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>>;
225 template<
typename _Tp>
226 concept __iterator_sentinel_pair
227 = !range<_Tp> && __pair_like<_Tp>
228 && sentinel_for<tuple_element_t<1, _Tp>, tuple_element_t<0, _Tp>>;
232 enum class subrange_kind : bool { unsized, sized };
234 template<input_or_output_iterator _It, sentinel_for<_It> _Sent = _It,
235 subrange_kind _Kind = sized_sentinel_for<_Sent, _It>
236 ? subrange_kind::sized : subrange_kind::unsized>
237 requires (_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _It>)
238 class subrange : public view_interface<subrange<_It, _Sent, _Kind>>
242 static const bool _S_store_size
243 = _Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _It>;
245 _It _M_begin = _It();
246 _Sent _M_end = _Sent();
248 template<
typename,
bool = _S_store_size>
252 template<
typename _Tp>
253 struct _Size<_Tp, true>
254 { __detail::__make_unsigned_like_t<_Tp> _M_size; };
256 [[no_unique_address]] _Size<iter_difference_t<_It>> _M_size = {};
259 subrange() =
default;
262 subrange(__detail::__convertible_to_non_slicing<_It>
auto __i, _Sent __s)
263 requires (!_S_store_size)
264 : _M_begin(std::
move(__i)), _M_end(__s)
268 subrange(__detail::__convertible_to_non_slicing<_It>
auto __i, _Sent __s,
269 __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n)
270 requires (_Kind == subrange_kind::sized)
271 : _M_begin(std::
move(__i)), _M_end(__s)
273 using __detail::__to_unsigned_like;
275 if constexpr (_S_store_size)
276 _M_size._M_size = __n;
279 template<__detail::__not_same_as<subrange> _Rng>
280 requires borrowed_range<_Rng>
281 && __detail::__convertible_to_non_slicing<iterator_t<_Rng>, _It>
282 && convertible_to<sentinel_t<_Rng>, _Sent>
284 subrange(_Rng&& __r) requires _S_store_size && sized_range<_Rng>
285 : subrange{__r, ranges::size(__r)}
288 template<__detail::__not_same_as<subrange> _Rng>
289 requires borrowed_range<_Rng>
290 && __detail::__convertible_to_non_slicing<iterator_t<_Rng>, _It>
291 && convertible_to<sentinel_t<_Rng>, _Sent>
293 subrange(_Rng&& __r) requires (!_S_store_size)
297 template<borrowed_range _Rng>
298 requires __detail::__convertible_to_non_slicing<iterator_t<_Rng>, _It>
299 && convertible_to<sentinel_t<_Rng>, _Sent>
302 __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n)
303 requires (_Kind == subrange_kind::sized)
307 template<__detail::__not_same_as<subrange> _PairLike>
308 requires __detail::__pair_like_convertible_from<_PairLike,
const _It&,
311 operator _PairLike()
const
312 {
return _PairLike(_M_begin, _M_end); }
315 begin() const requires copyable<_It>
318 [[nodiscard]] constexpr _It
319 begin() requires (!copyable<_It>)
322 constexpr _Sent
end()
const {
return _M_end; }
324 constexpr
bool empty()
const {
return _M_begin == _M_end; }
326 constexpr __detail::__make_unsigned_like_t<iter_difference_t<_It>>
327 size() const requires (_Kind == subrange_kind::sized)
329 if constexpr (_S_store_size)
330 return _M_size._M_size;
332 return __detail::__to_unsigned_like(_M_end - _M_begin);
335 [[nodiscard]] constexpr subrange
336 next(iter_difference_t<_It> __n = 1) const &
337 requires forward_iterator<_It>
344 [[nodiscard]] constexpr subrange
345 next(iter_difference_t<_It> __n = 1) &&
351 [[nodiscard]] constexpr subrange
352 prev(iter_difference_t<_It> __n = 1) const
353 requires bidirectional_iterator<_It>
361 advance(iter_difference_t<_It> __n)
365 if constexpr (bidirectional_iterator<_It>)
369 if constexpr (_S_store_size)
370 _M_size._M_size += __detail::__to_unsigned_like(-__n);
374 __glibcxx_assert(__n >= 0);
375 auto __d = __n - ranges::
advance(_M_begin, __n, _M_end);
376 if constexpr (_S_store_size)
377 _M_size._M_size -= __detail::__to_unsigned_like(__d);
382 template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
383 subrange(_It, _Sent) -> subrange<_It, _Sent>;
385 template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
387 __detail::__make_unsigned_like_t<iter_difference_t<_It>>)
388 -> subrange<_It, _Sent, subrange_kind::sized>;
390 template<__detail::__iterator_sentinel_pair _Pr>
392 -> subrange<tuple_element_t<0, _Pr>, tuple_element_t<1, _Pr>>;
394 template<__detail::__iterator_sentinel_pair _Pr>
395 subrange(_Pr, __detail::__make_unsigned_like_t<iter_difference_t<
396 tuple_element_t<0, _Pr>>>)
397 -> subrange<tuple_element_t<0, _Pr>, tuple_element_t<1, _Pr>,
398 subrange_kind::sized>;
400 template<borrowed_range _Rng>
402 -> subrange<iterator_t<_Rng>, sentinel_t<_Rng>,
404 || sized_sentinel_for<sentinel_t<_Rng>, iterator_t<_Rng>>)
405 ? subrange_kind::sized : subrange_kind::unsized>;
407 template<borrowed_range _Rng>
409 __detail::__make_unsigned_like_t<range_difference_t<_Rng>>)
410 -> subrange<iterator_t<_Rng>, sentinel_t<_Rng>, subrange_kind::sized>;
412 template<
size_t _Num, class _It, class _Sent, subrange_kind _Kind>
415 get(const subrange<_It, _Sent, _Kind>& __r)
417 if constexpr (_Num == 0)
423 template<
size_t _Num, class _It, class _Sent, subrange_kind _Kind>
426 get(subrange<_It, _Sent, _Kind>&& __r)
428 if constexpr (_Num == 0)
434 template<input_or_output_iterator _It, sentinel_for<_It> _Sent,
436 inline constexpr
bool
437 enable_borrowed_range<subrange<_It, _Sent, _Kind>> = true;
448 constexpr dangling() noexcept = default;
449 template<typename... _Args>
450 constexpr dangling(_Args&&...) noexcept { }
453 template<range _Range>
454 using borrowed_iterator_t = conditional_t<borrowed_range<_Range>,
458 template<range _Range>
459 using borrowed_subrange_t = conditional_t<borrowed_range<_Range>,
460 subrange<iterator_t<_Range>>,
463 template<
typename _Tp> requires is_object_v<_Tp>
465 :
public view_interface<empty_view<_Tp>>
468 static constexpr _Tp*
begin() noexcept {
return nullptr; }
469 static constexpr _Tp*
end() noexcept {
return nullptr; }
470 static constexpr _Tp* data() noexcept {
return nullptr; }
471 static constexpr
size_t size() noexcept {
return 0; }
472 static constexpr
bool empty() noexcept {
return true; }
475 template<
typename _Tp>
476 inline constexpr
bool enable_borrowed_range<empty_view<_Tp>> =
true;
480 template<copy_constructible _Tp> requires is_object_v<_Tp>
481 struct __box : std::optional<_Tp>
483 using std::optional<_Tp>::optional;
487 noexcept(is_nothrow_default_constructible_v<_Tp>)
488 requires default_initializable<_Tp>
492 __box(
const __box&) =
default;
493 __box(__box&&) =
default;
495 using std::optional<_Tp>::operator=;
498 operator=(
const __box& __that)
499 noexcept(is_nothrow_copy_constructible_v<_Tp>)
500 requires (!assignable_from<_Tp&, const _Tp&>)
503 this->emplace(*__that);
510 operator=(__box&& __that)
511 noexcept(is_nothrow_move_constructible_v<_Tp>)
512 requires (!assignable_from<_Tp&, _Tp>)
525 template<copy_constructible _Tp> requires is_object_v<_Tp>
526 class single_view :
public view_interface<single_view<_Tp>>
529 single_view() =
default;
532 single_view(
const _Tp& __t)
537 single_view(_Tp&& __t)
538 : _M_value(std::
move(__t))
543 template<
typename... _Args>
544 requires constructible_from<_Tp, _Args...>
546 single_view(in_place_t, _Args&&... __args)
547 : _M_value{
in_place, std::forward<_Args>(__args)...}
555 begin() const noexcept
560 {
return data() + 1; }
564 {
return data() + 1; }
566 static constexpr
size_t
572 {
return _M_value.operator->(); }
575 data() const noexcept
576 {
return _M_value.operator->(); }
579 __detail::__box<_Tp> _M_value;
584 template<
typename _Wp>
585 constexpr
auto __to_signed_like(_Wp __w) noexcept
587 if constexpr (!integral<_Wp>)
588 return iter_difference_t<_Wp>();
589 else if constexpr (sizeof(iter_difference_t<_Wp>) > sizeof(_Wp))
590 return iter_difference_t<_Wp>(__w);
591 else if constexpr (sizeof(ptrdiff_t) > sizeof(_Wp))
592 return ptrdiff_t(__w);
593 else if constexpr (sizeof(
long long) > sizeof(_Wp))
594 return (
long long)(__w);
595 #ifdef __SIZEOF_INT128__
596 else if constexpr (__SIZEOF_INT128__ >
sizeof(_Wp))
597 return __int128(__w);
600 return __max_diff_type(__w);
603 template<
typename _Wp>
604 using __iota_diff_t = decltype(__to_signed_like(std::declval<_Wp>()));
606 template<
typename _It>
607 concept __decrementable = incrementable<_It>
610 { --__i } -> same_as<_It&>;
611 { __i-- } -> same_as<_It>;
614 template<
typename _It>
615 concept __advanceable = __decrementable<_It> && totally_ordered<_It>
616 && requires( _It __i,
const _It __j,
const __iota_diff_t<_It> __n)
618 { __i += __n } -> same_as<_It&>;
619 { __i -= __n } -> same_as<_It&>;
623 { __j - __j } -> convertible_to<__iota_diff_t<_It>>;
628 template<weakly_incrementable _Winc,
629 semiregular _Bound = unreachable_sentinel_t>
630 requires std::__detail::__weakly_eq_cmp_with<_Winc, _Bound>
631 && semiregular<_Winc>
632 class iota_view :
public view_interface<iota_view<_Winc, _Bound>>
643 using namespace __detail;
644 if constexpr (__advanceable<_Winc>)
645 return random_access_iterator_tag{};
646 else if constexpr (__decrementable<_Winc>)
647 return bidirectional_iterator_tag{};
648 else if constexpr (incrementable<_Winc>)
649 return forward_iterator_tag{};
