30 #ifndef _GLIBCXX_RANGES
31 #define _GLIBCXX_RANGES 1
33 #if __cplusplus > 201703L
35 #pragma GCC system_header
39 #if __cpp_lib_concepts
54 namespace std _GLIBCXX_VISIBILITY(default)
56 _GLIBCXX_BEGIN_NAMESPACE_VERSION
68 template<
typename _Tp>
69 inline constexpr
bool enable_view = derived_from<_Tp, view_base>;
71 template<
typename _Tp>
73 = range<_Tp> && movable<_Tp> && default_initializable<_Tp>
77 template<
typename _Tp>
78 concept viewable_range = range<_Tp>
79 && (borrowed_range<_Tp> || view<remove_cvref_t<_Tp>>);
83 template<
typename _Range>
84 concept __simple_view = view<_Range> && range<const _Range>
85 && same_as<iterator_t<_Range>, iterator_t<const _Range>>
86 && same_as<sentinel_t<_Range>, sentinel_t<const _Range>>;
88 template<
typename _It>
89 concept __has_arrow = input_iterator<_It>
90 && (is_pointer_v<_It> || requires(_It __it) { __it.operator->(); });
92 template<
typename _Tp,
typename _Up>
94 = !same_as<remove_cvref_t<_Tp>, remove_cvref_t<_Up>>;
97 template<
typename _Derived>
98 requires is_class_v<_Derived> && same_as<_Derived, remove_cv_t<_Derived>>
99 class view_interface :
public view_base
102 constexpr _Derived& _M_derived() noexcept
104 static_assert(derived_from<_Derived, view_interface<_Derived>>);
105 static_assert(view<_Derived>);
106 return static_cast<_Derived&
>(*this);
109 constexpr
const _Derived& _M_derived() const noexcept
111 static_assert(derived_from<_Derived, view_interface<_Derived>>);
112 static_assert(view<_Derived>);
113 return static_cast<const _Derived&
>(*this);
118 empty() requires forward_range<_Derived>
122 empty() const requires forward_range<const _Derived>
126 operator bool() requires requires { ranges::empty(_M_derived()); }
127 {
return !ranges::empty(_M_derived()); }
130 operator bool() const requires requires { ranges::empty(_M_derived()); }
131 {
return !ranges::empty(_M_derived()); }
134 data() requires contiguous_iterator<iterator_t<_Derived>>
139 requires range<const _Derived>
140 && contiguous_iterator<iterator_t<const _Derived>>
145 requires forward_range<_Derived>
146 && sized_sentinel_for<sentinel_t<_Derived>, iterator_t<_Derived>>
151 requires forward_range<const _Derived>
152 && sized_sentinel_for<sentinel_t<const _Derived>,
153 iterator_t<const _Derived>>
156 constexpr decltype(
auto)
157 front() requires forward_range<_Derived>
159 __glibcxx_assert(!empty());
163 constexpr decltype(
auto)
164 front() const requires forward_range<const _Derived>
166 __glibcxx_assert(!empty());
170 constexpr decltype(
auto)
172 requires bidirectional_range<_Derived> && common_range<_Derived>
174 __glibcxx_assert(!empty());
178 constexpr decltype(
auto)
180 requires bidirectional_range<const _Derived>
181 && common_range<const _Derived>
183 __glibcxx_assert(!empty());
187 template<random_access_range _Range = _Derived>
188 constexpr decltype(
auto)
189 operator[](range_difference_t<_Range> __n)
192 template<random_access_range _Range = const _Derived>
193 constexpr decltype(
auto)
194 operator[](range_difference_t<_Range> __n)
const
200 template<
class _From,
class _To>
201 concept __convertible_to_non_slicing = convertible_to<_From, _To>
202 && !(is_pointer_v<decay_t<_From>> && is_pointer_v<decay_t<_To>>
203 && __not_same_as<remove_pointer_t<decay_t<_From>>,
204 remove_pointer_t<decay_t<_To>>>);
206 template<
typename _Tp>
208 = !is_reference_v<_Tp> && requires(_Tp __t)
210 typename tuple_size<_Tp>::type;
211 requires derived_from<tuple_size<_Tp>, integral_constant<size_t, 2>>;
212 typename tuple_element_t<0, remove_const_t<_Tp>>;
213 typename tuple_element_t<1, remove_const_t<_Tp>>;
214 { get<0>(__t) } -> convertible_to<const tuple_element_t<0, _Tp>&>;
215 { get<1>(__t) } -> convertible_to<const tuple_element_t<1, _Tp>&>;
218 template<
typename _Tp,
typename _Up,
typename _Vp>
219 concept __pair_like_convertible_from
220 = !range<_Tp> && __pair_like<_Tp>
221 && constructible_from<_Tp, _Up, _Vp>
222 && __convertible_to_non_slicing<_Up, tuple_element_t<0, _Tp>>
223 && convertible_to<_Vp, tuple_element_t<1, _Tp>>;
227 enum class subrange_kind : bool { unsized, sized };
229 template<input_or_output_iterator _It, sentinel_for<_It> _Sent = _It,
230 subrange_kind _Kind = sized_sentinel_for<_Sent, _It>
231 ? subrange_kind::sized : subrange_kind::unsized>
232 requires (_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _It>)
233 class subrange :
public view_interface<subrange<_It, _Sent, _Kind>>
237 static const bool _S_store_size
238 = _Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _It>;
240 _It _M_begin = _It();
241 _Sent _M_end = _Sent();
243 template<
typename,
bool = _S_store_size>
247 template<
typename _Tp>
248 struct _Size<_Tp, true>
249 { __detail::__make_unsigned_like_t<_Tp> _M_size; };
251 [[no_unique_address]] _Size<iter_difference_t<_It>> _M_size = {};
254 subrange() =
default;
257 subrange(__detail::__convertible_to_non_slicing<_It>
auto __i, _Sent __s)
258 requires (!_S_store_size)
259 : _M_begin(
std::
move(__i)), _M_end(__s)
263 subrange(__detail::__convertible_to_non_slicing<_It>
auto __i, _Sent __s,
264 __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n)
265 requires (_Kind == subrange_kind::sized)
266 : _M_begin(
std::
move(__i)), _M_end(__s)
268 using __detail::__to_unsigned_like;
270 if constexpr (_S_store_size)
271 _M_size._M_size = __n;
274 template<__detail::__not_same_as<subrange> _Rng>
275 requires borrowed_range<_Rng>
276 && __detail::__convertible_to_non_slicing<iterator_t<_Rng>, _It>
277 && convertible_to<sentinel_t<_Rng>, _Sent>
279 subrange(_Rng&& __r) requires _S_store_size && sized_range<_Rng>
280 : subrange(__r, ranges::size(__r))
283 template<__detail::__not_same_as<subrange> _Rng>
284 requires borrowed_range<_Rng>
285 && __detail::__convertible_to_non_slicing<iterator_t<_Rng>, _It>
286 && convertible_to<sentinel_t<_Rng>, _Sent>
288 subrange(_Rng&& __r) requires (!_S_store_size)
289 : subrange{ranges::
begin(__r), ranges::
end(__r)}
292 template<borrowed_range _Rng>
293 requires __detail::__convertible_to_non_slicing<iterator_t<_Rng>, _It>
294 && convertible_to<sentinel_t<_Rng>, _Sent>
297 __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n)
298 requires (_Kind == subrange_kind::sized)
299 : subrange{ranges::
begin(__r), ranges::
end(__r), __n}
302 template<__detail::__not_same_as<subrange> _PairLike>
303 requires __detail::__pair_like_convertible_from<_PairLike,
const _It&,
306 operator _PairLike()
const
307 {
return _PairLike(_M_begin, _M_end); }
310 begin() const requires copyable<_It>
313 [[nodiscard]] constexpr _It
314 begin() requires (!copyable<_It>)
317 constexpr _Sent
end()
const {
return _M_end; }
319 constexpr
bool empty()
const {
return _M_begin == _M_end; }
321 constexpr __detail::__make_unsigned_like_t<iter_difference_t<_It>>
322 size() const requires (_Kind == subrange_kind::sized)
324 if constexpr (_S_store_size)
325 return _M_size._M_size;
327 return __detail::__to_unsigned_like(_M_end - _M_begin);
330 [[nodiscard]] constexpr subrange
331 next(iter_difference_t<_It> __n = 1) const &
332 requires forward_iterator<_It>
339 [[nodiscard]] constexpr subrange
340 next(iter_difference_t<_It> __n = 1) &&
346 [[nodiscard]] constexpr subrange
347 prev(iter_difference_t<_It> __n = 1) const
348 requires bidirectional_iterator<_It>
356 advance(iter_difference_t<_It> __n)
360 if constexpr (bidirectional_iterator<_It>)
364 if constexpr (_S_store_size)
365 _M_size._M_size += __detail::__to_unsigned_like(-__n);
369 __glibcxx_assert(__n >= 0);
371 if constexpr (_S_store_size)
372 _M_size._M_size -= __detail::__to_unsigned_like(__d);
377 template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
378 subrange(_It, _Sent) -> subrange<_It, _Sent>;
380 template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
382 __detail::__make_unsigned_like_t<iter_difference_t<_It>>)
383 -> subrange<_It, _Sent, subrange_kind::sized>;
385 template<borrowed_range _Rng>
387 -> subrange<iterator_t<_Rng>, sentinel_t<_Rng>,
389 || sized_sentinel_for<sentinel_t<_Rng>, iterator_t<_Rng>>)
390 ? subrange_kind::sized : subrange_kind::unsized>;
392 template<borrowed_range _Rng>
394 __detail::__make_unsigned_like_t<range_difference_t<_Rng>>)
395 -> subrange<iterator_t<_Rng>, sentinel_t<_Rng>, subrange_kind::sized>;
397 template<
size_t _Num,
class _It,
class _Sent, subrange_kind _Kind>
400 get(const subrange<_It, _Sent, _Kind>& __r)
402 if constexpr (_Num == 0)
408 template<
size_t _Num, class _It, class _Sent, subrange_kind _Kind>
411 get(subrange<_It, _Sent, _Kind>&& __r)
413 if constexpr (_Num == 0)
419 template<input_or_output_iterator _It, sentinel_for<_It> _Sent,
421 inline constexpr
bool
422 enable_borrowed_range<subrange<_It, _Sent, _Kind>> = true;
433 constexpr dangling() noexcept = default;
434 template<typename... _Args>
435 constexpr dangling(_Args&&...) noexcept { }
438 template<range _Range>
439 using borrowed_iterator_t = conditional_t<borrowed_range<_Range>,
443 template<range _Range>
444 using borrowed_subrange_t = conditional_t<borrowed_range<_Range>,
445 subrange<iterator_t<_Range>>,
448 template<
typename _Tp> requires is_object_v<_Tp>
450 :
public view_interface<empty_view<_Tp>>
453 static constexpr _Tp*
begin() noexcept {
return nullptr; }
454 static constexpr _Tp*
end() noexcept {
return nullptr; }
455 static constexpr _Tp* data() noexcept {
return nullptr; }
456 static constexpr
size_t size() noexcept {
return 0; }
457 static constexpr
bool empty() noexcept {
return true; }
460 template<
typename _Tp>
461 inline constexpr
bool enable_borrowed_range<empty_view<_Tp>> =
true;
465 template<copy_constructible _Tp> requires is_object_v<_Tp>
466 struct __box : std::optional<_Tp>
468 using std::optional<_Tp>::optional;
472 noexcept(is_nothrow_default_constructible_v<_Tp>)
