operator==(std::ranges::take_view::sentinel<Const>)

 

C++

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Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Ranges library

Range access
begin cbegin end cend	rbegin crbegin rend crend	size ssize data cdata	empty
Range conversions
to (C++23)
Range primitives
range_size_trange_difference_t range_value_t	range_reference_trange_const_reference_trange_rvalue_reference_t   (C++23)	iterator_tconst_iterator_tsentinel_t (C++23)
Dangling iterator handling
dangling	borrowed_iterator_t	borrowed_subrange_t
Range concepts
range borrowed_range    sized_range constant_range (C++23)	common_range view viewable_range	input_range output_range forward_range	bidirectional_range random_access_range contiguous_range
Views
view_interface	subrange
Factories
empty_viewviews::empty iota_viewviews::iota	single_viewviews::single basic_istream_viewviews::istream	repeat_viewviews::repeat (C++23)(C++23)
Adaptors
ref_view views::all_tviews::all common_viewviews::common owning_view views::counted reverse_viewviews::reverse zip_viewviews::zip (C++23)(C++23) as_const_viewviews::as_const (C++23)(C++23) as_rvalue_viewviews::as_rvalue (C++23)(C++23)	take_viewviews::take take_while_viewviews::take_while drop_viewviews::drop drop_while_viewviews::drop_while zip_transform_viewviews::zip_transform (C++23)(C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23)   cartesian_product_viewviews::cartesian_product (C++23)(C++23)	elements_viewviews::elements keys_viewviews::keys values_viewviews::values transform_viewviews::transform adjacent_viewviews::adjacent (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) stride_viewviews::stride (C++23)(C++23)	filter_viewviews::filter join_viewviews::join split_viewviews::split lazy_split_viewviews::lazy_split join_with_viewviews::join_with (C++23)(C++23) chunk_viewviews::chunk (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23)
Range adaptor objects
Range adaptor closure objects
Helper items
copyable-box	simple-view

 

std::ranges::take_view

Member functions

take_view::take_view (C++20)

take_view::base (C++20)

take_view::begin (C++20)

take_view::end (C++20)

take_view::size (C++20)

Deduction guides

Sentinel

take_view::sentinel::sentinel (C++20)

take_view::sentinel::base (C++20)

operator==(std::counted_iterator,take_view::sentinel) (C++20)

 

friend constexpr bool     operator==( const std::counted_iterator<ranges::iterator_t<Base>>& y,                 const /*sentinel*/& x );	(1)	(since C++20)
template< bool OtherC = !Const >     requires std::sentinel_for<ranges::sentinel_t<Base>,                                ranges::iterator_t</*add-const-if*/<OtherC, V>>> friend constexpr bool operator==( const std::counted_iterator<ranges::iterator_t<                                       /*add-const-if*/<OtherC, V>>>& y,                                   const /*sentinel*/& x );	(2)	(since C++20)

Compares a take_view::/*sentinel*/ with a std::counted_iterator (typically obtained from a call to take_view::begin).

Returns true if y points past the N-th element (where N is the number passed to the constructor of take_view), or if end of underlying view is reached.

The exposition-only alias template add-const-if is defined as template<bool C, class T> using /*add-const-if*/ = std::conditional_t<C, const T, T>;.

These functions are not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::ranges::take_view::sentinel<Const> is an associated class of the arguments.

The != operator is synthesized from operator==.

Parameters

y	-	std::counted_iterator to compare
x	-	sentinel to compare

Return value

y.count() == 0 || y.base() == x.end_, where end_ denotes the underlying sentinel.

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 3449	C++20	comparison between the iterator and the sentinel of differently const-qualified take_view was unsupported	made supported when possible