651 return input_iterator_tag{};
655 using iterator_category = decltype(_S_iter_cat());
656 using value_type = _Winc;
657 using difference_type = __detail::__iota_diff_t<_Winc>;
659 _Iterator() =
default;
662 _Iterator(_Winc __value)
663 : _M_value(__value) { }
666 operator*() const noexcept(is_nothrow_copy_constructible_v<_Winc>)
681 operator++(
int) requires incrementable<_Winc>
689 operator--() requires __detail::__decrementable<_Winc>
696 operator--(
int) requires __detail::__decrementable<_Winc>
704 operator+=(difference_type __n) requires __detail::__advanceable<_Winc>
706 using __detail::__is_integer_like;
707 using __detail::__is_signed_integer_like;
708 if constexpr (__is_integer_like<_Winc>
709 && !__is_signed_integer_like<_Winc>)
711 if (__n >= difference_type(0))
712 _M_value +=
static_cast<_Winc
>(__n);
714 _M_value -=
static_cast<_Winc
>(-__n);
722 operator-=(difference_type __n) requires __detail::__advanceable<_Winc>
724 using __detail::__is_integer_like;
725 using __detail::__is_signed_integer_like;
726 if constexpr (__is_integer_like<_Winc>
727 && !__is_signed_integer_like<_Winc>)
729 if (__n >= difference_type(0))
730 _M_value -=
static_cast<_Winc
>(__n);
732 _M_value +=
static_cast<_Winc
>(-__n);
740 operator[](difference_type __n)
const
741 requires __detail::__advanceable<_Winc>
742 {
return _Winc(_M_value + __n); }
744 friend constexpr
bool
745 operator==(
const _Iterator& __x,
const _Iterator& __y)
746 requires equality_comparable<_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 __x._M_value < __y._M_value; }
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 !(__y < __x); }
764 friend constexpr
bool
765 operator>=(
const _Iterator& __x,
const _Iterator& __y)
766 requires totally_ordered<_Winc>
767 {
return !(__x < __y); }
769 #ifdef __cpp_lib_three_way_comparison
770 friend constexpr
auto
771 operator<=>(
const _Iterator& __x,
const _Iterator& __y)
772 requires totally_ordered<_Winc> && three_way_comparable<_Winc>
773 {
return __x._M_value <=> __y._M_value; }
776 friend constexpr _Iterator
777 operator+(_Iterator __i, difference_type __n)
778 requires __detail::__advanceable<_Winc>
779 {
return __i += __n; }
781 friend constexpr _Iterator
782 operator+(difference_type __n, _Iterator __i)
783 requires __detail::__advanceable<_Winc>
784 {
return __i += __n; }
786 friend constexpr _Iterator
787 operator-(_Iterator __i, difference_type __n)
788 requires __detail::__advanceable<_Winc>
789 {
return __i -= __n; }
791 friend constexpr difference_type
792 operator-(
const _Iterator& __x,
const _Iterator& __y)
793 requires __detail::__advanceable<_Winc>
795 using __detail::__is_integer_like;
796 using __detail::__is_signed_integer_like;
797 using _Dt = difference_type;
798 if constexpr (__is_integer_like<_Winc>)
800 if constexpr (__is_signed_integer_like<_Winc>)
801 return _Dt(_Dt(__x._M_value) - _Dt(__y._M_value));
803 return (__y._M_value > __x._M_value)
804 ? _Dt(-_Dt(__y._M_value - __x._M_value))
805 : _Dt(__x._M_value - __y._M_value);
808 return __x._M_value - __y._M_value;
812 _Winc _M_value = _Winc();
821 _M_equal(
const _Iterator& __x)
const
822 {
return __x._M_value == _M_bound; }
824 _Bound _M_bound = _Bound();
827 _Sentinel() =
default;
830 _Sentinel(_Bound __bound)
831 : _M_bound(__bound) { }
833 friend constexpr
bool
834 operator==(
const _Iterator& __x,
const _Sentinel& __y)
835 {
return __y._M_equal(__x); }
837 friend constexpr iter_difference_t<_Winc>
838 operator-(
const _Iterator& __x,
const _Sentinel& __y)
839 requires sized_sentinel_for<_Bound, _Winc>
840 {
return __x._M_value - __y._M_bound; }
842 friend constexpr iter_difference_t<_Winc>
843 operator-(
const _Sentinel& __x,
const _Iterator& __y)
844 requires sized_sentinel_for<_Bound, _Winc>
845 {
return -(__y - __x); }
848 _Winc _M_value = _Winc();
849 _Bound _M_bound = _Bound();
852 iota_view() =
default;
855 iota_view(_Winc __value)
860 iota_view(type_identity_t<_Winc> __value,
861 type_identity_t<_Bound> __bound)
862 : _M_value(__value), _M_bound(__bound)
864 if constexpr (totally_ordered_with<_Winc, _Bound>)
866 __glibcxx_assert(
bool(__value <= __bound) );
871 begin()
const {
return _Iterator{_M_value}; }
876 if constexpr (same_as<_Bound, unreachable_sentinel_t>)
877 return unreachable_sentinel;
879 return _Sentinel{_M_bound};
883 end() const requires same_as<_Winc, _Bound>
884 {
return _Iterator{_M_bound}; }
888 requires (same_as<_Winc, _Bound> && __detail::__advanceable<_Winc>)
889 || (integral<_Winc> && integral<_Bound>)
890 || sized_sentinel_for<_Bound, _Winc>
892 using __detail::__is_integer_like;
893 using __detail::__to_unsigned_like;
894 if constexpr (__is_integer_like<_Winc> && __is_integer_like<_Bound>)
895 return (_M_value < 0)
897 ? __to_unsigned_like(-_M_value) - __to_unsigned_like(-_M_bound)
898 : __to_unsigned_like(_M_bound) + __to_unsigned_like(-_M_value))
899 : __to_unsigned_like(_M_bound) - __to_unsigned_like(_M_value);
901 return __to_unsigned_like(_M_bound - _M_value);
905 template<typename _Winc, typename _Bound>
906 requires (!__detail::__is_integer_like<_Winc>
907 || !__detail::__is_integer_like<_Bound>
908 || (__detail::__is_signed_integer_like<_Winc>
909 == __detail::__is_signed_integer_like<_Bound>))
910 iota_view(_Winc, _Bound) -> iota_view<_Winc, _Bound>;
912 template<weakly_incrementable _Winc, semiregular _Bound>
913 inline constexpr
bool
914 enable_borrowed_range<iota_view<_Winc, _Bound>> = true;
918 template<
typename _Tp>
919 inline constexpr empty_view<_Tp> empty{};
923 template<
typename _Tp>
925 operator()(_Tp&& __e)
const
926 {
return single_view{std::forward<_Tp>(__e)}; }
929 inline constexpr _Single single{};
933 template<
typename _Tp>
935 operator()(_Tp&& __e)
const
936 {
return iota_view{std::forward<_Tp>(__e)}; }
938 template<
typename _Tp,
typename _Up>
940 operator()(_Tp&& __e, _Up&& __f)
const
941 {
return iota_view{std::forward<_Tp>(__e), std::forward<_Up>(__f)}; }
944 inline constexpr _Iota
iota{};
949 template<
typename _Val,
typename _CharT,
typename _Traits>
950 concept __stream_extractable
951 = requires(basic_istream<_CharT, _Traits>& is, _Val& t) { is >> t; };
954 template<movable _Val,
typename _CharT,
typename _Traits>
955 requires default_initializable<_Val>
956 && __detail::__stream_extractable<_Val, _CharT, _Traits>
957 class basic_istream_view
958 :
public view_interface<basic_istream_view<_Val, _CharT, _Traits>>
961 basic_istream_view() =
default;
964 basic_istream_view(basic_istream<_CharT, _Traits>& __stream)
971 if (_M_stream !=
nullptr)
972 *_M_stream >> _M_object;
973 return _Iterator{*
this};
976 constexpr default_sentinel_t
978 {
return default_sentinel; }
981 basic_istream<_CharT, _Traits>* _M_stream =
nullptr;
982 _Val _M_object = _Val();
987 using iterator_concept = input_iterator_tag;
988 using difference_type = ptrdiff_t;
989 using value_type = _Val;
991 _Iterator() =
default;
994 _Iterator(basic_istream_view& __parent) noexcept
998 _Iterator(
const _Iterator&) =
delete;
999 _Iterator(_Iterator&&) =
default;
1000 _Iterator& operator=(
const _Iterator&) =
delete;
1001 _Iterator& operator=(_Iterator&&) =
default;
1006 __glibcxx_assert(_M_parent->_M_stream !=
nullptr);
1007 *_M_parent->_M_stream >> _M_parent->_M_object;
1018 __glibcxx_assert(_M_parent->_M_stream !=
nullptr);
1019 return _M_parent->_M_object;
1023 operator==(
const _Iterator& __x, default_sentinel_t)
1024 {
return __x._M_at_end(); }
1027 basic_istream_view* _M_parent =
nullptr;
1031 {
return _M_parent ==
nullptr || !*_M_parent->_M_stream; }
1037 template<
typename _Val,
typename _CharT,
typename _Traits>
1038 basic_istream_view<_Val, _CharT, _Traits>
1039 istream_view(basic_istream<_CharT, _Traits>& __s)
1040 {
return basic_istream_view<_Val, _CharT, _Traits>{__s}; }
1050 template<
bool _Present,
typename _Tp>
1051 using __maybe_present_t = conditional_t<_Present, _Tp, _Empty>;
1054 template<
bool _Const,
typename _Tp>
1055 using __maybe_const_t = conditional_t<_Const, const _Tp, _Tp>;
1063 template<
typename _Tp>
1064 inline constexpr
auto
1065 __maybe_refwrap(_Tp& __arg)
1066 {
return reference_wrapper<_Tp>{__arg}; }
1068 template<
typename _Tp>
1069 inline constexpr
auto
1070 __maybe_refwrap(
const _Tp& __arg)
1071 {
return reference_wrapper<const _Tp>{__arg}; }
1073 template<
typename _Tp>
1074 inline constexpr decltype(
auto)
1075 __maybe_refwrap(_Tp&& __arg)
1076 {
return std::forward<_Tp>(__arg); }
1078 template<
typename _Callable>
1079 struct _RangeAdaptorClosure;
1081 template<
typename _Callable>
1082 struct _RangeAdaptor
1085 [[no_unique_address]]
1086 __detail::__maybe_present_t<!is_default_constructible_v<_Callable>,
1087 _Callable> _M_callable;
1091 _RangeAdaptor(
const _Callable& = {})
1092 requires is_default_constructible_v<_Callable>
1096 _RangeAdaptor(_Callable __callable)
1097 requires (!is_default_constructible_v<_Callable>)
1098 : _M_callable(std::
move(__callable))
1101 template<
typename... _Args>
1102 requires (
sizeof...(_Args) >= 1)
1104 operator()(_Args&&... __args)
const