473 requires default_initializable<_Tp>
477 __box(
const __box&) =
default;
478 __box(__box&&) =
default;
480 using std::optional<_Tp>::operator=;
485 operator=(
const __box& __that)
486 noexcept(is_nothrow_copy_constructible_v<_Tp>)
487 requires (!copyable<_Tp>)
490 this->emplace(*__that);
497 operator=(__box&& __that)
498 noexcept(is_nothrow_move_constructible_v<_Tp>)
499 requires (!movable<_Tp>)
512 template<copy_constructible _Tp> requires is_object_v<_Tp>
513 class single_view :
public view_interface<single_view<_Tp>>
516 single_view() =
default;
519 single_view(
const _Tp& __t)
524 single_view(_Tp&& __t)
530 template<
typename... _Args>
531 requires constructible_from<_Tp, _Args...>
533 single_view(in_place_t, _Args&&... __args)
542 begin() const noexcept
547 {
return data() + 1; }
551 {
return data() + 1; }
553 static constexpr
size_t
559 {
return _M_value.operator->(); }
562 data() const noexcept
563 {
return _M_value.operator->(); }
566 __detail::__box<_Tp> _M_value;
571 template<
typename _Wp>
572 constexpr
auto __to_signed_like(_Wp __w) noexcept
574 if constexpr (!integral<_Wp>)
575 return iter_difference_t<_Wp>();
576 else if constexpr (
sizeof(iter_difference_t<_Wp>) >
sizeof(_Wp))
577 return iter_difference_t<_Wp>(__w);
578 else if constexpr (
sizeof(ptrdiff_t) >
sizeof(_Wp))
579 return ptrdiff_t(__w);
580 else if constexpr (
sizeof(
long long) >
sizeof(_Wp))
581 return (
long long)(__w);
582 #ifdef __SIZEOF_INT128__
583 else if constexpr (__SIZEOF_INT128__ >
sizeof(_Wp))
584 return __int128(__w);
587 return __max_diff_type(__w);
590 template<
typename _Wp>
591 using __iota_diff_t = decltype(__to_signed_like(std::declval<_Wp>()));
593 template<
typename _It>
594 concept __decrementable = incrementable<_It>
597 { --__i } -> same_as<_It&>;
598 { __i-- } -> same_as<_It>;
601 template<
typename _It>
602 concept __advanceable = __decrementable<_It> && totally_ordered<_It>
603 && requires( _It __i,
const _It __j,
const __iota_diff_t<_It> __n)
605 { __i += __n } -> same_as<_It&>;
606 { __i -= __n } -> same_as<_It&>;
610 { __j - __j } -> convertible_to<__iota_diff_t<_It>>;
613 template<
typename _Winc>
614 struct __iota_view_iter_cat
617 template<incrementable _Winc>
618 struct __iota_view_iter_cat<_Winc>
619 {
using iterator_category = input_iterator_tag; };
622 template<weakly_incrementable _Winc,
623 semiregular _Bound = unreachable_sentinel_t>
624 requires std::__detail::__weakly_eq_cmp_with<_Winc, _Bound>
625 && semiregular<_Winc>
626 class iota_view :
public view_interface<iota_view<_Winc, _Bound>>
631 struct _Iterator : __detail::__iota_view_iter_cat<_Winc>
637 using namespace __detail;
638 if constexpr (__advanceable<_Winc>)
639 return random_access_iterator_tag{};
640 else if constexpr (__decrementable<_Winc>)
641 return bidirectional_iterator_tag{};
642 else if constexpr (incrementable<_Winc>)
643 return forward_iterator_tag{};
645 return input_iterator_tag{};
649 using iterator_concept = decltype(_S_iter_concept());
651 using value_type = _Winc;
652 using difference_type = __detail::__iota_diff_t<_Winc>;
654 _Iterator() =
default;
657 _Iterator(_Winc __value)
658 : _M_value(__value) { }
661 operator*() const noexcept(is_nothrow_copy_constructible_v<_Winc>)
676 operator++(
int) requires incrementable<_Winc>
684 operator--() requires __detail::__decrementable<_Winc>
691 operator--(
int) requires __detail::__decrementable<_Winc>
699 operator+=(difference_type __n) requires __detail::__advanceable<_Winc>
701 using __detail::__is_integer_like;
702 using __detail::__is_signed_integer_like;
703 if constexpr (__is_integer_like<_Winc>
704 && !__is_signed_integer_like<_Winc>)
706 if (__n >= difference_type(0))
707 _M_value +=
static_cast<_Winc
>(__n);
709 _M_value -=
static_cast<_Winc
>(-__n);
717 operator-=(difference_type __n) requires __detail::__advanceable<_Winc>
719 using __detail::__is_integer_like;
720 using __detail::__is_signed_integer_like;
721 if constexpr (__is_integer_like<_Winc>
722 && !__is_signed_integer_like<_Winc>)
724 if (__n >= difference_type(0))
725 _M_value -=
static_cast<_Winc
>(__n);
727 _M_value +=
static_cast<_Winc
>(-__n);
735 operator[](difference_type __n)
const
736 requires __detail::__advanceable<_Winc>
737 {
return _Winc(_M_value + __n); }
739 friend constexpr
bool
740 operator==(
const _Iterator& __x,
const _Iterator& __y)
741 requires equality_comparable<_Winc>
742 {
return __x._M_value == __y._M_value; }
744 friend constexpr
bool
745 operator<(
const _Iterator& __x,
const _Iterator& __y)
746 requires totally_ordered<_Winc>
747 {
return __x._M_value < __y._M_value; }
749 friend constexpr
bool
750 operator>(
const _Iterator& __x,
const _Iterator& __y)
751 requires totally_ordered<_Winc>
752 {
return __y < __x; }
754 friend constexpr
bool
755 operator<=(
const _Iterator& __x,
const _Iterator& __y)
756 requires totally_ordered<_Winc>
757 {
return !(__y < __x); }
759 friend constexpr
bool
760 operator>=(
const _Iterator& __x,
const _Iterator& __y)
761 requires totally_ordered<_Winc>
762 {
return !(__x < __y); }
764 #ifdef __cpp_lib_three_way_comparison
765 friend constexpr
auto
766 operator<=>(
const _Iterator& __x,
const _Iterator& __y)
767 requires totally_ordered<_Winc> && three_way_comparable<_Winc>
768 {
return __x._M_value <=> __y._M_value; }
771 friend constexpr _Iterator
772 operator+(_Iterator __i, difference_type __n)
773 requires __detail::__advanceable<_Winc>
774 {
return __i += __n; }
776 friend constexpr _Iterator
777 operator+(difference_type __n, _Iterator __i)
778 requires __detail::__advanceable<_Winc>
779 {
return __i += __n; }
781 friend constexpr _Iterator
782 operator-(_Iterator __i, difference_type __n)
783 requires __detail::__advanceable<_Winc>
784 {
return __i -= __n; }
786 friend constexpr difference_type
787 operator-(
const _Iterator& __x,
const _Iterator& __y)
788 requires __detail::__advanceable<_Winc>
790 using __detail::__is_integer_like;
791 using __detail::__is_signed_integer_like;
792 using _Dt = difference_type;
793 if constexpr (__is_integer_like<_Winc>)
795 if constexpr (__is_signed_integer_like<_Winc>)
796 return _Dt(_Dt(__x._M_value) - _Dt(__y._M_value));
798 return (__y._M_value > __x._M_value)
799 ? _Dt(-_Dt(__y._M_value - __x._M_value))
800 : _Dt(__x._M_value - __y._M_value);
803 return __x._M_value - __y._M_value;
807 _Winc _M_value = _Winc();
816 _M_equal(
const _Iterator& __x)
const
817 {
return __x._M_value == _M_bound; }
819 _Bound _M_bound = _Bound();
822 _Sentinel() =
default;
825 _Sentinel(_Bound __bound)
826 : _M_bound(__bound) { }
828 friend constexpr
bool
829 operator==(
const _Iterator& __x,
const _Sentinel& __y)
830 {
return __y._M_equal(__x); }
832 friend constexpr iter_difference_t<_Winc>
833 operator-(
const _Iterator& __x,
const _Sentinel& __y)
834 requires sized_sentinel_for<_Bound, _Winc>
835 {
return __x._M_value - __y._M_bound; }
837 friend constexpr iter_difference_t<_Winc>
838 operator-(
const _Sentinel& __x,
const _Iterator& __y)
839 requires sized_sentinel_for<_Bound, _Winc>
840 {
return -(__y - __x); }
843 _Winc _M_value = _Winc();
844 _Bound _M_bound = _Bound();
847 iota_view() =
default;
850 iota_view(_Winc __value)
855 iota_view(type_identity_t<_Winc> __value,
856 type_identity_t<_Bound> __bound)
857 : _M_value(__value), _M_bound(__bound)
859 if constexpr (totally_ordered_with<_Winc, _Bound>)
861 __glibcxx_assert(
bool(__value <= __bound) );
866 begin()
const {
return _Iterator{_M_value}; }
871 if constexpr (same_as<_Bound, unreachable_sentinel_t>)
872 return unreachable_sentinel;
874 return _Sentinel{_M_bound};
878 end() const requires same_as<_Winc, _Bound>
879 {
return _Iterator{_M_bound}; }
883 requires (same_as<_Winc, _Bound> && __detail::__advanceable<_Winc>)
884 || (integral<_Winc> && integral<_Bound>)
885 || sized_sentinel_for<_Bound, _Winc>
887 using __detail::__is_integer_like;
888 using __detail::__to_unsigned_like;
889 if constexpr (integral<_Winc> && integral<_Bound>)
892 return _Up(_M_bound) - _Up(_M_value);
894 else if constexpr (__is_integer_like<_Winc>)
895 return __to_unsigned_like(_M_bound) - __to_unsigned_like(_M_value);
897 return __to_unsigned_like(_M_bound - _M_value);
901 template<
typename _Winc,
typename _Bound>
902 requires (!__detail::__is_integer_like<_Winc>
903 || !__detail::__is_integer_like<_Bound>
904 || (__detail::__is_signed_integer_like<_Winc>
905 == __detail::__is_signed_integer_like<_Bound>))
906 iota_view(_Winc, _Bound) -> iota_view<_Winc, _Bound>;
908 template<weakly_incrementable _Winc, semiregular _Bound>
909 inline constexpr
bool
910 enable_borrowed_range<iota_view<_Winc, _Bound>> =
true;
914 template<
typename _Tp>
915 inline constexpr empty_view<_Tp> empty{};
919 template<
typename _Tp>
921 operator()(_Tp&& __e)
const
922 {
return single_view{std::forward<_Tp>(__e)}; }
925 inline constexpr _Single single{};
929 template<
typename _Tp>
931 operator()(_Tp&& __e)
const
932 {
return iota_view{std::forward<_Tp>(__e)}; }
934 template<
typename _Tp,
typename _Up>
936 operator()(_Tp&& __e, _Up&& __f)
const
937 {
return iota_view{std::forward<_Tp>(__e), std::forward<_Up>(__f)}; }
940 inline constexpr _Iota
iota{};
945 template<
typename _Val,
typename _CharT,
typename _Traits>
946 concept __stream_extractable
947 = requires(basic_istream<_CharT, _Traits>& is, _Val& t) { is >> t; };
950 template<movable _Val,
typename _CharT,
typename _Traits>
951 requires default_initializable<_Val>
952 && __detail::__stream_extractable<_Val, _CharT, _Traits>
953 class basic_istream_view
954 :
public view_interface<basic_istream_view<_Val, _CharT, _Traits>>
957 basic_istream_view() =
default;
960 basic_istream_view(basic_istream<_CharT, _Traits>& __stream)
967 if (_M_stream !=
nullptr)
968 *_M_stream >> _M_object;
