constexpr (is_pointer_v<decay_t<_Iter>>) { // special-case pointers and arrays
return _It + 0;
} else if constexpr (_Unwrappable_v<_Iter>) {
return static_cast<_Iter&&>(_It)._Unwrapped();
} else {
return static_cast<_Iter&&>(_It);
}
}
template <class _Iter>
using _Unwrapped_t = _Remove_cvref_t<decltype(_Get_unwrapped(_STD declval<_Iter>()))>;
template <class _Iter, class = bool>
_INLINE_VAR constexpr bool _Do_unwrap_when_unverified_v = false;
template <class _Iter>
_INLINE_VAR constexpr bool
_Do_unwrap_when_unverified_v<_Iter, decltype(static_cast<bool>(_Iter::_Unwrap_when_unverified))> =
static_cast<bool>(_Iter::_Unwrap_when_unverified);
template <class _Iter>
_INLINE_VAR constexpr bool _Unwrappable_for_unverified_v =
_Unwrappable_v<_Iter>&& _Do_unwrap_when_unverified_v<_Remove_cvref_t<_Iter>>;
template <class _Iter>
_NODISCARD constexpr decltype(auto) _Get_unwrapped_unverified(_Iter&& _It) {
// unwrap an iterator not previously subjected to _Adl_verify_range
if constexpr (is_pointer_v<decay_t<_Iter>>) { // special-case pointers and arrays
return _It + 0;
} else if constexpr (_Unwrappable_for_unverified_v<_Iter>) {
return static_cast<_Iter&&>(_It)._Unwrapped();
} else {
return static_cast<_Iter&&>(_It);
}
}
template <class _Iter>
using _Unwrapped_unverified_t = _Remove_cvref_t<decltype(_Get_unwrapped_unverified(_STD declval<_Iter>()))>;
struct _Distance_unknown {
constexpr _Distance_unknown operator-() const noexcept {
return {};
}
};
template <class _Diff>
_INLINE_VAR constexpr _Diff _Max_possible_v{static_cast<make_unsigned_t<_Diff>>(-1) >> 1};
template <class _Diff>
_INLINE_VAR constexpr _Diff _Min_possible_v{-_Max_possible_v<_Diff> - 1};
template <class _Iter, class = void>
_INLINE_VAR constexpr bool _Offset_verifiable_v = false;
template <class _Iter>
_INLINE_VAR constexpr bool
_Offset_verifiable_v<_Iter, void_t<decltype(_STD declval<const _Iter&>()._Verify_offset(_Iter_diff_t<_Iter>{}))>> =
true;
template <class _Iter>
_INLINE_VAR constexpr bool _Unwrappable_for_offset_v =
_Unwrappable_v<_Iter>&& _Offset_verifiable_v<_Remove_cvref_t<_Iter>>;
template <class _Iter, class _Diff>
_NODISCARD constexpr decltype(auto) _Get_unwrapped_n(_Iter&& _It, const _Diff _Off) {
if constexpr (is_pointer_v<decay_t<_Iter>>) {
return _It + 0;
} else if constexpr (_Unwrappable_for_offset_v<_Iter> && is_integral_v<_Diff>) {
// ask an iterator to assert that the iterator moved _Off positions is valid, and unwrap
using _IDiff = _Iter_diff_t<_Remove_cvref_t<_Iter>>;
using _CDiff = common_type_t<_Diff, _IDiff>;
const auto _COff = static_cast<_CDiff>(_Off);
_STL_ASSERT(_COff <= static_cast<_CDiff>(_Max_possible_v<_IDiff>)
&& (is_unsigned_v<_Diff> || static_cast<_CDiff>(_Min_possible_v<_IDiff>) <= _COff),
"integer overflow");
(void) _COff;
_It._Verify_offset(static_cast<_IDiff>(_Off));
return static_cast<_Iter&&>(_It)._Unwrapped();
} else if constexpr (_Unwrappable_for_unverified_v<_Iter>) {
// iterator doesn't support offset-based asserts, or offset unknown; defer to unverified unwrap
return static_cast<_Iter&&>(_It)._Unwrapped();
} else {
// pass through iterator that doesn't participate in checking
return static_cast<_Iter&&>(_It);
}
}
template <class _Iter, class _UIter, class = void>
_INLINE_VAR constexpr bool _Wrapped_seekable_v = false;
template <class _Iter, class _UIter>
_INLINE_VAR constexpr bool
_Wrapped_seekable_v<_Iter, _UIter, void_t<decltype(_STD declval<_Iter&>()._Seek_to(_STD declval<_UIter>()))>> =
true;
template <class _Iter, class _UIter>
constexpr void _Seek_wrapped(_Iter& _It, _UIter&& _UIt) {