1117 if constexpr (is_invocable_v<_Callable, _Args...>)
1119 static_assert(
sizeof...(_Args) != 1,
1120 "a _RangeAdaptor that accepts only one argument "
1121 "should be defined as a _RangeAdaptorClosure");
1124 return _Callable{}(std::forward<_Args>(__args)...);
1137 = [...__args(__maybe_refwrap(std::forward<_Args>(__args)))]
1138 <
typename _Range> (_Range&& __r) {
1142 return _Callable{}(std::forward<_Range>(__r),
1143 (
static_cast<unwrap_reference_t
1144 <remove_const_t<decltype(__args)>
>>
1147 using _ClosureType = decltype(__closure);
1148 return _RangeAdaptorClosure<_ClosureType>(
std::move(__closure));
1153 template<
typename _Callable>
1154 _RangeAdaptor(_Callable) -> _RangeAdaptor<_Callable>;
1156 template<
typename _Callable>
1157 struct _RangeAdaptorClosure :
public _RangeAdaptor<_Callable>
1159 using _RangeAdaptor<_Callable>::_RangeAdaptor;
1161 template<viewable_range _Range>
1162 requires requires { declval<_Callable>()(declval<_Range>()); }
1164 operator()(_Range&& __r)
const
1166 if constexpr (is_default_constructible_v<_Callable>)
1167 return _Callable{}(std::forward<_Range>(__r));
1169 return this->_M_callable(std::forward<_Range>(__r));
1172 template<viewable_range _Range>
1173 requires requires { declval<_Callable>()(declval<_Range>()); }
1174 friend constexpr
auto
1175 operator|(_Range&& __r,
const _RangeAdaptorClosure& __o)
1176 {
return __o(std::forward<_Range>(__r)); }
1178 template<
typename _Tp>
1179 friend constexpr
auto
1180 operator|(
const _RangeAdaptorClosure<_Tp>& __x,
1181 const _RangeAdaptorClosure& __y)
1183 if constexpr (is_default_constructible_v<_Tp>
1184 && is_default_constructible_v<_Callable>)
1186 auto __closure = [] <
typename _Up> (_Up&& __e) {
1187 return std::forward<_Up>(__e) | decltype(__x){} | decltype(__y){};
1189 return _RangeAdaptorClosure<decltype(__closure)>(__closure);
1191 else if constexpr (is_default_constructible_v<_Tp>
1192 && !is_default_constructible_v<_Callable>)
1194 auto __closure = [__y] <
typename _Up> (_Up&& __e) {
1195 return std::forward<_Up>(__e) | decltype(__x){} | __y;
1197 return _RangeAdaptorClosure<decltype(__closure)>(__closure);
1199 else if constexpr (!is_default_constructible_v<_Tp>
1200 && is_default_constructible_v<_Callable>)
1202 auto __closure = [__x] <
typename _Up> (_Up&& __e) {
1203 return std::forward<_Up>(__e) | __x | decltype(__y){};
1205 return _RangeAdaptorClosure<decltype(__closure)>(__closure);
1209 auto __closure = [__x, __y] <
typename _Up> (_Up&& __e) {
1210 return std::forward<_Up>(__e) | __x | __y;
1212 return _RangeAdaptorClosure<decltype(__closure)>(__closure);
1217 template<
typename _Callable>
1218 _RangeAdaptorClosure(_Callable) -> _RangeAdaptorClosure<_Callable>;
1222 template<range _Range> requires is_object_v<_Range>
1223 class ref_view :
public view_interface<ref_view<_Range>>
1226 _Range* _M_r =
nullptr;
1228 static void _S_fun(_Range&);
1229 static void _S_fun(_Range&&) =
delete;
1233 ref_view() noexcept = default;
1235 template<__detail::__not_same_as<ref_view> _Tp>
1236 requires convertible_to<_Tp, _Range&>
1237 && requires { _S_fun(declval<_Tp>()); }
1247 constexpr iterator_t<_Range>
1251 constexpr sentinel_t<_Range>
1256 empty() const requires requires { ranges::empty(*_M_r); }
1257 {
return ranges::empty(*_M_r); }
1260 size() const requires sized_range<_Range>
1261 {
return ranges::size(*_M_r); }
1264 data() const requires contiguous_range<_Range>
1265 {
return ranges::data(*_M_r); }
1268 template<
typename _Range>
1269 ref_view(_Range&) -> ref_view<_Range>;
1271 template<
typename _Tp>
1272 inline constexpr
bool enable_borrowed_range<ref_view<_Tp>> =
true;
1276 inline constexpr __adaptor::_RangeAdaptorClosure all
1277 = [] <viewable_range _Range> (_Range&& __r)
1279 if constexpr (view<decay_t<_Range>>)
1280 return std::
forward<_Range>(__r);
1281 else if constexpr (requires { ref_view{std::forward<_Range>(__r)}; })
1282 return ref_view{std::forward<_Range>(__r)};
1284 return subrange{std::forward<_Range>(__r)};
1287 template<viewable_range _Range>
1288 using all_t = decltype(all(std::declval<_Range>()));
1296 template<input_iterator _Iter, sentinel_for<_Iter> _Sent,
1297 typename _Proj =
identity,
1298 indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
1300 find_if(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {})
1302 while (__first != __last
1303 && !(
bool)std::__invoke(__pred, std::__invoke(__proj, *__first)))
1308 template<input_iterator _Iter, sentinel_for<_Iter> _Sent,
1309 typename _Proj =
identity,
1310 indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
1312 find_if_not(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {})
1314 while (__first != __last
1315 && (
bool)std::__invoke(__pred, std::__invoke(__proj, *__first)))
1320 template<
typename _Tp,
typename _Proj = identity,
1321 indirect_strict_weak_order<projected<const _Tp*, _Proj>>
1322 _Comp = ranges::less>
1323 constexpr
const _Tp&
1324 min(
const _Tp& __a,
const _Tp& __b, _Comp __comp = {}, _Proj __proj = {})
1327 std::__invoke(__proj, __b),
1328 std::__invoke(__proj, __a)))
1334 template<input_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
1335 input_iterator _Iter2, sentinel_for<_Iter2> _Sent2,
1336 typename _Pred = ranges::equal_to,
1337 typename _Proj1 =
identity,
typename _Proj2 =
identity>
1338 requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
1339 constexpr pair<_Iter1, _Iter2>
1340 mismatch(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
1341 _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {})
1343 while (__first1 != __last1 && __first2 != __last2
1344 && (
bool)std::__invoke(__pred,
1345 std::__invoke(__proj1, *__first1),
1346 std::__invoke(__proj2, *__first2)))
1357 template<range _Range>
1358 struct _CachedPosition
1361 _M_has_value()
const
1364 constexpr iterator_t<_Range>
1365 _M_get(
const _Range&)
const
1367 __glibcxx_assert(
false);
1372 _M_set(
const _Range&,
const iterator_t<_Range>&)
const
1376 template<forward_range _Range>
1377 struct _CachedPosition<_Range>
1380 iterator_t<_Range> _M_iter{};
1384 _M_has_value()
const
1385 {
return _M_iter != iterator_t<_Range>{}; }
1387 constexpr iterator_t<_Range>
1388 _M_get(
const _Range&)
const
1390 __glibcxx_assert(_M_has_value());
1395 _M_set(
const _Range&,
const iterator_t<_Range>& __it)
1397 __glibcxx_assert(!_M_has_value());
1402 template<random_access_range _Range>
1403 requires (
sizeof(range_difference_t<_Range>)
1404 <=
sizeof(iterator_t<_Range>))
1405 struct _CachedPosition<_Range>
1408 range_difference_t<_Range> _M_offset = -1;
1412 _M_has_value()
const
1413 {
return _M_offset >= 0; }
1415 constexpr iterator_t<_Range>
1416 _M_get(_Range& __r)
const
1418 __glibcxx_assert(_M_has_value());
1423 _M_set(_Range& __r,
const iterator_t<_Range>& __it)
1425 __glibcxx_assert(!_M_has_value());
1432 template<input_range _Vp,
1433 indirect_unary_predicate<iterator_t<_Vp>> _Pred>
1434 requires view<_Vp> && is_object_v<_Pred>
1435 class filter_view :
public view_interface<filter_view<_Vp, _Pred>>
1443 static constexpr
auto
1446 if constexpr (bidirectional_range<_Vp>)
1447 return bidirectional_iterator_tag{};
1448 else if constexpr (forward_range<_Vp>)
1449 return forward_iterator_tag{};
1451 return input_iterator_tag{};
1454 static constexpr
auto
1457 using _Cat =
typename iterator_traits<_Vp_iter>::iterator_category;
1458 if constexpr (derived_from<_Cat, bidirectional_iterator_tag>)
1459 return bidirectional_iterator_tag{};
1460 else if constexpr (derived_from<_Cat, forward_iterator_tag>)
1461 return forward_iterator_tag{};
1468 using _Vp_iter = iterator_t<_Vp>;
1470 _Vp_iter _M_current = _Vp_iter();
1471 filter_view* _M_parent =
nullptr;
1474 using iterator_concept = decltype(_S_iter_concept());
1475 using iterator_category = decltype(_S_iter_cat());
1476 using value_type = range_value_t<_Vp>;
1477 using difference_type = range_difference_t<_Vp>;
1479 _Iterator() =
default;
1482 _Iterator(filter_view& __parent, _Vp_iter __current)
1483 : _M_current(std::
move(__current)),
1489 requires copyable<_Vp_iter>
1490 {
return _M_current; }
1496 constexpr range_reference_t<_Vp>
1498 {
return *_M_current; }
1502 requires __detail::__has_arrow<_Vp_iter>
1503 && copyable<_Vp_iter>
1504 {
return _M_current; }
1506 constexpr _Iterator&
1509 _M_current = __detail::find_if(
std::move(++_M_current),
1511 std::ref(*_M_parent->_M_pred));
1520 operator++(
int) requires forward_range<_Vp>
1527 constexpr _Iterator&
1528 operator--() requires bidirectional_range<_Vp>
1532 while (!std::__invoke(*_M_parent->_M_pred, *_M_current));
1537 operator--(
int) requires bidirectional_range<_Vp>
1544 friend constexpr
bool
1545 operator==(
const _Iterator& __x,
const _Iterator& __y)
1546 requires equality_comparable<_Vp_iter>
1547 {
return __x._M_current == __y._M_current; }
1549 friend constexpr range_rvalue_reference_t<_Vp>
1550 iter_move(
const _Iterator& __i)
1551 noexcept(noexcept(ranges::iter_move(__i._M_current)))
1552 {
return ranges::iter_move(__i._M_current); }
1554 friend constexpr