969 return _Iterator{
this};
972 constexpr default_sentinel_t
974 {
return default_sentinel; }
977 basic_istream<_CharT, _Traits>* _M_stream =
nullptr;
978 _Val _M_object = _Val();
983 using iterator_concept = input_iterator_tag;
984 using difference_type = ptrdiff_t;
985 using value_type = _Val;
987 _Iterator() =
default;
990 _Iterator(basic_istream_view* __parent) noexcept
991 : _M_parent(__parent)
994 _Iterator(
const _Iterator&) =
delete;
995 _Iterator(_Iterator&&) =
default;
996 _Iterator& operator=(
const _Iterator&) =
delete;
997 _Iterator& operator=(_Iterator&&) =
default;
1002 __glibcxx_assert(_M_parent->_M_stream !=
nullptr);
1003 *_M_parent->_M_stream >> _M_parent->_M_object;
1014 __glibcxx_assert(_M_parent->_M_stream !=
nullptr);
1015 return _M_parent->_M_object;
1019 operator==(
const _Iterator& __x, default_sentinel_t)
1020 {
return __x._M_at_end(); }
1023 basic_istream_view* _M_parent =
nullptr;
1027 {
return _M_parent ==
nullptr || !*_M_parent->_M_stream; }
1033 template<
typename _Val,
typename _CharT,
typename _Traits>
1034 basic_istream_view<_Val, _CharT, _Traits>
1035 istream_view(basic_istream<_CharT, _Traits>& __s)
1036 {
return basic_istream_view<_Val, _CharT, _Traits>{__s}; }
1046 template<
bool _Present,
typename _Tp>
1047 using __maybe_present_t = conditional_t<_Present, _Tp, _Empty>;
1050 template<
bool _Const,
typename _Tp>
1051 using __maybe_const_t = conditional_t<_Const, const _Tp, _Tp>;
1059 template<
typename _Tp>
1060 inline constexpr
auto
1061 __maybe_refwrap(_Tp& __arg)
1062 {
return reference_wrapper<_Tp>{__arg}; }
1064 template<
typename _Tp>
1065 inline constexpr
auto
1066 __maybe_refwrap(
const _Tp& __arg)
1067 {
return reference_wrapper<const _Tp>{__arg}; }
1069 template<
typename _Tp>
1070 inline constexpr decltype(
auto)
1071 __maybe_refwrap(_Tp&& __arg)
1072 {
return std::forward<_Tp>(__arg); }
1074 template<
typename _Callable>
1075 struct _RangeAdaptorClosure;
1077 template<
typename _Callable>
1078 struct _RangeAdaptor
1081 [[no_unique_address]]
1082 __detail::__maybe_present_t<!is_default_constructible_v<_Callable>,
1083 _Callable> _M_callable;
1087 _RangeAdaptor(
const _Callable& = {})
1088 requires is_default_constructible_v<_Callable>
1092 _RangeAdaptor(_Callable __callable)
1093 requires (!is_default_constructible_v<_Callable>)
1094 : _M_callable(
std::
move(__callable))
1097 template<
typename... _Args>
1098 requires (
sizeof...(_Args) >= 1)
1100 operator()(_Args&&... __args)
const
1113 if constexpr (is_invocable_v<_Callable, _Args...>)
1115 static_assert(
sizeof...(_Args) != 1,
1116 "a _RangeAdaptor that accepts only one argument "
1117 "should be defined as a _RangeAdaptorClosure");
1120 return _Callable{}(std::forward<_Args>(__args)...);
1133 = [...__args(__maybe_refwrap(std::forward<_Args>(__args)))]
1134 <
typename _Range> (_Range&& __r) {
1138 return _Callable{}(std::forward<_Range>(__r),
1139 (
static_cast<unwrap_reference_t
1143 using _ClosureType = decltype(__closure);
1144 return _RangeAdaptorClosure<_ClosureType>(
std::move(__closure));
1149 template<
typename _Callable>
1150 _RangeAdaptor(_Callable) -> _RangeAdaptor<_Callable>;
1152 template<
typename _Callable>
1153 struct _RangeAdaptorClosure :
public _RangeAdaptor<_Callable>
1155 using _RangeAdaptor<_Callable>::_RangeAdaptor;
1157 template<viewable_range _Range>
1158 requires requires { declval<_Callable>()(declval<_Range>()); }
1160 operator()(_Range&& __r)
const
1162 if constexpr (is_default_constructible_v<_Callable>)
1163 return _Callable{}(std::forward<_Range>(__r));
1165 return this->_M_callable(std::forward<_Range>(__r));
1168 template<viewable_range _Range>
1169 requires requires { declval<_Callable>()(declval<_Range>()); }
1170 friend constexpr
auto
1171 operator|(_Range&& __r,
const _RangeAdaptorClosure& __o)
1172 {
return __o(std::forward<_Range>(__r)); }
1174 template<
typename _Tp>
1175 friend constexpr
auto
1176 operator|(
const _RangeAdaptorClosure<_Tp>& __x,
1177 const _RangeAdaptorClosure& __y)
1179 if constexpr (is_default_constructible_v<_Tp>
1180 && is_default_constructible_v<_Callable>)
1182 auto __closure = [] <
typename _Up> (_Up&& __e) {
1183 return std::forward<_Up>(__e) | decltype(__x){} | decltype(__y){};
1185 return _RangeAdaptorClosure<decltype(__closure)>(__closure);
1187 else if constexpr (is_default_constructible_v<_Tp>
1188 && !is_default_constructible_v<_Callable>)
1190 auto __closure = [__y] <
typename _Up> (_Up&& __e) {
1191 return std::forward<_Up>(__e) | decltype(__x){} | __y;
1193 return _RangeAdaptorClosure<decltype(__closure)>(__closure);
1195 else if constexpr (!is_default_constructible_v<_Tp>
1196 && is_default_constructible_v<_Callable>)
1198 auto __closure = [__x] <
typename _Up> (_Up&& __e) {
1199 return std::forward<_Up>(__e) | __x | decltype(__y){};
1201 return _RangeAdaptorClosure<decltype(__closure)>(__closure);
1205 auto __closure = [__x, __y] <
typename _Up> (_Up&& __e) {
1206 return std::forward<_Up>(__e) | __x | __y;
1208 return _RangeAdaptorClosure<decltype(__closure)>(__closure);
1213 template<
typename _Callable>
1214 _RangeAdaptorClosure(_Callable) -> _RangeAdaptorClosure<_Callable>;
1218 template<range _Range> requires is_object_v<_Range>
1219 class ref_view :
public view_interface<ref_view<_Range>>
1222 _Range* _M_r =
nullptr;
1224 static void _S_fun(_Range&);
1225 static void _S_fun(_Range&&) =
delete;
1229 ref_view() noexcept = default;
1231 template<__detail::__not_same_as<ref_view> _Tp>
1232 requires convertible_to<_Tp, _Range&>
1233 && requires { _S_fun(declval<_Tp>()); }
1243 constexpr iterator_t<_Range>
1247 constexpr sentinel_t<_Range>
1252 empty() const requires requires { ranges::empty(*_M_r); }
1253 {
return ranges::empty(*_M_r); }
1256 size() const requires sized_range<_Range>
1257 {
return ranges::size(*_M_r); }
1260 data() const requires contiguous_range<_Range>
1261 {
return ranges::data(*_M_r); }
1264 template<
typename _Range>
1265 ref_view(_Range&) -> ref_view<_Range>;
1267 template<
typename _Tp>
1268 inline constexpr
bool enable_borrowed_range<ref_view<_Tp>> =
true;
1272 inline constexpr __adaptor::_RangeAdaptorClosure all
1273 = [] <viewable_range _Range> (_Range&& __r)
1275 if constexpr (view<decay_t<_Range>>)
1277 else if constexpr (requires { ref_view{std::forward<_Range>(__r)}; })
1278 return ref_view{std::forward<_Range>(__r)};
1280 return subrange{std::forward<_Range>(__r)};
1283 template<viewable_range _Range>
1284 using all_t = decltype(all(std::declval<_Range>()));
1292 template<
typename _Iter,
typename _Sent,
typename _Tp>
1294 find(_Iter __first, _Sent __last,
const _Tp& __value)
1296 while (__first != __last
1297 && !(
bool)(*__first == __value))
1302 template<
typename _Iter,
typename _Sent,
typename _Pred>
1304 find_if(_Iter __first, _Sent __last, _Pred __pred)
1306 while (__first != __last
1312 template<
typename _Iter,
typename _Sent,
typename _Pred>
1314 find_if_not(_Iter __first, _Sent __last, _Pred __pred)
1316 while (__first != __last
1322 template<
typename _Iter1,
typename _Sent1,
typename _Iter2,
typename _Sent2>
1323 constexpr pair<_Iter1, _Iter2>
1324 mismatch(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2)
1326 while (__first1 != __last1 && __first2 != __last2
1327 && (
bool)ranges::equal_to{}(*__first1, *__first2))
1338 template<range _Range>
1339 struct _CachedPosition
1342 _M_has_value()
const
1345 constexpr iterator_t<_Range>
1346 _M_get(
const _Range&)
const
1348 __glibcxx_assert(
false);
1353 _M_set(
const _Range&,
const iterator_t<_Range>&)
const
1357 template<forward_range _Range>
1358 struct _CachedPosition<_Range>
1361 iterator_t<_Range> _M_iter{};
1365 _M_has_value()
const
1366 {
return _M_iter != iterator_t<_Range>{}; }
1368 constexpr iterator_t<_Range>
1369 _M_get(
const _Range&)
const
1371 __glibcxx_assert(_M_has_value());
1376 _M_set(
const _Range&,
const iterator_t<_Range>& __it)
1378 __glibcxx_assert(!_M_has_value());
1383 template<random_access_range _Range>
1384 requires (
sizeof(range_difference_t<_Range>)
1385 <=
sizeof(iterator_t<_Range>))
1386 struct _CachedPosition<_Range>
1389 range_difference_t<_Range> _M_offset = -1;
1393 _M_has_value()
const
1394 {
return _M_offset >= 0; }
1396 constexpr iterator_t<_Range>
1397 _M_get(_Range& __r)
const
1399 __glibcxx_assert(_M_has_value());
1404 _M_set(_Range& __r,
const iterator_t<_Range>& __it)
1406 __glibcxx_assert(!_M_has_value());
1414 template<
typename _Base>
1415 struct __filter_view_iter_cat
1418 template<forward_range _Base>
1419 struct __filter_view_iter_cat<_Base>
1425 using _Cat =
typename iterator_traits<iterator_t<_Base>>::iterator_category;
1426 if constexpr (derived_from<_Cat, bidirectional_iterator_tag>)
1427 return bidirectional_iterator_tag{};
1428 else if constexpr (derived_from<_Cat, forward_iterator_tag>)
1429 return forward_iterator_tag{};
1434 using iterator_category = decltype(_S_iter_cat());
1438 template<input_range _Vp,
1439 indirect_unary_predicate<iterator_t<_Vp>> _Pred>
1440 requires view<_Vp> && is_object_v<_Pred>
1441 class filter_view :
public view_interface<filter_view<_Vp, _Pred>>
1446 struct _Iterator : __detail::__filter_view_iter_cat<_Vp>
1449 static constexpr
auto
1452 if constexpr (bidirectional_range<_Vp>)
1453 return bidirectional_iterator_tag{};
1454 else if constexpr (forward_range<_Vp>)
1455 return forward_iterator_tag{};
1457 return input_iterator_tag{};
1462 using _Vp_iter = iterator_t<_Vp>;
1464 _Vp_iter _M_current = _Vp_iter();
1465 filter_view* _M_parent =
nullptr;
1468 using iterator_concept = decltype(_S_iter_concept());
1470 using value_type = range_value_t<_Vp>;
1471 using difference_type = range_difference_t<_Vp>;
1473 _Iterator() =
default;
1476 _Iterator(filter_view* __parent, _Vp_iter __current)