void
1555 iter_swap(
const _Iterator& __x,
const _Iterator& __y)
1556 noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current)))
1557 requires indirectly_swappable<_Vp_iter>
1558 { ranges::iter_swap(__x._M_current, __y._M_current); }
1564 sentinel_t<_Vp> _M_end = sentinel_t<_Vp>();
1567 __equal(
const _Iterator& __i)
const
1568 {
return __i._M_current == _M_end; }
1571 _Sentinel() =
default;
1574 _Sentinel(filter_view& __parent)
1575 : _M_end(ranges::end(__parent._M_base))
1578 constexpr sentinel_t<_Vp>
1582 friend constexpr
bool
1583 operator==(
const _Iterator& __x,
const _Sentinel& __y)
1584 {
return __y.__equal(__x); }
1587 _Vp _M_base = _Vp();
1588 __detail::__box<_Pred> _M_pred;
1589 [[no_unique_address]] __detail::_CachedPosition<_Vp> _M_cached_begin;
1592 filter_view() =
default;
1595 filter_view(_Vp
__base, _Pred __pred)
1596 : _M_base(std::
move(__base)), _M_pred(std::
move(__pred))
1600 base() const& requires copy_constructible<_Vp>
1607 constexpr
const _Pred&
1609 {
return *_M_pred; }
1614 if (_M_cached_begin._M_has_value())
1615 return {*
this, _M_cached_begin._M_get(_M_base)};
1617 __glibcxx_assert(_M_pred.has_value());
1620 std::ref(*_M_pred));
1621 _M_cached_begin._M_set(_M_base, __it);
1628 if constexpr (common_range<_Vp>)
1631 return _Sentinel{*
this};
1635 template<
typename _Range,
typename _Pred>
1636 filter_view(_Range&&, _Pred) -> filter_view<views::all_t<_Range>, _Pred>;
1640 inline constexpr __adaptor::_RangeAdaptor filter
1641 = [] <viewable_range _Range,
typename _Pred> (_Range&& __r, _Pred&& __p)
1643 return filter_view{std::forward<_Range>(__r), std::forward<_Pred>(__p)};
1647 template<input_range _Vp, copy_constructible _Fp>
1648 requires view<_Vp> && is_object_v<_Fp>
1649 && regular_invocable<_Fp&, range_reference_t<_Vp>>
1650 && std::__detail::__can_reference<invoke_result_t<_Fp&,
1651 range_reference_t<_Vp>>>
1652 class transform_view :
public view_interface<transform_view<_Vp, _Fp>>
1655 template<
bool _Const>
1658 template<
bool _Const>
1662 using _Parent = __detail::__maybe_const_t<_Const, transform_view>;
1663 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
1665 static constexpr
auto
1668 if constexpr (random_access_range<_Vp>)
1669 return random_access_iterator_tag{};
1670 else if constexpr (bidirectional_range<_Vp>)
1671 return bidirectional_iterator_tag{};
1672 else if constexpr (forward_range<_Vp>)
1673 return forward_iterator_tag{};
1675 return input_iterator_tag{};
1678 static constexpr
auto
1681 using _Res = invoke_result_t<_Fp&, range_reference_t<_Base>>;
1682 if constexpr (is_lvalue_reference_v<_Res>)
1685 =
typename iterator_traits<_Base_iter>::iterator_category;
1686 if constexpr (derived_from<_Cat, contiguous_iterator_tag>)
1687 return random_access_iterator_tag{};
1692 return input_iterator_tag{};
1695 using _Base_iter = iterator_t<_Base>;
1697 _Base_iter _M_current = _Base_iter();
1698 _Parent* _M_parent =
nullptr;
1701 using iterator_concept = decltype(_S_iter_concept());
1702 using iterator_category = decltype(_S_iter_cat());
1704 = remove_cvref_t<invoke_result_t<_Fp&, range_reference_t<_Base>>>;
1705 using difference_type = range_difference_t<_Base>;
1707 _Iterator() =
default;
1710 _Iterator(_Parent& __parent, _Base_iter __current)
1711 : _M_current(std::
move(__current)),
1716 _Iterator(_Iterator<!_Const> __i)
1718 && convertible_to<iterator_t<_Vp>, _Base_iter>
1719 : _M_current(
std::move(__i._M_current)), _M_parent(__i._M_parent)
1722 constexpr _Base_iter
1724 requires copyable<_Base_iter>
1725 {
return _M_current; }
1727 constexpr _Base_iter
1731 constexpr decltype(
auto)
1733 noexcept(noexcept(std::__invoke(*_M_parent->_M_fun, *_M_current)))
1734 {
return std::__invoke(*_M_parent->_M_fun, *_M_current); }
1736 constexpr _Iterator&
1748 operator++(
int) requires forward_range<_Base>
1755 constexpr _Iterator&
1756 operator--() requires bidirectional_range<_Base>
1763 operator--(
int) requires bidirectional_range<_Base>
1770 constexpr _Iterator&
1771 operator+=(difference_type __n) requires random_access_range<_Base>
1777 constexpr _Iterator&
1778 operator-=(difference_type __n) requires random_access_range<_Base>
1784 constexpr decltype(
auto)
1785 operator[](difference_type __n) const
1786 requires random_access_range<_Base>
1787 {
return std::__invoke(*_M_parent->_M_fun, _M_current[__n]); }
1789 friend constexpr
bool
1790 operator==(
const _Iterator& __x,
const _Iterator& __y)
1791 requires equality_comparable<_Base_iter>
1792 {
return __x._M_current == __y._M_current; }
1794 friend constexpr
bool
1795 operator<(
const _Iterator& __x,
const _Iterator& __y)
1796 requires random_access_range<_Base>
1797 {
return __x._M_current < __y._M_current; }
1799 friend constexpr
bool
1800 operator>(
const _Iterator& __x,
const _Iterator& __y)
1801 requires random_access_range<_Base>
1802 {
return __y < __x; }
1804 friend constexpr
bool
1805 operator<=(
const _Iterator& __x,
const _Iterator& __y)
1806 requires random_access_range<_Base>
1807 {
return !(__y < __x); }
1809 friend constexpr
bool
1810 operator>=(
const _Iterator& __x,
const _Iterator& __y)
1811 requires random_access_range<_Base>
1812 {
return !(__x < __y); }
1814 #ifdef __cpp_lib_three_way_comparison
1815 friend constexpr
auto
1816 operator<=>(
const _Iterator& __x,
const _Iterator& __y)
1817 requires random_access_range<_Base>
1818 && three_way_comparable<_Base_iter>
1819 {
return __x._M_current <=> __y._M_current; }
1822 friend constexpr _Iterator
1823 operator+(_Iterator __i, difference_type __n)
1824 requires random_access_range<_Base>
1825 {
return {*__i._M_parent, __i._M_current + __n}; }
1827 friend constexpr _Iterator
1828 operator+(difference_type __n, _Iterator __i)
1829 requires random_access_range<_Base>
1830 {
return {*__i._M_parent, __i._M_current + __n}; }
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 difference_type
1838 operator-(
const _Iterator& __x,
const _Iterator& __y)
1839 requires random_access_range<_Base>
1840 {
return __x._M_current - __y._M_current; }
1842 friend constexpr decltype(
auto)
1843 iter_move(const _Iterator& __i) noexcept(noexcept(*__i))
1845 if constexpr (is_lvalue_reference_v<decltype(*__i)>)
1846 return std::
move(*__i);
1851 friend constexpr
void
1852 iter_swap(const _Iterator& __x, const _Iterator& __y)
1853 noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current)))
1854 requires indirectly_swappable<_Base_iter>
1855 {
return ranges::iter_swap(__x._M_current, __y._M_current); }
1857 friend _Iterator<!_Const>;
1858 template<
bool>
friend struct _Sentinel;
1861 template<
bool _Const>
1865 using _Parent = __detail::__maybe_const_t<_Const, transform_view>;
1866 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
1868 template<
bool _Const2>
1870 __distance_from(
const _Iterator<_Const2>& __i)
const
1871 {
return _M_end - __i._M_current; }
1873 template<
bool _Const2>
1875 __equal(
const _Iterator<_Const2>& __i)
const
1876 {
return __i._M_current == _M_end; }
1878 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
1881 _Sentinel() =
default;
1884 _Sentinel(sentinel_t<_Base> __end)
1889 _Sentinel(_Sentinel<!_Const> __i)
1891 && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
1895 constexpr sentinel_t<_Base>
1899 template<
bool _Const2>
1900 requires sentinel_for<sentinel_t<_Base>,
1901 iterator_t<__detail::__maybe_const_t<_Const2, _Vp>>>
1902 friend constexpr
bool
1903 operator==(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
1904 {
return __y.__equal(__x); }
1906 template<
bool _Const2,
1907 typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
1908 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
1909 friend constexpr range_difference_t<_Base2>
1910 operator-(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
1911 {
return -__y.__distance_from(__x); }
1913 template<
bool _Const2,
1914 typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
1915 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
1916 friend constexpr range_difference_t<_Base2>
1917 operator-(
const _Sentinel& __y,
const _Iterator<_Const2>& __x)
1918 {
return __y.__distance_from(__x); }
1920 friend _Sentinel<!_Const>;
1923 _Vp _M_base = _Vp();
1924 __detail::__box<_Fp> _M_fun;
1927 transform_view() =
default;
1930 transform_view(_Vp
__base, _Fp __fun)
1931 : _M_base(std::
move(__base)), _M_fun(std::
move(__fun))
1935 base() const& requires copy_constructible<_Vp>
1936 {
return _M_base ; }
1942 constexpr _Iterator<false>
1946 constexpr _Iterator<true>
1948 requires range<const _Vp>
1949 && regular_invocable<const _Fp&, range_reference_t<const _Vp>>
1952 constexpr _Sentinel<false>
1954 {
return _Sentinel<false>{
ranges::end(_M_base)}; }
1956 constexpr _Iterator<false>
1957 end() requires common_range<_Vp>
1958 {
return _Iterator<false>{*
this,
ranges::end(_M_base)}; }
1960 constexpr _Sentinel<true>
1962 requires range<const _Vp>
1963 && regular_invocable<const _Fp&, range_reference_t<const _Vp>>
1966 constexpr _Iterator<true>
1968 requires common_range<const _Vp>