1477 : _M_current(
std::
move(__current)),
1483 requires copyable<_Vp_iter>
1484 {
return _M_current; }
1490 constexpr range_reference_t<_Vp>
1492 {
return *_M_current; }
1496 requires __detail::__has_arrow<_Vp_iter>
1497 && copyable<_Vp_iter>
1498 {
return _M_current; }
1500 constexpr _Iterator&
1503 _M_current = __detail::find_if(
std::move(++_M_current),
1505 std::ref(*_M_parent->_M_pred));
1514 operator++(
int) requires forward_range<_Vp>
1521 constexpr _Iterator&
1522 operator--() requires bidirectional_range<_Vp>
1531 operator--(
int) requires bidirectional_range<_Vp>
1538 friend constexpr
bool
1539 operator==(
const _Iterator& __x,
const _Iterator& __y)
1540 requires equality_comparable<_Vp_iter>
1541 {
return __x._M_current == __y._M_current; }
1543 friend constexpr range_rvalue_reference_t<_Vp>
1544 iter_move(
const _Iterator& __i)
1545 noexcept(noexcept(ranges::iter_move(__i._M_current)))
1546 {
return ranges::iter_move(__i._M_current); }
1548 friend constexpr
void
1549 iter_swap(
const _Iterator& __x,
const _Iterator& __y)
1550 noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current)))
1551 requires indirectly_swappable<_Vp_iter>
1552 { ranges::iter_swap(__x._M_current, __y._M_current); }
1558 sentinel_t<_Vp> _M_end = sentinel_t<_Vp>();
1561 __equal(
const _Iterator& __i)
const
1562 {
return __i._M_current == _M_end; }
1565 _Sentinel() =
default;
1568 _Sentinel(filter_view* __parent)
1569 : _M_end(ranges::
end(__parent->_M_base))
1572 constexpr sentinel_t<_Vp>
1576 friend constexpr
bool
1577 operator==(
const _Iterator& __x,
const _Sentinel& __y)
1578 {
return __y.__equal(__x); }
1581 _Vp _M_base = _Vp();
1582 __detail::__box<_Pred> _M_pred;
1583 [[no_unique_address]] __detail::_CachedPosition<_Vp> _M_cached_begin;
1586 filter_view() =
default;
1589 filter_view(_Vp
__base, _Pred __pred)
1594 base() const& requires copy_constructible<_Vp>
1601 constexpr
const _Pred&
1603 {
return *_M_pred; }
1608 if (_M_cached_begin._M_has_value())
1609 return {
this, _M_cached_begin._M_get(_M_base)};
1611 __glibcxx_assert(_M_pred.has_value());
1614 std::ref(*_M_pred));
1615 _M_cached_begin._M_set(_M_base, __it);
1622 if constexpr (common_range<_Vp>)
1625 return _Sentinel{
this};
1629 template<
typename _Range,
typename _Pred>
1630 filter_view(_Range&&, _Pred) -> filter_view<views::all_t<_Range>, _Pred>;
1634 inline constexpr __adaptor::_RangeAdaptor filter
1635 = [] <viewable_range _Range,
typename _Pred> (_Range&& __r, _Pred&& __p)
1637 return filter_view{std::forward<_Range>(__r), std::forward<_Pred>(__p)};
1641 template<input_range _Vp, copy_constructible _Fp>
1642 requires view<_Vp> && is_object_v<_Fp>
1643 && regular_invocable<_Fp&, range_reference_t<_Vp>>
1644 && std::__detail::__can_reference<invoke_result_t<_Fp&,
1645 range_reference_t<_Vp>>>
1646 class transform_view :
public view_interface<transform_view<_Vp, _Fp>>
1649 template<
bool _Const>
1650 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
1652 template<
bool _Const>
1656 template<
bool _Const>
1657 requires forward_range<_Base<_Const>>
1658 struct __iter_cat<_Const>
1664 using _Base = transform_view::_Base<_Const>;
1665 using _Res = invoke_result_t<_Fp&, range_reference_t<_Base>>;
1666 if constexpr (is_lvalue_reference_v<_Res>)
1669 =
typename iterator_traits<iterator_t<_Base>>::iterator_category;
1670 if constexpr (derived_from<_Cat, contiguous_iterator_tag>)
1671 return random_access_iterator_tag{};
1676 return input_iterator_tag{};
1679 using iterator_category = decltype(_S_iter_cat());
1682 template<
bool _Const>
1685 template<
bool _Const>
1686 struct _Iterator : __iter_cat<_Const>
1689 using _Parent = __detail::__maybe_const_t<_Const, transform_view>;
1690 using _Base = transform_view::_Base<_Const>;
1695 if constexpr (random_access_range<_Vp>)
1696 return random_access_iterator_tag{};
1697 else if constexpr (bidirectional_range<_Vp>)
1698 return bidirectional_iterator_tag{};
1699 else if constexpr (forward_range<_Vp>)
1700 return forward_iterator_tag{};
1702 return input_iterator_tag{};
1705 using _Base_iter = iterator_t<_Base>;
1707 _Base_iter _M_current = _Base_iter();
1708 _Parent* _M_parent =
nullptr;
1711 using iterator_concept = decltype(_S_iter_concept());
1714 = remove_cvref_t<invoke_result_t<_Fp&, range_reference_t<_Base>>>;
1715 using difference_type = range_difference_t<_Base>;
1717 _Iterator() =
default;
1720 _Iterator(_Parent* __parent, _Base_iter __current)
1721 : _M_current(
std::
move(__current)),
1726 _Iterator(_Iterator<!_Const> __i)
1728 && convertible_to<iterator_t<_Vp>, _Base_iter>
1729 : _M_current(
std::move(__i._M_current)), _M_parent(__i._M_parent)
1732 constexpr _Base_iter
1734 requires copyable<_Base_iter>
1735 {
return _M_current; }
1737 constexpr _Base_iter
1741 constexpr decltype(
auto)
1743 noexcept(noexcept(
std::
__invoke(*_M_parent->_M_fun, *_M_current)))
1746 constexpr _Iterator&
1758 operator++(
int) requires forward_range<_Base>
1765 constexpr _Iterator&
1766 operator--() requires bidirectional_range<_Base>
1773 operator--(
int) requires bidirectional_range<_Base>
1780 constexpr _Iterator&
1781 operator+=(difference_type __n) requires random_access_range<_Base>
1787 constexpr _Iterator&
1788 operator-=(difference_type __n) requires random_access_range<_Base>
1794 constexpr decltype(
auto)
1795 operator[](difference_type __n) const
1796 requires random_access_range<_Base>
1797 {
return std::__invoke(*_M_parent->_M_fun, _M_current[__n]); }
1799 friend constexpr
bool
1800 operator==(
const _Iterator& __x,
const _Iterator& __y)
1801 requires equality_comparable<_Base_iter>
1802 {
return __x._M_current == __y._M_current; }
1804 friend constexpr
bool
1805 operator<(
const _Iterator& __x,
const _Iterator& __y)
1806 requires random_access_range<_Base>
1807 {
return __x._M_current < __y._M_current; }
1809 friend constexpr
bool
1810 operator>(
const _Iterator& __x,
const _Iterator& __y)
1811 requires random_access_range<_Base>
1812 {
return __y < __x; }
1814 friend constexpr
bool
1815 operator<=(
const _Iterator& __x,
const _Iterator& __y)
1816 requires random_access_range<_Base>
1817 {
return !(__y < __x); }
1819 friend constexpr
bool
1820 operator>=(
const _Iterator& __x,
const _Iterator& __y)
1821 requires random_access_range<_Base>
1822 {
return !(__x < __y); }
1824 #ifdef __cpp_lib_three_way_comparison
1825 friend constexpr
auto
1826 operator<=>(
const _Iterator& __x,
const _Iterator& __y)
1827 requires random_access_range<_Base>
1828 && three_way_comparable<_Base_iter>
1829 {
return __x._M_current <=> __y._M_current; }
1832 friend constexpr _Iterator
1833 operator+(_Iterator __i, difference_type __n)
1834 requires random_access_range<_Base>
1835 {
return {__i._M_parent, __i._M_current + __n}; }
1837 friend constexpr _Iterator
1838 operator+(difference_type __n, _Iterator __i)
1839 requires random_access_range<_Base>
1840 {
return {__i._M_parent, __i._M_current + __n}; }
1842 friend constexpr _Iterator
1843 operator-(_Iterator __i, difference_type __n)
1844 requires random_access_range<_Base>
1845 {
return {__i._M_parent, __i._M_current - __n}; }
1849 friend constexpr difference_type
1850 operator-(
const _Iterator& __x,
const _Iterator& __y)
1851 requires sized_sentinel_for<iterator_t<_Base>, iterator_t<_Base>>
1852 {
return __x._M_current - __y._M_current; }
1854 friend constexpr decltype(
auto)
1855 iter_move(const _Iterator& __i) noexcept(noexcept(*__i))
1857 if constexpr (is_lvalue_reference_v<decltype(*__i)>)
1863 friend _Iterator<!_Const>;
1864 template<
bool> friend struct _Sentinel;
1867 template<
bool _Const>
1871 using _Parent = __detail::__maybe_const_t<_Const, transform_view>;
1872 using _Base = transform_view::_Base<_Const>;
1874 template<
bool _Const2>
1876 __distance_from(
const _Iterator<_Const2>& __i)
const
1877 {
return _M_end - __i._M_current; }
1879 template<
bool _Const2>
1881 __equal(
const _Iterator<_Const2>& __i)
const
1882 {
return __i._M_current == _M_end; }
1884 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
1887 _Sentinel() =
default;
1890 _Sentinel(sentinel_t<_Base> __end)
1895 _Sentinel(_Sentinel<!_Const> __i)
1897 && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
1901 constexpr sentinel_t<_Base>
1905 template<
bool _Const2>
1906 requires sentinel_for<sentinel_t<_Base>,
1907 iterator_t<__detail::__maybe_const_t<_Const2, _Vp>>>
1908 friend constexpr
bool
1909 operator==(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
1910 {
return __y.__equal(__x); }
1912 template<
bool _Const2,
1913 typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
1914 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
1915 friend constexpr range_difference_t<_Base2>
1916 operator-(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
1917 {
return -__y.__distance_from(__x); }
1919 template<
bool _Const2,
1920 typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
1921 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
1922 friend constexpr range_difference_t<_Base2>
1923 operator-(
const _Sentinel& __y,
const _Iterator<_Const2>& __x)
1924 {
return __y.__distance_from(__x); }
1926 friend _Sentinel<!_Const>;
1929 _Vp _M_base = _Vp();
1930 __detail::__box<_Fp> _M_fun;
1933 transform_view() =
default;
1936 transform_view(_Vp
__base, _Fp __fun)
1941 base() const& requires copy_constructible<_Vp>
1942 {
return _M_base ; }
1948 constexpr _Iterator<false>
1952 constexpr _Iterator<true>
1954 requires range<const _Vp>
1955 && regular_invocable<const _Fp&, range_reference_t<const _Vp>>
1958 constexpr _Sentinel<false>
1960 {
return _Sentinel<false>{
ranges::end(_M_base)}; }
1962 constexpr _Iterator<false>
1963 end() requires common_range<_Vp>
1964 {
return _Iterator<false>{
this,
ranges::end(_M_base)}; }
1966 constexpr _Sentinel<true>
1968 requires range<const _Vp>
1969 && regular_invocable<const _Fp&, range_reference_t<const _Vp>>
1972 constexpr _Iterator<true>
1974 requires common_range<const _Vp>
1975 && regular_invocable<const _Fp&, range_reference_t<const _Vp>>
1976 {
return _Iterator<true>{
this,
ranges::end(_M_base)}; }
1979 size() requires sized_range<_Vp>
1980 {
return ranges::size(_M_base); }
1983 size() const requires sized_range<const _Vp>
1984 {
return ranges::size(_M_base); }
1987 template<
typename _Range,
typename _Fp>
1988 transform_view(_Range&&, _Fp) -> transform_view<views::all_t<_Range>, _Fp>;
1992 inline constexpr __adaptor::_RangeAdaptor transform
1993 = [] <viewable_range _Range,
typename _Fp> (_Range&& __r, _Fp&& __f)
1995 return transform_view{std::forward<_Range>(__r), std::forward<_Fp>(__f)};
2000 class take_view :
public view_interface<take_view<_Vp>>
2003 template<
bool _Const>
2004 using _CI = counted_iterator<
2005 iterator_t<__detail::__maybe_const_t<_Const, _Vp>>>;
2007 template<
bool _Const>
2011 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2012 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
2015 _Sentinel() =
default;
2018 _Sentinel(sentinel_t<_Base> __end)
2023 _Sentinel(_Sentinel<!_Const> __s)
2024 requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
2028 constexpr sentinel_t<_Base>
2032 friend constexpr
bool
2033 operator==(
const _CI<_Const>& __y,
const _Sentinel& __x)
2034 {
return __y.count() == 0 || __y.base() == __x._M_end; }
2036 template<
bool _OtherConst = !_Const,
2037 typename _Base2 = __detail::__maybe_const_t<_OtherConst, _Vp>>
2038 requires sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
2039 friend constexpr
bool
2040 operator==(
const _CI<_OtherConst>& __y,
const _Sentinel& __x)
2041 {
return __y.count() == 0 || __y.base() == __x._M_end; }
2043 friend _Sentinel<!_Const>;
2046 _Vp _M_base = _Vp();
2047 range_difference_t<_Vp> _M_count = 0;
2050 take_view() =
default;
2053 take_view(_Vp base, range_difference_t<_Vp> __count)
2058 base() const& requires copy_constructible<_Vp>
2066 begin() requires (!__detail::__simple_view<_Vp>)
2068 if constexpr (sized_range<_Vp>)
2070 if constexpr (random_access_range<_Vp>)
2083 begin() const requires range<const _Vp>
2085 if constexpr (sized_range<const _Vp>)
2087 if constexpr (random_access_range<const _Vp>)
2100 end() requires (!__detail::__simple_view<_Vp>)
2102 if constexpr (sized_range<_Vp>)
2104 if constexpr (random_access_range<_Vp>)
2107 return default_sentinel;
2114 end() const requires range<const _Vp>
2116 if constexpr (sized_range<const _Vp>)
2118 if constexpr (random_access_range<const _Vp>)
2121 return default_sentinel;
2128 size() requires sized_range<_Vp>
2130 auto __n = ranges::size(_M_base);
2131 return std::min(__n,
static_cast<decltype(__n)
>(_M_count));
2135 size() const requires sized_range<const _Vp>
2137 auto __n = ranges::size(_M_base);
2138 return std::min(__n,
static_cast<decltype(__n)
>(_M_count));
2145 template<
typename _Range>
2146 take_view(_Range&&, range_difference_t<_Range>)
2147 -> take_view<views::all_t<_Range>>;
2149 template<
typename _Tp>
2150 inline constexpr
bool enable_borrowed_range<take_view<_Tp>>
2151 = enable_borrowed_range<_Tp>;
2155 inline constexpr __adaptor::_RangeAdaptor take
2156 = [] <viewable_range _Range,
typename _Tp> (_Range&& __r, _Tp&& __n)
2158 return take_view{std::forward<_Range>(__r), std::forward<_Tp>(__n)};
2162 template<view _Vp,
typename _Pred>
2163 requires input_range<_Vp> && is_object_v<_Pred>
2164 && indirect_unary_predicate<const _Pred, iterator_t<_Vp>>
2165 class take_while_view :
public view_interface<take_while_view<_Vp, _Pred>>
2167 template<
bool _Const>
2171 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2173 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
2174 const _Pred* _M_pred =
nullptr;
2177 _Sentinel() =
default;
2180 _Sentinel(sentinel_t<_Base> __end,
const _Pred* __pred)
2181 : _M_end(__end), _M_pred(__pred)
2185 _Sentinel(_Sentinel<!_Const> __s)
2186 requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
2187 : _M_end(__s._M_end), _M_pred(__s._M_pred)
2190 constexpr sentinel_t<_Base>
2191 base()
const {
return _M_end; }
2193 friend constexpr
bool
2194 operator==(
const iterator_t<_Base>& __x,
const _Sentinel& __y)
2195 {
return __y._M_end == __x || !
std::__invoke(*__y._M_pred, *__x); }
2197 template<
bool _OtherConst = !_Const,
2198 typename _Base2 = __detail::__maybe_const_t<_OtherConst, _Vp>>
2199 requires sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
2200 friend constexpr
bool
2201 operator==(
const iterator_t<_Base2>& __x,
const _Sentinel& __y)
2202 {
return __y._M_end == __x || !
std::__invoke(*__y._M_pred, *__x); }
2204 friend _Sentinel<!_Const>;
2207 _Vp _M_base = _Vp();
2208 __detail::__box<_Pred> _M_pred;
2211 take_while_view() =
default;
2214 take_while_view(_Vp base, _Pred __pred)
2220 base() const& requires copy_constructible<_Vp>
2227 constexpr
const _Pred&
2229 {
return *_M_pred; }
2232 begin() requires (!__detail::__simple_view<_Vp>)
2236 begin() const requires range<const _Vp>
2237 && indirect_unary_predicate<const _Pred, iterator_t<const _Vp>>
2241 end() requires (!__detail::__simple_view<_Vp>)
2246 end() const requires range<const _Vp>
2247 && indirect_unary_predicate<const _Pred, iterator_t<const _Vp>>
2252 template<
typename _Range,
typename _Pred>
2253 take_while_view(_Range&&, _Pred)
2254 -> take_while_view<views::all_t<_Range>, _Pred>;
2258 inline constexpr __adaptor::_RangeAdaptor take_while
2259 = [] <viewable_range _Range,
typename _Pred> (_Range&& __r, _Pred&& __p)
2261 return take_while_view{std::forward<_Range>(__r), std::forward<_Pred>(__p)};
2266 class drop_view :
public view_interface<drop_view<_Vp>>
2269 _Vp _M_base = _Vp();
2270 range_difference_t<_Vp> _M_count = 0;
2274 static constexpr
bool _S_needs_cached_begin
2275 = !(random_access_range<const _Vp> && sized_range<const _Vp>);
2276 [[no_unique_address]]
2277 __detail::__maybe_present_t<_S_needs_cached_begin,
2278 __detail::_CachedPosition<_Vp>>
2282 drop_view() =
default;
2285 drop_view(_Vp
__base, range_difference_t<_Vp> __count)
2287 { __glibcxx_assert(__count >= 0); }
2290 base() const& requires copy_constructible<_Vp>
2300 requires (!(__detail::__simple_view<_Vp>
2301 && random_access_range<const _Vp>
2302 && sized_range<const _Vp>))
2304 if constexpr (_S_needs_cached_begin)
2305 if (_M_cached_begin._M_has_value())
2306 return _M_cached_begin._M_get(_M_base);
2310 if constexpr (_S_needs_cached_begin)
2311 _M_cached_begin._M_set(_M_base, __it);
2319 requires random_access_range<const _Vp> && sized_range<const _Vp>
2326 end() requires (!__detail::__simple_view<_Vp>)
2330 end() const requires range<const _Vp>
2334 size() requires sized_range<_Vp>
2336 const auto __s = ranges::size(_M_base);
2337 const auto __c =
static_cast<decltype(__s)
>(_M_count);
2338 return __s < __c ? 0 : __s - __c;
2342 size() const requires sized_range<const _Vp>
2344 const auto __s = ranges::size(_M_base);
2345 const auto __c =
static_cast<decltype(__s)
>(_M_count);
2346 return __s < __c ? 0 : __s - __c;
2350 template<
typename _Range>
2351 drop_view(_Range&&, range_difference_t<_Range>)
2352 -> drop_view<views::all_t<_Range>>;
2354 template<
typename _Tp>
2355 inline constexpr
bool enable_borrowed_range<drop_view<_Tp>>
2356 = enable_borrowed_range<_Tp>;
2360 inline constexpr __adaptor::_RangeAdaptor drop
2361 = [] <viewable_range _Range,
typename _Tp> (_Range&& __r, _Tp&& __n)
2363 return drop_view{std::forward<_Range>(__r), std::forward<_Tp>(__n)};
2367 template<view _Vp,
typename _Pred>
2368 requires input_range<_Vp> && is_object_v<_Pred>
2369 && indirect_unary_predicate<const _Pred, iterator_t<_Vp>>
2370 class drop_while_view :
public view_interface<drop_while_view<_Vp, _Pred>>
2373 _Vp _M_base = _Vp();
2374 __detail::__box<_Pred> _M_pred;
2375 [[no_unique_address]] __detail::_CachedPosition<_Vp> _M_cached_begin;
2378 drop_while_view() =
default;
2381 drop_while_view(_Vp
__base, _Pred __pred)
2386 base() const& requires copy_constructible<_Vp>
2393 constexpr
const _Pred&
2395 {
return *_M_pred; }
2400 if (_M_cached_begin._M_has_value())
2401 return _M_cached_begin._M_get(_M_base);
2405 std::cref(*_M_pred));
2406 _M_cached_begin._M_set(_M_base, __it);
2415 template<
typename _Range,
typename _Pred>
2416 drop_while_view(_Range&&, _Pred)
2417 -> drop_while_view<views::all_t<_Range>, _Pred>;
2419 template<
typename _Tp,
typename _Pred>
2420 inline constexpr
bool enable_borrowed_range<drop_while_view<_Tp, _Pred>>
2421 = enable_borrowed_range<_Tp>;
2425 inline constexpr __adaptor::_RangeAdaptor drop_while
2426 = [] <viewable_range _Range,
typename _Pred> (_Range&& __r, _Pred&& __p)
2428 return drop_while_view{std::forward<_Range>(__r),
2429 std::forward<_Pred>(__p)};
2433 template<input_range _Vp>
2434 requires view<_Vp> && input_range<range_reference_t<_Vp>>
2435 && (is_reference_v<range_reference_t<_Vp>>
2436 || view<range_value_t<_Vp>>)
2437 class join_view :
public view_interface<join_view<_Vp>>
2440 using _InnerRange = range_reference_t<_Vp>;
2442 template<
bool _Const>
2443 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2445 template<
bool _Const>
2446 using _Outer_iter = iterator_t<_Base<_Const>>;
2448 template<
bool _Const>
2449 using _Inner_iter = iterator_t<range_reference_t<_Base<_Const>>>;
2451 template<
bool _Const>
2452 static constexpr
bool _S_ref_is_glvalue
2453 = is_reference_v<range_reference_t<_Base<_Const>>>;
2455 template<
bool _Const>
2459 template<
bool _Const>
2460 requires _S_ref_is_glvalue<_Const>
2461 && forward_range<_Base<_Const>>
2462 && forward_range<range_reference_t<_Base<_Const>>>
2463 struct __iter_cat<_Const>
2466 static constexpr
auto