1969 && regular_invocable<const _Fp&, range_reference_t<const _Vp>>
1970 {
return _Iterator<true>{*
this,
ranges::end(_M_base)}; }
1973 size() requires sized_range<_Vp>
1974 {
return ranges::size(_M_base); }
1977 size() const requires sized_range<const _Vp>
1978 {
return ranges::size(_M_base); }
1981 template<
typename _Range,
typename _Fp>
1982 transform_view(_Range&&, _Fp) -> transform_view<views::all_t<_Range>, _Fp>;
1986 inline constexpr __adaptor::_RangeAdaptor transform
1987 = [] <viewable_range _Range,
typename _Fp> (_Range&& __r, _Fp&& __f)
1989 return transform_view{std::forward<_Range>(__r), std::forward<_Fp>(__f)};
1994 class take_view :
public view_interface<take_view<_Vp>>
1997 template<
bool _Const>
1998 using _CI = counted_iterator<
1999 iterator_t<__detail::__maybe_const_t<_Const, _Vp>>>;
2001 template<
bool _Const>
2005 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2006 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
2009 _Sentinel() =
default;
2012 _Sentinel(sentinel_t<_Base> __end)
2017 _Sentinel(_Sentinel<!_Const> __s)
2018 requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
2022 constexpr sentinel_t<_Base>
2026 friend constexpr
bool
2027 operator==(
const _CI<_Const>& __y,
const _Sentinel& __x)
2028 {
return __y.count() == 0 || __y.base() == __x._M_end; }
2030 template<
bool _OtherConst = !_Const,
2031 typename _Base2 = __detail::__maybe_const_t<_OtherConst, _Vp>>
2032 requires sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
2033 friend constexpr
bool
2034 operator==(
const _CI<_OtherConst>& __y,
const _Sentinel& __x)
2035 {
return __y.count() == 0 || __y.base() == __x._M_end; }
2037 friend _Sentinel<!_Const>;
2040 _Vp _M_base = _Vp();
2041 range_difference_t<_Vp> _M_count = 0;
2044 take_view() =
default;
2047 take_view(_Vp base, range_difference_t<_Vp> __count)
2048 : _M_base(std::
move(base)), _M_count(std::
move(__count))
2052 base() const& requires copy_constructible<_Vp>
2060 begin() requires (!__detail::__simple_view<_Vp>)
2062 if constexpr (sized_range<_Vp>)
2064 if constexpr (random_access_range<_Vp>)
2065 return ranges::begin(_M_base);
2077 begin() const requires range<const _Vp>
2079 if constexpr (sized_range<const _Vp>)
2081 if constexpr (random_access_range<const _Vp>)
2082 return ranges::begin(_M_base);
2094 end() requires (!__detail::__simple_view<_Vp>)
2096 if constexpr (sized_range<_Vp>)
2098 if constexpr (random_access_range<_Vp>)
2099 return ranges::begin(_M_base) + size();
2101 return default_sentinel;
2108 end() const requires range<const _Vp>
2110 if constexpr (sized_range<const _Vp>)
2112 if constexpr (random_access_range<const _Vp>)
2113 return ranges::begin(_M_base) + size();
2115 return default_sentinel;
2122 size() requires sized_range<_Vp>
2124 auto __n = ranges::size(_M_base);
2125 return __detail::min(__n,
static_cast<decltype(__n)
>(_M_count));
2129 size() const requires sized_range<const _Vp>
2131 auto __n = ranges::size(_M_base);
2132 return __detail::min(__n,
static_cast<decltype(__n)
>(_M_count));
2139 template<
typename _Range>
2140 take_view(_Range&&, range_difference_t<_Range>)
2141 -> take_view<views::all_t<_Range>>;
2145 inline constexpr __adaptor::_RangeAdaptor take
2146 = [] <viewable_range _Range,
typename _Tp> (_Range&& __r, _Tp&& __n)
2148 return take_view{std::forward<_Range>(__r), std::forward<_Tp>(__n)};
2152 template<view _Vp,
typename _Pred>
2153 requires input_range<_Vp> && is_object_v<_Pred>
2154 && indirect_unary_predicate<const _Pred, iterator_t<_Vp>>
2155 class take_while_view :
public view_interface<take_while_view<_Vp, _Pred>>
2157 template<
bool _Const>
2161 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2163 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
2164 const _Pred* _M_pred =
nullptr;
2167 _Sentinel() =
default;
2170 _Sentinel(sentinel_t<_Base> __end,
const _Pred* __pred)
2171 : _M_end(__end), _M_pred(__pred)
2175 _Sentinel(_Sentinel<!_Const> __s)
2176 requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
2177 : _M_end(__s._M_end), _M_pred(__s._M_pred)
2180 constexpr sentinel_t<_Base>
2181 base()
const {
return _M_end; }
2183 friend constexpr
bool
2184 operator==(
const iterator_t<_Base>& __x,
const _Sentinel& __y)
2185 {
return __y._M_end == __x || !std::__invoke(*__y._M_pred, *__x); }
2187 template<
bool _OtherConst = !_Const,
2188 typename _Base2 = __detail::__maybe_const_t<_OtherConst, _Vp>>
2189 requires sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
2190 friend constexpr
bool
2191 operator==(
const iterator_t<_Base2>& __x,
const _Sentinel& __y)
2192 {
return __y._M_end == __x || !std::__invoke(*__y._M_pred, *__x); }
2194 friend _Sentinel<!_Const>;
2197 _Vp _M_base = _Vp();
2198 __detail::__box<_Pred> _M_pred;
2201 take_while_view() =
default;
2204 take_while_view(_Vp base, _Pred __pred)
2205 : _M_base(std::
move(base)), _M_pred(std::
move(__pred))
2210 base() const& requires copy_constructible<_Vp>
2217 constexpr
const _Pred&
2219 {
return *_M_pred; }
2222 begin() requires (!__detail::__simple_view<_Vp>)
2226 begin() const requires range<const _Vp>
2227 && indirect_unary_predicate<const _Pred, iterator_t<const _Vp>>
2231 end() requires (!__detail::__simple_view<_Vp>)
2236 end() const requires range<const _Vp>
2237 && indirect_unary_predicate<const _Pred, iterator_t<const _Vp>>
2242 template<
typename _Range,
typename _Pred>
2243 take_while_view(_Range&&, _Pred)
2244 -> take_while_view<views::all_t<_Range>, _Pred>;
2248 inline constexpr __adaptor::_RangeAdaptor take_while
2249 = [] <viewable_range _Range,
typename _Pred> (_Range&& __r, _Pred&& __p)
2251 return take_while_view{std::forward<_Range>(__r), std::forward<_Pred>(__p)};
2256 class drop_view :
public view_interface<drop_view<_Vp>>
2259 _Vp _M_base = _Vp();
2260 range_difference_t<_Vp> _M_count = 0;
2262 static constexpr
bool _S_needs_cached_begin = !random_access_range<_Vp>;
2263 [[no_unique_address]]
2264 __detail::__maybe_present_t<_S_needs_cached_begin,
2265 __detail::_CachedPosition<_Vp>>
2269 drop_view() =
default;
2272 drop_view(_Vp
__base, range_difference_t<_Vp> __count)
2273 : _M_base(std::
move(__base)), _M_count(__count)
2274 { __glibcxx_assert(__count >= 0); }
2277 base() const& requires copy_constructible<_Vp>
2285 begin() requires (!(__detail::__simple_view<_Vp>
2286 && random_access_range<_Vp>))
2288 if constexpr (_S_needs_cached_begin)
2289 if (_M_cached_begin._M_has_value())
2290 return _M_cached_begin._M_get(_M_base);
2292 auto __it = ranges::next(ranges::begin(_M_base),
2293 _M_count, ranges::end(_M_base));
2294 if constexpr (_S_needs_cached_begin)
2295 _M_cached_begin._M_set(_M_base, __it);
2300 begin() const requires random_access_range<const _Vp>
2307 end() requires (!__detail::__simple_view<_Vp>)
2311 end() const requires range<const _Vp>
2315 size() requires sized_range<_Vp>
2317 const auto __s = ranges::size(_M_base);
2318 const auto __c =
static_cast<decltype(__s)
>(_M_count);
2319 return __s < __c ? 0 : __s - __c;
2323 size() const requires sized_range<const _Vp>
2325 const auto __s = ranges::size(_M_base);
2326 const auto __c =
static_cast<decltype(__s)
>(_M_count);
2327 return __s < __c ? 0 : __s - __c;
2331 template<
typename _Range>
2332 drop_view(_Range&&, range_difference_t<_Range>)
2333 -> drop_view<views::all_t<_Range>>;
2337 inline constexpr __adaptor::_RangeAdaptor drop
2338 = [] <viewable_range _Range,
typename _Tp> (_Range&& __r, _Tp&& __n)
2340 return drop_view{std::forward<_Range>(__r), std::forward<_Tp>(__n)};
2344 template<view _Vp,
typename _Pred>
2345 requires input_range<_Vp> && is_object_v<_Pred>
2346 && indirect_unary_predicate<const _Pred, iterator_t<_Vp>>
2347 class drop_while_view :
public view_interface<drop_while_view<_Vp, _Pred>>
2350 _Vp _M_base = _Vp();
2351 __detail::__box<_Pred> _M_pred;
2352 [[no_unique_address]] __detail::_CachedPosition<_Vp> _M_cached_begin;
2355 drop_while_view() =
default;
2358 drop_while_view(_Vp
__base, _Pred __pred)
2359 : _M_base(std::
move(__base)), _M_pred(std::
move(__pred))
2363 base() const& requires copy_constructible<_Vp>
2370 constexpr
const _Pred&
2372 {
return *_M_pred; }
2377 if (_M_cached_begin._M_has_value())
2378 return _M_cached_begin._M_get(_M_base);
2382 std::cref(*_M_pred));
2383 _M_cached_begin._M_set(_M_base, __it);
2392 template<
typename _Range,
typename _Pred>
2393 drop_while_view(_Range&&, _Pred)
2394 -> drop_while_view<views::all_t<_Range>, _Pred>;
2398 inline constexpr __adaptor::_RangeAdaptor drop_while
2399 = [] <viewable_range _Range,
typename _Pred> (_Range&& __r, _Pred&& __p)
2401 return drop_while_view{std::forward<_Range>(__r),
2402 std::forward<_Pred>(__p)};
2406 template<input_range _Vp>
2407 requires view<_Vp> && input_range<range_reference_t<_Vp>>
2408 && (is_reference_v<range_reference_t<_Vp>>
2409 || view<range_value_t<_Vp>>)
2410 class join_view :
public view_interface<join_view<_Vp>>
2413 using _InnerRange = range_reference_t<_Vp>;
2415 template<
bool _Const>
2418 template<
bool _Const>
2422 using _Parent = __detail::__maybe_const_t<_Const, join_view>;