2469 using _Outer_iter = join_view::_Outer_iter<_Const>;
2470 using _Inner_iter = join_view::_Inner_iter<_Const>;
2471 using _OuterCat =
typename iterator_traits<_Outer_iter>::iterator_category;
2472 using _InnerCat =
typename iterator_traits<_Inner_iter>::iterator_category;
2473 if constexpr (derived_from<_OuterCat, bidirectional_iterator_tag>
2474 && derived_from<_InnerCat, bidirectional_iterator_tag>)
2475 return bidirectional_iterator_tag{};
2476 else if constexpr (derived_from<_OuterCat, forward_iterator_tag>
2477 && derived_from<_InnerCat, forward_iterator_tag>)
2478 return forward_iterator_tag{};
2480 return input_iterator_tag{};
2483 using iterator_category = decltype(_S_iter_cat());
2486 template<
bool _Const>
2489 template<
bool _Const>
2490 struct _Iterator : __iter_cat<_Const>
2493 using _Parent = __detail::__maybe_const_t<_Const, join_view>;
2494 using _Base = join_view::_Base<_Const>;
2496 static constexpr
bool _S_ref_is_glvalue
2497 = join_view::_S_ref_is_glvalue<_Const>;
2502 auto __update_inner = [
this] (range_reference_t<_Base> __x) ->
auto&
2504 if constexpr (_S_ref_is_glvalue)
2507 return (_M_parent->_M_inner = views::all(
std::move(__x)));
2510 for (; _M_outer !=
ranges::end(_M_parent->_M_base); ++_M_outer)
2512 auto& __inner = __update_inner(*_M_outer);
2518 if constexpr (_S_ref_is_glvalue)
2519 _M_inner = _Inner_iter();
2522 static constexpr
auto
2525 if constexpr (_S_ref_is_glvalue
2526 && bidirectional_range<_Base>
2527 && bidirectional_range<range_reference_t<_Base>>)
2528 return bidirectional_iterator_tag{};
2529 else if constexpr (_S_ref_is_glvalue
2530 && forward_range<_Base>
2531 && forward_range<range_reference_t<_Base>>)
2532 return forward_iterator_tag{};
2534 return input_iterator_tag{};
2537 using _Outer_iter = join_view::_Outer_iter<_Const>;
2538 using _Inner_iter = join_view::_Inner_iter<_Const>;
2540 _Outer_iter _M_outer = _Outer_iter();
2541 _Inner_iter _M_inner = _Inner_iter();
2542 _Parent* _M_parent =
nullptr;
2545 using iterator_concept = decltype(_S_iter_concept());
2547 using value_type = range_value_t<range_reference_t<_Base>>;
2548 using difference_type
2549 = common_type_t<range_difference_t<_Base>,
2550 range_difference_t<range_reference_t<_Base>>>;
2552 _Iterator() =
default;
2555 _Iterator(_Parent* __parent, _Outer_iter __outer)
2556 : _M_outer(
std::
move(__outer)),
2561 _Iterator(_Iterator<!_Const> __i)
2563 && convertible_to<iterator_t<_Vp>, _Outer_iter>
2564 && convertible_to<iterator_t<_InnerRange>, _Inner_iter>
2565 : _M_outer(
std::move(__i._M_outer)), _M_inner(__i._M_inner),
2566 _M_parent(__i._M_parent)
2569 constexpr decltype(
auto)
2571 {
return *_M_inner; }
2575 constexpr _Inner_iter
2577 requires __detail::__has_arrow<_Inner_iter>
2578 && copyable<_Inner_iter>
2579 {
return _M_inner; }
2581 constexpr _Iterator&
2584 auto&& __inner_range = [
this] () ->
auto&& {
2585 if constexpr (_S_ref_is_glvalue)
2588 return _M_parent->_M_inner;
2604 requires _S_ref_is_glvalue && forward_range<_Base>
2605 && forward_range<range_reference_t<_Base>>
2612 constexpr _Iterator&
2614 requires _S_ref_is_glvalue && bidirectional_range<_Base>
2615 && bidirectional_range<range_reference_t<_Base>>
2616 && common_range<range_reference_t<_Base>>
2628 requires _S_ref_is_glvalue && bidirectional_range<_Base>
2629 && bidirectional_range<range_reference_t<_Base>>
2630 && common_range<range_reference_t<_Base>>
2637 friend constexpr
bool
2638 operator==(
const _Iterator& __x,
const _Iterator& __y)
2639 requires _S_ref_is_glvalue
2640 && equality_comparable<_Outer_iter>
2641 && equality_comparable<_Inner_iter>
2643 return (__x._M_outer == __y._M_outer
2644 && __x._M_inner == __y._M_inner);
2647 friend constexpr decltype(
auto)
2648 iter_move(const _Iterator& __i)
2649 noexcept(noexcept(ranges::iter_move(__i._M_inner)))
2650 {
return ranges::iter_move(__i._M_inner); }
2652 friend constexpr
void
2653 iter_swap(
const _Iterator& __x,
const _Iterator& __y)
2654 noexcept(noexcept(ranges::iter_swap(__x._M_inner, __y._M_inner)))
2655 requires indirectly_swappable<_Inner_iter>
2656 {
return ranges::iter_swap(__x._M_inner, __y._M_inner); }
2658 friend _Iterator<!_Const>;
2659 template<
bool>
friend struct _Sentinel;
2662 template<
bool _Const>
2666 using _Parent = __detail::__maybe_const_t<_Const, join_view>;
2667 using _Base = join_view::_Base<_Const>;
2669 template<
bool _Const2>
2671 __equal(
const _Iterator<_Const2>& __i)
const
2672 {
return __i._M_outer == _M_end; }
2674 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
2677 _Sentinel() =
default;
2680 _Sentinel(_Parent* __parent)
2681 : _M_end(ranges::
end(__parent->_M_base))
2685 _Sentinel(_Sentinel<!_Const> __s)
2686 requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
2690 template<
bool _Const2>
2691 requires sentinel_for<sentinel_t<_Base>,
2692 iterator_t<__detail::__maybe_const_t<_Const2, _Vp>>>
2693 friend constexpr
bool
2694 operator==(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
2695 {
return __y.__equal(__x); }
2697 friend _Sentinel<!_Const>;
2700 _Vp _M_base = _Vp();
2703 [[no_unique_address]]
2704 __detail::__maybe_present_t<!is_reference_v<_InnerRange>,
2705 views::all_t<_InnerRange>> _M_inner;
2708 join_view() =
default;
2716 base() const& requires copy_constructible<_Vp>
2726 constexpr
bool __use_const
2727 = (__detail::__simple_view<_Vp>
2728 && is_reference_v<range_reference_t<_Vp>>);
2729 return _Iterator<__use_const>{
this,
ranges::begin(_M_base)};
2734 requires input_range<const _Vp>
2735 && is_reference_v<range_reference_t<const _Vp>>
2743 if constexpr (forward_range<_Vp> && is_reference_v<_InnerRange>
2744 && forward_range<_InnerRange>
2745 && common_range<_Vp> && common_range<_InnerRange>)
2746 return _Iterator<__detail::__simple_view<_Vp>>{
this,
2749 return _Sentinel<__detail::__simple_view<_Vp>>{
this};
2754 requires input_range<const _Vp>
2755 && is_reference_v<range_reference_t<const _Vp>>
2757 if constexpr (forward_range<const _Vp>
2758 && is_reference_v<range_reference_t<const _Vp>>
2759 && forward_range<range_reference_t<const _Vp>>
2760 && common_range<const _Vp>
2761 && common_range<range_reference_t<const _Vp>>)
2762 return _Iterator<true>{
this,
ranges::end(_M_base)};
2764 return _Sentinel<true>{
this};
2768 template<
typename _Range>
2769 explicit join_view(_Range&&) -> join_view<views::all_t<_Range>>;
2773 inline constexpr __adaptor::_RangeAdaptorClosure join
2774 = [] <viewable_range _Range> (_Range&& __r)
2778 return join_view<views::all_t<_Range>>{std::forward<_Range>(__r)};
2785 struct __require_constant;
2787 template<
typename _Range>
2788 concept __tiny_range = sized_range<_Range>
2790 {
typename __require_constant<remove_reference_t<_Range>::size()>; }
2791 && (remove_reference_t<_Range>::size() <= 1);
2793 template<
typename _Base>
2794 struct __split_view_outer_iter_cat
2797 template<forward_range _Base>
2798 struct __split_view_outer_iter_cat<_Base>
2799 {
using iterator_category = input_iterator_tag; };
2801 template<
typename _Base>
2802 struct __split_view_inner_iter_cat
2805 template<forward_range _Base>
2806 struct __split_view_inner_iter_cat<_Base>
2809 static constexpr
auto
2812 using _Cat =
typename iterator_traits<iterator_t<_Base>>::iterator_category;
2813 if constexpr (derived_from<_Cat, forward_iterator_tag>)
2814 return forward_iterator_tag{};
2819 using iterator_category = decltype(_S_iter_cat());
2823 template<input_range _Vp, forward_range _Pattern>
2824 requires view<_Vp> && view<_Pattern>
2825 && indirectly_comparable<iterator_t<_Vp>, iterator_t<_Pattern>,
2827 && (forward_range<_Vp> || __detail::__tiny_range<_Pattern>)
2828 class split_view :
public view_interface<split_view<_Vp, _Pattern>>
2831 template<
bool _Const>
2832 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2834 template<
bool _Const>
2837 template<
bool _Const>
2839 : __detail::__split_view_outer_iter_cat<_Base<_Const>>
2842 using _Parent = __detail::__maybe_const_t<_Const, split_view>;
2843 using _Base = split_view::_Base<_Const>;
2847 {
return __current() ==
ranges::end(_M_parent->_M_base); }
2854 __current() noexcept
2856 if constexpr (forward_range<_Vp>)
2859 return _M_parent->_M_current;
2863 __current() const noexcept
2865 if constexpr (forward_range<_Vp>)
2868 return _M_parent->_M_current;
2871 _Parent* _M_parent =
nullptr;
2874 [[no_unique_address]]
2875 __detail::__maybe_present_t<forward_range<_Vp>,
2876 iterator_t<_Base>> _M_current;
2879 using iterator_concept = conditional_t<forward_range<_Base>,
2880 forward_iterator_tag,
2881 input_iterator_tag>;
2883 using difference_type = range_difference_t<_Base>;
2885 struct value_type : view_interface<value_type>
2888 _OuterIter _M_i = _OuterIter();
2891 value_type() =
default;
2894 value_type(_OuterIter __i)
2898 constexpr _InnerIter<_Const>
2900 requires copyable<_OuterIter>
2901 {
return _InnerIter<_Const>{_M_i}; }
2903 constexpr _InnerIter<_Const>
2905 requires (!copyable<_OuterIter>)
2906 {
return _InnerIter<_Const>{
std::move(_M_i)}; }
2908 constexpr default_sentinel_t
2910 {
return default_sentinel; }
2913 _OuterIter() =
default;
2916 _OuterIter(_Parent* __parent) requires (!forward_range<_Base>)
2917 : _M_parent(__parent)
2921 _OuterIter(_Parent* __parent, iterator_t<_Base> __current)
2922 requires forward_range<_Base>
2923 : _M_parent(__parent),
2928 _OuterIter(_OuterIter<!_Const> __i)
2930 && convertible_to<iterator_t<_Vp>, iterator_t<_Base>>
2931 : _M_parent(__i._M_parent), _M_current(
std::move(__i._M_current))
2934 constexpr value_type
2936 {
return value_type{*
this}; }
2938 constexpr _OuterIter&
2943 const auto __end =
ranges::end(_M_parent->_M_base);
2944 if (__current() == __end)
2946 const auto [__pbegin, __pend] = subrange{_M_parent->_M_pattern};
2947 if (__pbegin == __pend)