2423 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2425 static constexpr
bool _S_ref_is_glvalue
2426 = is_reference_v<range_reference_t<_Base>>;
2431 auto __update_inner = [
this] (range_reference_t<_Base> __x) ->
auto&
2433 if constexpr (_S_ref_is_glvalue)
2436 return (_M_parent->_M_inner = views::all(std::
move(__x)));
2439 for (; _M_outer != ranges::end(_M_parent->_M_base); ++_M_outer)
2441 auto& __inner = __update_inner(*_M_outer);
2447 if constexpr (_S_ref_is_glvalue)
2448 _M_inner = _Inner_iter();
2451 static constexpr auto
2454 if constexpr (_S_ref_is_glvalue
2455 && bidirectional_range<_Base>
2456 && bidirectional_range<range_reference_t<_Base>>)
2457 return bidirectional_iterator_tag{};
2458 else if constexpr (_S_ref_is_glvalue
2459 && forward_range<_Base>
2460 && forward_range<range_reference_t<_Base>>)
2461 return forward_iterator_tag{};
2463 return input_iterator_tag{};
2466 static constexpr
auto
2470 =
typename iterator_traits<_Outer_iter>::iterator_category;
2472 =
typename iterator_traits<_Inner_iter>::iterator_category;
2473 if constexpr (_S_ref_is_glvalue
2474 && derived_from<_OuterCat, bidirectional_iterator_tag>
2475 && derived_from<_InnerCat, bidirectional_iterator_tag>)
2476 return bidirectional_iterator_tag{};
2477 else if constexpr (_S_ref_is_glvalue
2478 && derived_from<_OuterCat, forward_iterator_tag>
2479 && derived_from<_InnerCat, forward_iterator_tag>)
2480 return forward_iterator_tag{};
2481 else if constexpr (derived_from<_OuterCat, input_iterator_tag>
2482 && derived_from<_InnerCat, input_iterator_tag>)
2483 return input_iterator_tag{};
2485 return output_iterator_tag{};
2488 using _Outer_iter = iterator_t<_Base>;
2489 using _Inner_iter = iterator_t<range_reference_t<_Base>>;
2491 _Outer_iter _M_outer = _Outer_iter();
2492 _Inner_iter _M_inner = _Inner_iter();
2493 _Parent* _M_parent =
nullptr;
2496 using iterator_concept = decltype(_S_iter_concept());
2497 using iterator_category = decltype(_S_iter_cat());
2498 using value_type = range_value_t<range_reference_t<_Base>>;
2499 using difference_type
2500 = common_type_t<range_difference_t<_Base>,
2501 range_difference_t<range_reference_t<_Base>>>;
2503 _Iterator() =
default;
2506 _Iterator(_Parent& __parent, _Outer_iter __outer)
2507 : _M_outer(std::
move(__outer)),
2512 _Iterator(_Iterator<!_Const> __i)
2514 && convertible_to<iterator_t<_Vp>, _Outer_iter>
2515 && convertible_to<iterator_t<_InnerRange>, _Inner_iter>
2516 : _M_outer(
std::move(__i._M_outer)), _M_inner(__i._M_inner),
2517 _M_parent(__i._M_parent)
2520 constexpr decltype(
auto)
2522 {
return *_M_inner; }
2526 constexpr _Inner_iter
2528 requires __detail::__has_arrow<_Inner_iter>
2529 && copyable<_Inner_iter>
2530 {
return _M_inner; }
2532 constexpr _Iterator&
2535 auto&& __inner_range = [
this] () -> decltype(
auto) {
2536 if constexpr (_S_ref_is_glvalue)
2539 return _M_parent->_M_inner;
2541 if (++_M_inner == ranges::end(__inner_range))
2555 requires _S_ref_is_glvalue && forward_range<_Base>
2556 && forward_range<range_reference_t<_Base>>
2563 constexpr _Iterator&
2565 requires _S_ref_is_glvalue && bidirectional_range<_Base>
2566 && bidirectional_range<range_reference_t<_Base>>
2567 && common_range<range_reference_t<_Base>>
2579 requires _S_ref_is_glvalue && bidirectional_range<_Base>
2580 && bidirectional_range<range_reference_t<_Base>>
2581 && common_range<range_reference_t<_Base>>
2588 friend constexpr
bool
2589 operator==(
const _Iterator& __x,
const _Iterator& __y)
2590 requires _S_ref_is_glvalue
2591 && equality_comparable<_Outer_iter>
2592 && equality_comparable<_Inner_iter>
2594 return (__x._M_outer == __y._M_outer
2595 && __x._M_inner == __y._M_inner);
2598 friend constexpr decltype(
auto)
2599 iter_move(const _Iterator& __i)
2600 noexcept(noexcept(ranges::iter_move(__i._M_inner)))
2601 {
return ranges::iter_move(__i._M_inner); }
2603 friend constexpr
void
2604 iter_swap(
const _Iterator& __x,
const _Iterator& __y)
2605 noexcept(noexcept(ranges::iter_swap(__x._M_inner, __y._M_inner)))
2606 {
return ranges::iter_swap(__x._M_inner, __y._M_inner); }
2608 friend _Iterator<!_Const>;
2609 template<
bool>
friend struct _Sentinel;
2612 template<
bool _Const>
2616 using _Parent = __detail::__maybe_const_t<_Const, join_view>;
2617 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2619 template<
bool _Const2>
2621 __equal(
const _Iterator<_Const2>& __i)
const
2622 {
return __i._M_outer == _M_end; }
2624 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
2627 _Sentinel() =
default;
2630 _Sentinel(_Parent& __parent)
2631 : _M_end(ranges::end(__parent._M_base))
2635 _Sentinel(_Sentinel<!_Const> __s)
2636 requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
2640 template<
bool _Const2>
2641 requires sentinel_for<sentinel_t<_Base>,
2642 iterator_t<__detail::__maybe_const_t<_Const2, _Vp>>>
2643 friend constexpr
bool
2644 operator==(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
2645 {
return __y.__equal(__x); }
2647 friend _Sentinel<!_Const>;
2650 _Vp _M_base = _Vp();
2653 [[no_unique_address]]
2654 __detail::__maybe_present_t<!is_reference_v<_InnerRange>,
2655 views::all_t<_InnerRange>> _M_inner;
2658 join_view() =
default;
2662 : _M_base(std::
move(__base))
2666 base() const& requires copy_constructible<_Vp>
2676 constexpr
bool __use_const
2677 = (__detail::__simple_view<_Vp>
2678 && is_reference_v<range_reference_t<_Vp>>);
2679 return _Iterator<__use_const>{*
this,
ranges::begin(_M_base)};
2684 requires input_range<const _Vp>
2685 && is_reference_v<range_reference_t<const _Vp>>
2693 if constexpr (forward_range<_Vp> && is_reference_v<_InnerRange>
2694 && forward_range<_InnerRange>
2695 && common_range<_Vp> && common_range<_InnerRange>)
2696 return _Iterator<__detail::__simple_view<_Vp>>{*
this,
2699 return _Sentinel<__detail::__simple_view<_Vp>>{*
this};
2704 requires input_range<const _Vp>
2705 && is_reference_v<range_reference_t<const _Vp>>
2707 if constexpr (forward_range<const _Vp>
2708 && is_reference_v<range_reference_t<const _Vp>>
2709 && forward_range<range_reference_t<const _Vp>>
2710 && common_range<const _Vp>
2711 && common_range<range_reference_t<const _Vp>>)
2712 return _Iterator<true>{*
this,
ranges::end(_M_base)};
2714 return _Sentinel<true>{*
this};
2718 template<
typename _Range>
2719 explicit join_view(_Range&&) -> join_view<views::all_t<_Range>>;
2723 inline constexpr __adaptor::_RangeAdaptorClosure join
2724 = [] <viewable_range _Range> (_Range&& __r)
2728 return join_view<views::all_t<_Range>>{std::forward<_Range>(__r)};
2735 struct __require_constant;
2737 template<
typename _Range>
2738 concept __tiny_range = sized_range<_Range>
2740 {
typename __require_constant<remove_reference_t<_Range>::size()>; }
2741 && (remove_reference_t<_Range>::size() <= 1);
2744 template<input_range _Vp, forward_range _Pattern>
2745 requires view<_Vp> && view<_Pattern>
2746 && indirectly_comparable<iterator_t<_Vp>, iterator_t<_Pattern>,
2748 && (forward_range<_Vp> || __detail::__tiny_range<_Pattern>)
2749 class split_view :
public view_interface<split_view<_Vp, _Pattern>>
2752 template<
bool _Const>
2755 template<
bool _Const>
2759 using _Parent = __detail::__maybe_const_t<_Const, split_view>;
2760 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2764 {
return __current() ==
ranges::end(_M_parent->_M_base); }
2771 __current() noexcept
2773 if constexpr (forward_range<_Vp>)
2776 return _M_parent->_M_current;
2780 __current() const noexcept
2782 if constexpr (forward_range<_Vp>)
2785 return _M_parent->_M_current;
2788 _Parent* _M_parent =
nullptr;
2791 [[no_unique_address]]
2792 __detail::__maybe_present_t<forward_range<_Vp>,
2793 iterator_t<_Base>> _M_current;
2796 using iterator_concept =
conditional_t<forward_range<_Base>,
2797 forward_iterator_tag,
2798 input_iterator_tag>;
2799 using iterator_category = input_iterator_tag;
2800 using difference_type = range_difference_t<_Base>;
2802 struct value_type : view_interface<value_type>
2805 _OuterIter _M_i = _OuterIter();
2808 value_type() =
default;
2811 value_type(_OuterIter __i)
2812 : _M_i(std::
move(__i))
2815 constexpr _InnerIter<_Const>
2817 requires copyable<_OuterIter>
2818 {
return _InnerIter<_Const>{_M_i}; }
2820 constexpr _InnerIter<_Const>
2822 requires (!copyable<_OuterIter>)
2823 {
return _InnerIter<_Const>{
std::move(_M_i)}; }
2825 constexpr default_sentinel_t
2827 {
return default_sentinel; }
2830 _OuterIter() =
default;
2833 _OuterIter(_Parent& __parent) requires (!forward_range<_Base>)
2838 _OuterIter(_Parent& __parent, iterator_t<_Base> __current)
2839 requires forward_range<_Base>
2845 _OuterIter(_OuterIter<!_Const> __i)
2847 && convertible_to<iterator_t<_Vp>, iterator_t<_Base>>
2848 : _M_parent(__i._M_parent), _M_current(
std::move(__i._M_current))
2851 constexpr value_type
2853 {
return value_type{*
this}; }
2855 constexpr _OuterIter&
2858 const auto __end =
ranges::end(_M_parent->_M_base);
2859 if (__current() == __end)
2861 const auto [__pbegin, __pend] = subrange{_M_parent->_M_pattern};
2862 if (__pbegin == __pend)
2868 = __detail::mismatch(
std::move(__current()), __end,
2873 }
while (++__current() != __end);
2877 constexpr decltype(
auto)
2880 if constexpr (forward_range<_Base>)
2890 friend constexpr
bool
2891 operator==(
const _OuterIter& __x,
const _OuterIter& __y)
2892 requires forward_range<_Base>
2893 {
return __x._M_current == __y._M_current; }
2895 friend constexpr
bool
2896 operator==(
const _OuterIter& __x, default_sentinel_t)
2897 {
return __x.__at_end(); };
2899 friend _OuterIter<!_Const>;
2900 friend _InnerIter<_Const>;
2903 template<
bool _Const>
2907 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
2912 auto [__pcur, __pend] = subrange{_M_i._M_parent->_M_pattern};
2913 auto __end =
ranges::end(_M_i._M_parent->_M_base);
2914 if constexpr (__detail::__tiny_range<_Pattern>)
2916 const auto& __cur = _M_i_current();
2919 if (__pcur == __pend)
2920 return _M_incremented;
2921 return *__cur == *__pcur;
2925 auto __cur = _M_i_current();
2928 if (__pcur == __pend)
2929 return _M_incremented;
2932 if (*__cur != *__pcur)
2934 if (++__pcur == __pend)
2936 }
while (++__cur != __end);
2941 static constexpr
auto
2945 =
typename iterator_traits<iterator_t<_Base>>::iterator_category;
2946 if constexpr (derived_from<_Cat, forward_iterator_tag>)
2947 return forward_iterator_tag{};
2953 _M_i_current() noexcept
2954 {
return _M_i.__current(); }
2957 _M_i_current() const noexcept
2958 {
return _M_i.__current(); }
2960 _OuterIter<_Const> _M_i = _OuterIter<_Const>();
2961 bool _M_incremented =
false;
2964 using iterator_concept
2965 =
typename _OuterIter<_Const>::iterator_concept;
2966 using iterator_category = decltype(_S_iter_cat());
2967 using value_type = range_value_t<_Base>;
2968 using difference_type = range_difference_t<_Base>;
2970 _InnerIter() =
default;
2973 _InnerIter(_OuterIter<_Const> __i)
2974 : _M_i(std::
move(__i))
2977 constexpr decltype(
auto)
2979 {
return *_M_i_current(); }
2981 constexpr _InnerIter&
2984 _M_incremented =
true;
2985 if constexpr (!forward_range<_Base>)
2986 if constexpr (_Pattern::size() == 0)
2992 constexpr decltype(auto)
2995 if constexpr (forward_range<_Vp>)
3005 friend constexpr
bool
3006 operator==(
const _InnerIter& __x,
const _InnerIter& __y)
3007 requires forward_range<_Base>
3008 {
return __x._M_i == __y._M_i; }
3010 friend constexpr
bool
3011 operator==(
const _InnerIter& __x, default_sentinel_t)
3012 {
return __x.__at_end(); }
3014 friend constexpr decltype(
auto)
3015 iter_move(const _InnerIter& __i)
3016 noexcept(noexcept(ranges::iter_move(__i._M_i_current())))
3017 {
return ranges::iter_move(__i._M_i_current()); }
3019 friend constexpr
void
3020 iter_swap(
const _InnerIter& __x,
const _InnerIter& __y)
3021 noexcept(noexcept(ranges::iter_swap(__x._M_i_current(),
3022 __y._M_i_current())))
3023 requires indirectly_swappable<iterator_t<_Base>>
3024 { ranges::iter_swap(__x._M_i_current(), __y._M_i_current()); }
3027 _Vp _M_base = _Vp();
3028 _Pattern _M_pattern = _Pattern();
3031 [[no_unique_address]]
3032 __detail::__maybe_present_t<!forward_range<_Vp>, iterator_t<_Vp>>
3037 split_view() =
default;
3040 split_view(_Vp
__base, _Pattern __pattern)
3041 : _M_base(std::
move(__base)), _M_pattern(std::
move(__pattern))
3044 template<input_range _Range>
3045 requires constructible_from<_Vp, views::all_t<_Range>>
3046 && constructible_from<_Pattern, single_view<range_value_t<_Range>>>
3048 split_view(_Range&& __r, range_value_t<_Range> __e)
3049 : _M_base(views::all(std::
forward<_Range>(__r))),
3050 _M_pattern(std::
move(__e))
3054 base() const& requires copy_constructible<_Vp>
3064 if constexpr (forward_range<_Vp>)
3065 return _OuterIter<__detail::__simple_view<_Vp>>{
3070 return _OuterIter<false>{*
this};
3075 begin() const requires forward_range<_Vp> && forward_range<const _Vp>
3081 end() requires forward_range<_Vp> && common_range<_Vp>
3083 return _OuterIter<__detail::__simple_view<_Vp>>{
3090 if constexpr (forward_range<_Vp>
3091 && forward_range<const _Vp>
3092 && common_range<const _Vp>)
3093 return _OuterIter<true>{*
this,
ranges::end(_M_base)};
3095 return default_sentinel;
3099 template<
typename _Range,
typename _Pred>
3100 split_view(_Range&&, _Pred&&)
3101 -> split_view<views::all_t<_Range>, views::all_t<_Pred>>;
3103 template<input_range _Range>
3104 split_view(_Range&&, range_value_t<_Range>)
3105 -> split_view<views::all_t<_Range>, single_view<range_value_t<_Range>>>;
3109 inline constexpr __adaptor::_RangeAdaptor split
3110 = [] <viewable_range _Range,
typename _Fp> (_Range&& __r, _Fp&& __f)
3112 return split_view{std::forward<_Range>(__r), std::forward<_Fp>(__f)};
3120 template<input_or_output_iterator _Iter>
3122 operator()(_Iter __i, iter_difference_t<_Iter> __n)
const
3124 if constexpr (random_access_iterator<_Iter>)
3125 return subrange{__i, __i + __n};
3127 return subrange{counted_iterator{
std::move(__i), __n},
3132 inline constexpr _Counted counted{};
3136 requires (!common_range<_Vp>) && copyable<iterator_t<_Vp>>
3137 class common_view :
public view_interface<common_view<_Vp>>
3140 _Vp _M_base = _Vp();
3143 common_view() =
default;
3146 common_view(_Vp __r)
3147 : _M_base(std::
move(__r))
3161 base() const& requires copy_constructible<_Vp>
3171 if constexpr (random_access_range<_Vp> && sized_range<_Vp>)
3172 return ranges::begin(_M_base);
3174 return common_iterator<iterator_t<_Vp>, sentinel_t<_Vp>>
3175 (ranges::begin(_M_base));
3179 begin() const requires range<const _Vp>
3181 if constexpr (random_access_range<const _Vp> && sized_range<const _Vp>)
3182 return ranges::begin(_M_base);
3184 return common_iterator<iterator_t<const _Vp>, sentinel_t<const _Vp>>
3185 (ranges::begin(_M_base));
3191 if constexpr (random_access_range<_Vp> && sized_range<_Vp>)
3192 return ranges::begin(_M_base) + ranges::size(_M_base);
3194 return common_iterator<iterator_t<_Vp>, sentinel_t<_Vp>>
3195 (ranges::end(_M_base));
3199 end() const requires range<const _Vp>
3201 if constexpr (random_access_range<const _Vp> && sized_range<const _Vp>)
3202 return ranges::begin(_M_base) + ranges::size(_M_base);
3204 return common_iterator<iterator_t<const _Vp>, sentinel_t<const _Vp>>
3205 (ranges::end(_M_base));
3209 size() requires sized_range<_Vp>
3210 {
return ranges::size(_M_base); }
3213 size() const requires sized_range<const _Vp>
3214 {
return ranges::size(_M_base); }
3217 template<
typename _Range>
3218 common_view(_Range&&) -> common_view<views::all_t<_Range>>;
3222 inline constexpr __adaptor::_RangeAdaptorClosure common
3223 = [] <viewable_range _Range> (_Range&& __r)
3225 if constexpr (common_range<_Range>
3226 && requires { views::all(std::forward<_Range>(__r)); })
3227 return views::all(std::forward<_Range>(__r));
3229 return common_view{std::forward<_Range>(__r)};
3235 requires bidirectional_range<_Vp>
3236 class reverse_view :
public view_interface<reverse_view<_Vp>>
3239 _Vp _M_base = _Vp();
3241 static constexpr
bool _S_needs_cached_begin
3242 = !common_range<_Vp> && !random_access_range<_Vp>;
3243 [[no_unique_address]]
3244 __detail::__maybe_present_t<_S_needs_cached_begin,
3245 __detail::_CachedPosition<_Vp>>
3249 reverse_view() =
default;
3252 reverse_view(_Vp __r)
3253 : _M_base(std::
move(__r))
3257 base() const& requires copy_constructible<_Vp>
3264 constexpr reverse_iterator<iterator_t<_Vp>>
3267 if constexpr (_S_needs_cached_begin)
3268 if (_M_cached_begin._M_has_value())
3271 auto __it = ranges::next(ranges::begin(_M_base), ranges::end(_M_base));
3272 if constexpr (_S_needs_cached_begin)
3273 _M_cached_begin._M_set(_M_base, __it);
3278 begin() requires common_range<_Vp>
3282 begin() const requires common_range<const _Vp>
3285 constexpr reverse_iterator<iterator_t<_Vp>>
3290 end() const requires common_range<const _Vp>
3294 size() requires sized_range<_Vp>
3295 {
return ranges::size(_M_base); }
3298 size() const requires sized_range<const _Vp>
3299 {
return ranges::size(_M_base); }
3302 template<
typename _Range>
3303 reverse_view(_Range&&) -> reverse_view<views::all_t<_Range>>;
3310 inline constexpr
bool __is_reversible_subrange =
false;
3312 template<
typename _Iter, subrange_kind _Kind>
3313 inline constexpr
bool
3314 __is_reversible_subrange<subrange<reverse_iterator<_Iter>,
3315 reverse_iterator<_Iter>,
3319 inline constexpr
bool __is_reverse_view =
false;
3321 template<
typename _Vp>
3322 inline constexpr
bool __is_reverse_view<reverse_view<_Vp>> =
true;
3325 inline constexpr __adaptor::_RangeAdaptorClosure reverse
3326 = [] <viewable_range _Range> (_Range&& __r)
3328 using _Tp = remove_cvref_t<_Range>;
3329 if constexpr (__detail::__is_reverse_view<_Tp>)
3330 return std::
forward<_Range>(__r).base();
3331 else if constexpr (__detail::__is_reversible_subrange<_Tp>)
3334 if constexpr (sized_range<_Tp>)
3335 return subrange<_Iter, _Iter, subrange_kind::sized>
3336 (__r.end().base(), __r.begin().base(), __r.size());
3338 return subrange<_Iter, _Iter, subrange_kind::unsized>
3339 (__r.end().base(), __r.begin().base());
3342 return reverse_view{std::forward<_Range>(__r)};