2949 else if constexpr (__detail::__tiny_range<_Pattern>)
2951 __current() = __detail::find(
std::move(__current()), __end,
2953 if (__current() != __end)
2960 = __detail::mismatch(__current(), __end, __pbegin, __pend);
2966 }
while (++__current() != __end);
2970 constexpr decltype(
auto)
2973 if constexpr (forward_range<_Base>)
2983 friend constexpr
bool
2984 operator==(
const _OuterIter& __x,
const _OuterIter& __y)
2985 requires forward_range<_Base>
2986 {
return __x._M_current == __y._M_current; }
2988 friend constexpr
bool
2989 operator==(
const _OuterIter& __x, default_sentinel_t)
2990 {
return __x.__at_end(); };
2992 friend _OuterIter<!_Const>;
2993 friend _InnerIter<_Const>;
2996 template<
bool _Const>
2998 : __detail::__split_view_inner_iter_cat<_Base<_Const>>
3001 using _Base = split_view::_Base<_Const>;
3006 auto [__pcur, __pend] = subrange{_M_i._M_parent->_M_pattern};
3007 auto __end =
ranges::end(_M_i._M_parent->_M_base);
3008 if constexpr (__detail::__tiny_range<_Pattern>)
3010 const auto& __cur = _M_i_current();
3013 if (__pcur == __pend)
3014 return _M_incremented;
3015 return *__cur == *__pcur;
3019 auto __cur = _M_i_current();
3022 if (__pcur == __pend)
3023 return _M_incremented;
3026 if (*__cur != *__pcur)
3028 if (++__pcur == __pend)
3030 }
while (++__cur != __end);
3036 _M_i_current() noexcept
3037 {
return _M_i.__current(); }
3040 _M_i_current() const noexcept
3041 {
return _M_i.__current(); }
3043 _OuterIter<_Const> _M_i = _OuterIter<_Const>();
3044 bool _M_incremented =
false;
3047 using iterator_concept
3048 =
typename _OuterIter<_Const>::iterator_concept;
3050 using value_type = range_value_t<_Base>;
3051 using difference_type = range_difference_t<_Base>;
3053 _InnerIter() =
default;
3056 _InnerIter(_OuterIter<_Const> __i)
3060 constexpr decltype(
auto)
3062 {
return *_M_i_current(); }
3064 constexpr _InnerIter&
3067 _M_incremented =
true;
3068 if constexpr (!forward_range<_Base>)
3069 if constexpr (_Pattern::size() == 0)
3075 constexpr decltype(auto)
3078 if constexpr (forward_range<_Base>)
3088 friend constexpr
bool
3089 operator==(
const _InnerIter& __x,
const _InnerIter& __y)
3090 requires forward_range<_Base>
3091 {
return __x._M_i == __y._M_i; }
3093 friend constexpr
bool
3094 operator==(
const _InnerIter& __x, default_sentinel_t)
3095 {
return __x.__at_end(); }
3097 friend constexpr decltype(
auto)
3098 iter_move(const _InnerIter& __i)
3099 noexcept(noexcept(ranges::iter_move(__i._M_i_current())))
3100 {
return ranges::iter_move(__i._M_i_current()); }
3102 friend constexpr
void
3103 iter_swap(
const _InnerIter& __x,
const _InnerIter& __y)
3104 noexcept(noexcept(ranges::iter_swap(__x._M_i_current(),
3105 __y._M_i_current())))
3106 requires indirectly_swappable<iterator_t<_Base>>
3107 { ranges::iter_swap(__x._M_i_current(), __y._M_i_current()); }
3110 _Vp _M_base = _Vp();
3111 _Pattern _M_pattern = _Pattern();
3114 [[no_unique_address]]
3115 __detail::__maybe_present_t<!forward_range<_Vp>, iterator_t<_Vp>>
3120 split_view() =
default;
3123 split_view(_Vp
__base, _Pattern __pattern)
3127 template<input_range _Range>
3128 requires constructible_from<_Vp, views::all_t<_Range>>
3129 && constructible_from<_Pattern, single_view<range_value_t<_Range>>>
3131 split_view(_Range&& __r, range_value_t<_Range> __e)
3132 : _M_base(views::all(
std::
forward<_Range>(__r))),
3137 base() const& requires copy_constructible<_Vp>
3147 if constexpr (forward_range<_Vp>)
3148 return _OuterIter<__detail::__simple_view<_Vp>>{
3153 return _OuterIter<false>{
this};
3158 begin() const requires forward_range<_Vp> && forward_range<const _Vp>
3164 end() requires forward_range<_Vp> && common_range<_Vp>
3166 return _OuterIter<__detail::__simple_view<_Vp>>{
3173 if constexpr (forward_range<_Vp>
3174 && forward_range<const _Vp>
3175 && common_range<const _Vp>)
3176 return _OuterIter<true>{
this,
ranges::end(_M_base)};
3178 return default_sentinel;
3182 template<
typename _Range,
typename _Pred>
3183 split_view(_Range&&, _Pred&&)
3184 -> split_view<views::all_t<_Range>, views::all_t<_Pred>>;
3186 template<input_range _Range>
3187 split_view(_Range&&, range_value_t<_Range>)
3188 -> split_view<views::all_t<_Range>, single_view<range_value_t<_Range>>>;
3192 inline constexpr __adaptor::_RangeAdaptor split
3193 = [] <viewable_range _Range,
typename _Fp> (_Range&& __r, _Fp&& __f)
3195 return split_view{std::forward<_Range>(__r), std::forward<_Fp>(__f)};
3203 template<input_or_output_iterator _Iter>
3205 operator()(_Iter __i, iter_difference_t<_Iter> __n)
const
3207 if constexpr (random_access_iterator<_Iter>)
3208 return subrange{__i, __i + __n};
3210 return subrange{counted_iterator{
std::move(__i), __n},
3215 inline constexpr _Counted counted{};
3219 requires (!common_range<_Vp>) && copyable<iterator_t<_Vp>>
3220 class common_view :
public view_interface<common_view<_Vp>>
3223 _Vp _M_base = _Vp();
3226 common_view() =
default;
3229 common_view(_Vp __r)
3244 base() const& requires copy_constructible<_Vp>
3254 if constexpr (random_access_range<_Vp> && sized_range<_Vp>)
3257 return common_iterator<iterator_t<_Vp>, sentinel_t<_Vp>>
3262 begin() const requires range<const _Vp>
3264 if constexpr (random_access_range<const _Vp> && sized_range<const _Vp>)
3267 return common_iterator<iterator_t<const _Vp>, sentinel_t<const _Vp>>
3274 if constexpr (random_access_range<_Vp> && sized_range<_Vp>)
3277 return common_iterator<iterator_t<_Vp>, sentinel_t<_Vp>>
3282 end() const requires range<const _Vp>
3284 if constexpr (random_access_range<const _Vp> && sized_range<const _Vp>)
3287 return common_iterator<iterator_t<const _Vp>, sentinel_t<const _Vp>>
3292 size() requires sized_range<_Vp>
3293 {
return ranges::size(_M_base); }
3296 size() const requires sized_range<const _Vp>
3297 {
return ranges::size(_M_base); }
3300 template<
typename _Range>
3301 common_view(_Range&&) -> common_view<views::all_t<_Range>>;
3303 template<
typename _Tp>
3304 inline constexpr
bool enable_borrowed_range<common_view<_Tp>>
3305 = enable_borrowed_range<_Tp>;
3309 inline constexpr __adaptor::_RangeAdaptorClosure common
3310 = [] <viewable_range _Range> (_Range&& __r)
3312 if constexpr (common_range<_Range>
3313 && requires { views::all(std::forward<_Range>(__r)); })
3314 return views::all(std::forward<_Range>(__r));
3316 return common_view{std::forward<_Range>(__r)};
3322 requires bidirectional_range<_Vp>
3323 class reverse_view :
public view_interface<reverse_view<_Vp>>
3326 _Vp _M_base = _Vp();
3328 static constexpr
bool _S_needs_cached_begin
3329 = !common_range<_Vp> && !random_access_range<_Vp>;
3330 [[no_unique_address]]
3331 __detail::__maybe_present_t<_S_needs_cached_begin,
3332 __detail::_CachedPosition<_Vp>>
3336 reverse_view() =
default;
3339 reverse_view(_Vp __r)
3344 base() const& requires copy_constructible<_Vp>
3351 constexpr reverse_iterator<iterator_t<_Vp>>
3354 if constexpr (_S_needs_cached_begin)
3355 if (_M_cached_begin._M_has_value())
3359 if constexpr (_S_needs_cached_begin)
3360 _M_cached_begin._M_set(_M_base, __it);
3365 begin() requires common_range<_Vp>
3369 begin() const requires common_range<const _Vp>
3372 constexpr reverse_iterator<iterator_t<_Vp>>
3377 end() const requires common_range<const _Vp>
3381 size() requires sized_range<_Vp>
3382 {
return ranges::size(_M_base); }
3385 size() const requires sized_range<const _Vp>
3386 {
return ranges::size(_M_base); }
3389 template<
typename _Range>
3390 reverse_view(_Range&&) -> reverse_view<views::all_t<_Range>>;
3392 template<
typename _Tp>
3393 inline constexpr
bool enable_borrowed_range<reverse_view<_Tp>>
3394 = enable_borrowed_range<_Tp>;
3401 inline constexpr
bool __is_reversible_subrange =
false;
3403 template<
typename _Iter, subrange_kind _Kind>
3404 inline constexpr
bool
3405 __is_reversible_subrange<subrange<reverse_iterator<_Iter>,
3406 reverse_iterator<_Iter>,
3410 inline constexpr
bool __is_reverse_view =
false;
3412 template<
typename _Vp>
3413 inline constexpr
bool __is_reverse_view<reverse_view<_Vp>> =
true;
3416 inline constexpr __adaptor::_RangeAdaptorClosure reverse
3417 = [] <viewable_range _Range> (_Range&& __r)
3419 using _Tp = remove_cvref_t<_Range>;
3420 if constexpr (__detail::__is_reverse_view<_Tp>)
3421 return std::forward<_Range>(__r).base();
3422 else if constexpr (__detail::__is_reversible_subrange<_Tp>)
3425 if constexpr (sized_range<_Tp>)
3426 return subrange<_Iter, _Iter, subrange_kind::sized>
3427 (__r.end().base(), __r.begin().base(), __r.size());
3429 return subrange<_Iter, _Iter, subrange_kind::unsized>
3430 (__r.end().base(), __r.begin().base());
3433 return reverse_view{std::forward<_Range>(__r)};
3439 template<
typename _Tp,
size_t _Nm>
3440 concept __has_tuple_element = requires(_Tp __t)
3442 typename tuple_size<_Tp>::type;
3443 requires _Nm < tuple_size_v<_Tp>;
3444 typename tuple_element_t<_Nm, _Tp>;
3445 { std::get<_Nm>(__t) }
3446 -> convertible_to<const tuple_element_t<_Nm, _Tp>&>;
3449 template<
typename _Tp,
size_t _Nm>
3450 concept __returnable_element
3451 = is_reference_v<_Tp> || move_constructible<tuple_element_t<_Nm, _Tp>>;
3454 template<input_range _Vp,
size_t _Nm>
3456 && __detail::__has_tuple_element<range_value_t<_Vp>, _Nm>
3457 && __detail::__has_tuple_element<remove_reference_t<range_reference_t<_Vp>>,
3459 && __detail::__returnable_element<range_reference_t<_Vp>, _Nm>
3460 class elements_view :
public view_interface<elements_view<_Vp, _Nm>>
3463 elements_view() =
default;
3466 elements_view(_Vp base)
3471 base() const& requires copy_constructible<_Vp>
3479 begin() requires (!__detail::__simple_view<_Vp>)
3483 begin() const requires range<const _Vp>
3487 end() requires (!__detail::__simple_view<_Vp> && !common_range<_Vp>)
3488 {
return _Sentinel<false>{