3348 template<
typename _Tp,
size_t _Nm>
3349 concept __has_tuple_element = requires(_Tp __t)
3351 typename tuple_size<_Tp>::type;
3352 requires _Nm < tuple_size_v<_Tp>;
3353 typename tuple_element_t<_Nm, _Tp>;
3354 { std::get<_Nm>(__t) }
3355 -> convertible_to<
const tuple_element_t<_Nm, _Tp>&>;
3359 template<input_range _Vp,
size_t _Nm>
3361 && __detail::__has_tuple_element<range_value_t<_Vp>, _Nm>
3362 && __detail::__has_tuple_element<remove_reference_t<range_reference_t<_Vp>>,
3364 class elements_view :
public view_interface<elements_view<_Vp, _Nm>>
3367 elements_view() =
default;
3370 elements_view(_Vp base)
3371 : _M_base(std::
move(base))
3375 base() const& requires copy_constructible<_Vp>
3383 begin() requires (!__detail::__simple_view<_Vp>)
3387 begin() const requires range<const _Vp>
3391 end() requires (!__detail::__simple_view<_Vp> && !common_range<_Vp>)
3392 {
return _Sentinel<false>{
ranges::end(_M_base)}; }
3395 end() requires (!__detail::__simple_view<_Vp> && common_range<_Vp>)
3396 {
return _Iterator<false>{
ranges::end(_M_base)}; }
3399 end() const requires range<const _Vp>
3403 end() const requires common_range<const _Vp>
3407 size() requires sized_range<_Vp>
3408 {
return ranges::size(_M_base); }
3411 size() const requires sized_range<const _Vp>
3412 {
return ranges::size(_M_base); }
3415 template<
bool _Const>
3418 template<
bool _Const>
3421 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
3423 iterator_t<_Base> _M_current = iterator_t<_Base>();
3425 friend _Iterator<!_Const>;
3428 using iterator_category
3429 =
typename iterator_traits<iterator_t<_Base>>::iterator_category;
3431 = remove_cvref_t<tuple_element_t<_Nm, range_value_t<_Base>>>;
3432 using difference_type = range_difference_t<_Base>;
3434 _Iterator() =
default;
3437 _Iterator(iterator_t<_Base> current)
3438 : _M_current(std::
move(current))
3442 _Iterator(_Iterator<!_Const> i)
3443 requires _Const && convertible_to<iterator_t<_Vp>, iterator_t<_Base>>
3447 constexpr iterator_t<_Base>
3449 requires copyable<iterator_t<_Base>>
3450 {
return _M_current; }
3452 constexpr iterator_t<_Base>
3456 constexpr decltype(
auto)
3458 {
return std::get<_Nm>(*_M_current); }
3460 constexpr _Iterator&
3468 operator++(
int) requires (!forward_range<_Base>)
3472 operator++(
int) requires forward_range<_Base>
3479 constexpr _Iterator&
3480 operator--() requires bidirectional_range<_Base>
3487 operator--(
int) requires bidirectional_range<_Base>
3494 constexpr _Iterator&
3495 operator+=(difference_type __n)
3496 requires random_access_range<_Base>
3502 constexpr _Iterator&
3503 operator-=(difference_type __n)
3504 requires random_access_range<_Base>
3510 constexpr decltype(
auto)
3511 operator[](difference_type __n) const
3512 requires random_access_range<_Base>
3513 {
return std::get<_Nm>(*(_M_current + __n)); }
3515 friend constexpr
bool
3516 operator==(
const _Iterator& __x,
const _Iterator& __y)
3517 requires equality_comparable<iterator_t<_Base>>
3518 {
return __x._M_current == __y._M_current; }
3520 friend constexpr
bool
3521 operator<(
const _Iterator& __x,
const _Iterator& __y)
3522 requires random_access_range<_Base>
3523 {
return __x._M_current < __y._M_current; }
3525 friend constexpr
bool
3526 operator>(
const _Iterator& __x,
const _Iterator& __y)
3527 requires random_access_range<_Base>
3528 {
return __y._M_current < __x._M_current; }
3530 friend constexpr
bool
3531 operator<=(
const _Iterator& __x,
const _Iterator& __y)
3532 requires random_access_range<_Base>
3533 {
return !(__y._M_current > __x._M_current); }
3535 friend constexpr
bool
3536 operator>=(
const _Iterator& __x,
const _Iterator& __y)
3537 requires random_access_range<_Base>
3538 {
return !(__x._M_current > __y._M_current); }
3540 #ifdef __cpp_lib_three_way_comparison
3541 friend constexpr
auto
3542 operator<=>(
const _Iterator& __x,
const _Iterator& __y)
3543 requires random_access_range<_Base>
3544 && three_way_comparable<iterator_t<_Base>>
3545 {
return __x._M_current <=> __y._M_current; }
3548 friend constexpr _Iterator
3549 operator+(
const _Iterator& __x, difference_type __y)
3550 requires random_access_range<_Base>
3551 {
return _Iterator{__x} += __y; }
3553 friend constexpr _Iterator
3554 operator+(difference_type __x,
const _Iterator& __y)
3555 requires random_access_range<_Base>
3556 {
return __y + __x; }
3558 friend constexpr _Iterator
3559 operator-(
const _Iterator& __x, difference_type __y)
3560 requires random_access_range<_Base>
3561 {
return _Iterator{__x} -= __y; }
3563 friend constexpr difference_type
3564 operator-(
const _Iterator& __x,
const _Iterator& __y)
3565 requires random_access_range<_Base>
3566 {
return __x._M_current - __y._M_current; }
3568 friend _Sentinel<_Const>;
3571 template<
bool _Const>
3576 _M_equal(
const _Iterator<_Const>& __x)
const
3577 {
return __x._M_current == _M_end; }
3579 using _Base = __detail::__maybe_const_t<_Const, _Vp>;
3580 sentinel_t<_Base> _M_end = sentinel_t<_Base>();
3583 _Sentinel() =
default;
3586 _Sentinel(sentinel_t<_Base> __end)
3587 : _M_end(std::
move(__end))
3591 _Sentinel(_Sentinel<!_Const> __other)
3593 && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>>
3597 constexpr sentinel_t<_Base>
3601 template<
bool _Const2>
3602 requires sentinel_for<sentinel_t<_Base>,
3603 iterator_t<__detail::__maybe_const_t<_Const2, _Vp>>>
3604 friend constexpr
bool
3605 operator==(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
3606 {
return __y._M_equal(__x); }
3608 template<
bool _Const2,
3609 typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
3610 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
3611 friend constexpr range_difference_t<_Base2>
3612 operator-(
const _Iterator<_Const2>& __x,
const _Sentinel& __y)
3613 {
return __x._M_current - __y._M_end; }
3615 template<
bool _Const2,
3616 typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
3617 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
3618 friend constexpr range_difference_t<_Base>
3619 operator-(
const _Sentinel& __x,
const _Iterator<_Const2>& __y)
3620 {
return __x._M_end - __y._M_current; }
3622 friend _Sentinel<!_Const>;
3625 _Vp _M_base = _Vp();
3628 template<
typename _Range>
3629 using keys_view = elements_view<views::all_t<_Range>, 0>;
3631 template<
typename _Range>
3632 using values_view = elements_view<views::all_t<_Range>, 1>;
3636 template<
size_t _Nm>
3637 inline constexpr __adaptor::_RangeAdaptorClosure elements
3638 = [] <viewable_range _Range> (_Range&& __r)
3640 using _El = elements_view<views::all_t<_Range>, _Nm>;
3641 return _El{std::forward<_Range>(__r)};
3644 inline constexpr __adaptor::_RangeAdaptorClosure keys = elements<0>;
3645 inline constexpr __adaptor::_RangeAdaptorClosure values = elements<1>;
3650 namespace views = ranges::views;
3652 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3653 struct tuple_size<ranges::subrange<_Iter, _Sent, _Kind>>
3654 : integral_constant<size_t, 2>
3657 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3658 struct tuple_element<0, ranges::subrange<_Iter, _Sent, _Kind>>
3659 {
using type = _Iter; };
3661 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3662 struct tuple_element<1, ranges::subrange<_Iter, _Sent, _Kind>>
3663 {
using type = _Sent; };
3665 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3666 struct tuple_element<0, const ranges::subrange<_Iter, _Sent, _Kind>>
3667 {
using type = _Iter; };
3669 template<
typename _Iter,
typename _Sent, ranges::subrange_kind _Kind>
3670 struct tuple_element<1, const ranges::subrange<_Iter, _Sent, _Kind>>
3671 {
using type = _Sent; };
3673 _GLIBCXX_END_NAMESPACE_VERSION
3675 #endif // library concepts
constexpr complex< _Tp > operator-(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x minus y.
_Tp * begin(valarray< _Tp > &__va)
Return an iterator pointing to the first element of the valarray.
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
constexpr reverse_iterator< _Iterator > make_reverse_iterator(_Iterator __i)
Generator function for reverse_iterator.
typename conditional< _Cond, _Iftrue, _Iffalse >::type conditional_t
Alias template for conditional.
constexpr in_place_t in_place
Tag for in-place construction.
constexpr iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
constexpr _Iterator __base(_Iterator __it)
constexpr void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
_Tp * end(valarray< _Tp > &__va)
Return an iterator pointing to one past the last element of the valarray.
constexpr complex< _Tp > operator+(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x plus y.
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
constexpr complex< _Tp > operator*(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x times y.
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
bitset< _Nb > operator|(const bitset< _Nb > &__x, const bitset< _Nb > &__y) noexcept
Global bitwise operations on bitsets.
constexpr void iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value)
Create a range of sequentially increasing values.