ranges::end(_M_base)}; }
3491 end() requires (!__detail::__simple_view<_Vp> && common_range<_Vp>)
3492 {
return _Iterator<false>{
ranges::end(_M_base)}; }
3495 end() const requires range<const _Vp>
3499 end() const requires common_range<const _Vp>
3503 size() requires sized_range<_Vp>
3504 {
return ranges::size(_M_base); }
3507 size() const requires sized_range<const _Vp>
3508 {
return ranges::size(_M_base); }
3511 template<
bool _Const>
3512 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
3514 template<
bool _Const>
3518 template<
bool _Const>
3519 requires forward_range<_Base<_Const>>
3520 struct __iter_cat<_Const>
3523 static auto _S_iter_cat()
3525 using _Base = elements_view::_Base<_Const>;
3526 using _Cat = iterator_traits<iterator_t<_Base>>::iterator_category;
3527 using _Res = decltype((std::get<_Nm>(*std::declval<iterator_t<_Base>>())));
3528 if constexpr (!is_lvalue_reference_v<_Res>)
3529 return input_iterator_tag{};
3530 else if constexpr (derived_from<_Cat, random_access_iterator_tag>)
3531 return random_access_iterator_tag{};
3536 using iterator_category = decltype(_S_iter_cat());
3539 template<
bool _Const>
3542 template<
bool _Const>
3543 struct _Iterator : __iter_cat<_Const>
3546 using _Base = elements_view::_Base<_Const>;
3548 iterator_t<_Base> _M_current = iterator_t<_Base>();
3550 static constexpr decltype(
auto)
3551 _S_get_element(const iterator_t<_Base>& __i)
3553 if constexpr (is_reference_v<range_reference_t<_Base>>)
3554 return
std::get<_Nm>(*__i);
3557 using _Et = remove_cv_t<tuple_element_t<_Nm, range_reference_t<_Base>>>;
3558 return static_cast<_Et
>(std::get<_Nm>(*__i));
3565 if constexpr (random_access_range<_Vp>)
3566 return random_access_iterator_tag{};
3567 else if constexpr (bidirectional_range<_Vp>)
3568 return bidirectional_iterator_tag{};
3569 else if constexpr (forward_range<_Vp>)
3570 return forward_iterator_tag{};
3572 return input_iterator_tag{};
3575 friend _Iterator<!_Const>;
3578 using iterator_concept = decltype(_S_iter_concept());
3581 = remove_cvref_t<tuple_element_t<_Nm, range_value_t<_Base>>>;
3582 using difference_type = range_difference_t<_Base>;
3584 _Iterator() =
default;
3587 _Iterator(iterator_t<_Base> current)
3588 : _M_current(
std::
move(current))
3592 _Iterator(_Iterator<!_Const> i)
3593 requires _Const && convertible_to<iterator_t<_Vp>, iterator_t<_Base>>
3597 constexpr iterator_t<_Base>
3599 requires copyable<iterator_t<_Base>>
3600 {
return _M_current; }
3602 constexpr iterator_t<_Base>
3606 constexpr decltype(
auto)
3608 {
return _S_get_element(_M_current); }
3610 constexpr _Iterator&
3622 operator++(
int) requires forward_range<_Base>
3629 constexpr _Iterator&
3630 operator--() requires bidirectional_range<_Base>
3637 operator--(
int) requires bidirectional_range<_Base>
3644 constexpr _Iterator&
3645 operator+=(difference_type __n)
3646 requires random_access_range<_Base>
3652 constexpr _Iterator&
3653 operator-=(difference_type __n)
3654 requires random_access_range<_Base>
3660 constexpr decltype(
auto)
3661 operator[](difference_type __n) const
3662 requires random_access_range<_Base>
3663 {
return _S_get_element(_M_current + __n); }
3665 friend constexpr
bool
3666 operator==(
const _Iterator& __x,
const _Iterator& __y)
3667 requires equality_comparable<iterator_t<_Base>>
3668 {
return __x._M_current == __y._M_current; }
3670 friend constexpr
bool
3671 operator<(
const _Iterator& __x,
const _Iterator& __y)
3672 requires random_access_range<_Base>
3673 {
return __x._M_current < __y._M_current; }
3675 friend constexpr
bool
3676 operator>(
const _Iterator& __x,
const _Iterator& __y)
3677 requires random_access_range<_Base>
3678 {
return __y._M_current < __x._M_current; }
3680 friend constexpr
bool
3681 operator<=(
const _Iterator& __x,
const _Iterator& __y)
3682 requires random_access_range<_Base>
3683 {
return !(__y._M_current > __x._M_current); }
3685 friend constexpr
bool
3686 operator>=(
const _Iterator& __x,
const _Iterator& __y)
3687 requires random_access_range<_Base>
3688 {
return !(__x._M_current > __y._M_current); }
3690 #ifdef __cpp_lib_three_way_comparison
3691 friend constexpr
auto
3692 operator<=>(
const _Iterator& __x,
const _Iterator& __y)
3693 requires random_access_range<_Base>
3694 && three_way_comparable<iterator_t<_Base>>
3695 {
return __x._M_current <=> __y._M_current; }
3698 friend constexpr _Iterator
3699 operator+(
const _Iterator& __x, difference_type __y)
3700 requires random_access_range<_Base>
3701 {
return _Iterator{__x} += __y; }
3703 friend constexpr _Iterator
3704 operator+(difference_type __x,
const _Iterator& __y)
3705 requires random_access_range<_Base>
3706 {
return __y + __x; }
3708 friend constexpr _Iterator
3709 operator-(
const _Iterator& __x, difference_type __y)
3710 requires random_access_range<_Base>
3711 {
return _Iterator{__x} -= __y; }
3715 friend constexpr difference_type
3716 operator-(
const _Iterator& __x,
const _Iterator& __y)
3717 requires sized_sentinel_for<iterator_t<_Base>, iterator_t<_Base>>
3718 {
return __x._M_current - __y._M_current; }
3720 friend _Sentinel<_Const>;
3723 template<
bool _Const>
3728 _M_equal(
const _Iterator<_Const>& __x)
const
3729 {
return __x._M_current == _M_end; }
3731 using _Base = elements_view::_Base<_Const>;
3732 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
3735 _Sentinel() =
default;
3738 _Sentinel(sentinel_t<_Base> __end)
3743 _Sentinel(_Sentinel<!_Const> __other)
3745 && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
3749 constexpr sentinel_t<_Base>
3753 template<
bool _Const2>
3754 requires sentinel_for<sentinel_t<_Base>,
3755 iterator_t<__detail::__maybe_const_t<_Const2, _Vp>>>
3756 friend constexpr
bool
3757 operator==(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
3758 {
return __y._M_equal(__x); }
3760 template<
bool _Const2,
3761 typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
3762 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
3763 friend constexpr range_difference_t<_Base2>
3764 operator-(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
3765 {
return __x._M_current - __y._M_end; }
3767 template<
bool _Const2,
3768 typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
3769 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
3770 friend constexpr range_difference_t<_Base>
3771 operator-(
const _Sentinel& __x,
const _Iterator<_Const2>& __y)
3772 {
return __x._M_end - __y._M_current; }
3774 friend _Sentinel<!_Const>;
3777 _Vp _M_base = _Vp();
3780 template<
typename _Tp,
size_t _Nm>
3781 inline constexpr
bool enable_borrowed_range<elements_view<_Tp, _Nm>>
3782 = enable_borrowed_range<_Tp>;
3784 template<
typename _Range>
3785 using keys_view = elements_view<views::all_t<_Range>, 0>;
3787 template<
typename _Range>
3788 using values_view = elements_view<views::all_t<_Range>, 1>;
3792 template<
size_t _Nm>
3793 inline constexpr __adaptor::_RangeAdaptorClosure elements
3794 = [] <viewable_range _Range> (_Range&& __r)
3796 using _El = elements_view<views::all_t<_Range>, _Nm>;
3797 return _El{std::forward<_Range>(__r)};
3800 inline constexpr __adaptor::_RangeAdaptorClosure keys = elements<0>;
3801 inline constexpr __adaptor::_RangeAdaptorClosure values = elements<1>;
3806 namespace views = ranges::views;
3808 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3809 struct tuple_size<ranges::subrange<_Iter, _Sent, _Kind>>
3810 : integral_constant<size_t, 2>
3813 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3814 struct tuple_element<0, ranges::subrange<_Iter, _Sent, _Kind>>
3815 {
using type = _Iter; };
3817 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3818 struct tuple_element<1, ranges::subrange<_Iter, _Sent, _Kind>>
3819 {
using type = _Sent; };
3821 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3822 struct tuple_element<0, const ranges::subrange<_Iter, _Sent, _Kind>>
3823 {
using type = _Iter; };
3825 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3826 struct tuple_element<1, const ranges::subrange<_Iter, _Sent, _Kind>>
3827 {
using type = _Sent; };
3829 _GLIBCXX_END_NAMESPACE_VERSION
constexpr complex< _Tp > operator*(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x times y.
constexpr complex< _Tp > operator-(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x minus y.
constexpr complex< _Tp > operator+(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x plus y.
typename make_unsigned< _Tp >::type make_unsigned_t
Alias template for make_unsigned.
typename remove_const< _Tp >::type remove_const_t
Alias template for remove_const.
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
constexpr __invoke_result< _Callable, _Args... >::type __invoke(_Callable &&__fn, _Args &&... __args) noexcept(__is_nothrow_invocable< _Callable, _Args... >::value)
Invoke a callable object.
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
_Tp * begin(valarray< _Tp > &__va)
Return an iterator pointing to the first element of the valarray.
_Tp * end(valarray< _Tp > &__va)
Return an iterator pointing to one past the last element of the valarray.
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
constexpr reverse_iterator< _Iterator > make_reverse_iterator(_Iterator __i)
Generator function for reverse_iterator.
constexpr void iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value)
Create a range of sequentially increasing values.
constexpr in_place_t in_place
Tag for in-place construction.
ISO C++ entities toplevel namespace is std.
constexpr iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
bitset< _Nb > operator|(const bitset< _Nb > &__x, const bitset< _Nb > &__y) noexcept
Global bitwise operations on bitsets.
constexpr void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
constexpr _Iterator __base(_Iterator __it)