std::ranges::views::slide, std::ranges::slide_view

 

C++

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Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Diagnostics library

Memory management library

Metaprogramming library (C++11)

General utilities library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library (C++17)

Concurrency support library (C++11)

Execution control library (C++26)

Technical specifications

Symbols index

External libraries

 

Ranges library

Range access begin cbegin      end cend rbegin crbegin      rend crend size ssize      data cdata reserve_hint (C++26)         empty

Range conversions std::from_range_t std::from_range (C++23)(C++23)         to (C++23)

Dangling iterator handling dangling borrowed_iterator_t borrowed_subrange_t

Range primitives
range_size_trange_difference_trange_value_t      elements_of (C++23)	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (C++23)(C++23)	range_reference_trange_const_reference_trange_rvalue_reference_trange_common_reference_t (C++23)

Range concepts
range borrowed_range      common_range	sized_range viewable_range      view	input_range output_range forward_range	bidirectional_range      random_access_range contiguous_range	approximately_sized_range (C++26) constant_range (C++23) sized-random-access-range (C++26)

Views
view_interface	subrange

Range factories
empty_viewviews::empty	single_viewviews::single	basic_istream_viewviews::istream	iota_viewviews::iota views::indices (C++26)	repeat_viewviews::repeat (C++23)(C++23)

Range adaptors
views::all_tviews::all as_rvalue_viewviews::as_rvalue (C++23)(C++23)     filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while common_viewviews::common views::counted as_input_viewviews::as_input (C++26)(C++26)	ref_view drop_viewviews::drop drop_while_viewviews::drop_while lazy_split_viewviews::lazy_split split_viewviews::split join_viewviews::join join_with_viewviews::join_with (C++23)(C++23) concat_viewviews::concat (C++26)(C++26) cache_latest_viewviews::cache_latest (C++26)(C++26)	owning_view reverse_viewviews::reverse as_const_viewviews::as_const (C++23)(C++23) elements_viewviews::elements keys_viewviews::keys values_viewviews::values enumerate_viewviews::enumerate (C++23)(C++23) zip_viewviews::zip (C++23)(C++23) zip_transform_viewviews::zip_transform (C++23)(C++23)	adjacent_viewviews::adjacent (C++23)(C++23) views::pairwise (C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23) views::pairwise_transform (C++23) chunk_viewviews::chunk (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23) stride_viewviews::stride (C++23)(C++23) cartesian_product_viewviews::cartesian_product (C++23)(C++23)

Range generators std::generator (C++23)

Range adaptor closure objects range_adaptor_closure (C++23)

Range adaptor objects

Helper items
copyable-box movable-box (until C++23)    (C++23)	simple-view non-propagating-cache

 

std::ranges::slide_view

Member functions

slide_view::slide_view

slide_view::begin

slide_view::end

slide_view::size

slide_view::reserve_hint (C++26)

Deduction guides

Iterator

Member functions

slide_view::iterator::iterator

slide_view::iterator::operator*

slide_view::iterator::operator[]

slide_view::iterator::operator++ slide_view::iterator::operator++(int) slide_view::iterator::operator-- slide_view::iterator::operator--(int) slide_view::iterator::operator+= slide_view::iterator::operator-=

Non-member functions

operator==(slide_view::iterator) operator<(slide_view::iterator) operator>(slide_view::iterator) operator<=(slide_view::iterator) operator>=(slide_view::iterator) operator<=>(slide_view::iterator)

operator+(slide_view::iterator) operator-(slide_view::iterator)

Sentinel

Member functions

slide_view::sentinel::sentinel

Non-member functions

operator==(slide_view::iterator,slide_view::sentinel)

operator-(slide_view::iterator,slide_view::sentinel)

 

Defined in header <ranges>
template< ranges::forward_range V > requires ranges::view<V> class slide_view : public ranges::view_interface<slide_view<V>>	(1)	(since C++23)
namespace views { inline constexpr /* unspecified */ slide = /* unspecified */; }	(2)	(since C++23)
Call signature
template< ranges::viewable_range R > constexpr ranges::view auto slide( R&& r, ranges::range_difference_t<R> n );		(since C++23)
template< class DifferenceType > constexpr /* range adaptor object */ slide( DifferenceType&& n );		(since C++23)
Helper concepts
template< class V > concept /*slide-caches-nothing*/ = ranges::random_access_range<V> && ranges::sized_range<V>;	(3)	(exposition only*)
template< class V > concept /*slide-caches-last*/ = !/*slide-caches-nothing*/<V> && ranges::bidirectional_range<V> && ranges::common_range<V>;	(4)	(exposition only*)
template< class V > concept /*slide-caches-first*/ = !/*slide-caches-nothing*/<V> && !/*slide-caches-last*/<V>;	(5)	(exposition only*)

1) slide_view is a range adaptor that takes a view and a number n and produces a view whose mth element (a “window”) is a view over [m, m + n - 1] elements of the original view.

Let s be the size of the original view. Then the size of produced view is:

• s - n + 1, if s >= n,
• 0 otherwise, and the resulting view is empty.

2) The name views::slide denotes a RangeAdaptorObject. Given subexpressions e and n, the expression views::slide(e, n) is expression-equivalent to slide_view(e, n).

If n is not greater than 0, the behavior is undefined.

slide_view always models forward_range, and models bidirectional_range, random_access_range, or sized_range if adapted view type models the corresponding concept.

Data members

Member	Description
V base_	the underlying view (exposition-only member object*)
ranges::range_difference_t<V> n_	the “window” size (exposition-only member object*)
non-propagating-cache<ranges::iterator_t<V>> cached_begin_ (present only if V models the slide-caches-first)	an object that caches the result of begin() (exposition-only member object*)
non-propagating-cache<ranges::iterator_t<V>> cached_end_ (present only if V models the slide-caches-last)	an object that caches the result of end() (exposition-only member object*)

Member functions

(constructor)	constructs a slide_view (public member function)
base	returns a copy of the underlying (adapted) view (public member function)
begin	returns an iterator to the beginning (public member function)
end	returns an iterator or a sentinel to the end (public member function)
size	returns the number of elements, provided only if the underlying (adapted) range satisfies sized_range (public member function)
reserve_hint (C++26)	returns the approximate size of the resulting approximately_sized_range (public member function)
Inherited from std::ranges::view_interface
empty	returns whether the derived view is empty, provided only if it satisfies sized_range or forward_range (public member function of std::ranges::view_interface<D>)
cbegin (C++23)	returns a constant iterator to the beginning of the range (public member function of std::ranges::view_interface<D>)
cend (C++23)	returns a sentinel for the constant iterator of the range (public member function of std::ranges::view_interface<D>)
operator bool	returns whether the derived view is not empty, provided only if ranges::empty is applicable to it (public member function of std::ranges::view_interface<D>)
front	returns the first element in the derived view, provided if it satisfies forward_range (public member function of std::ranges::view_interface<D>)
back	returns the last element in the derived view, provided only if it satisfies bidirectional_range and common_range (public member function of std::ranges::view_interface<D>)
operator[]	returns the nth element in the derived view, provided only if it satisfies random_access_range (public member function of std::ranges::view_interface<D>)

Nested classes

iterator (C++23)	the iterator type (exposition-only member class template*)
sentinel (C++23)	the sentinel type used when slide_view is not a common_range (exposition-only member class template*)

Helper templates

template< class V > constexpr bool ranges::enable_borrowed_range<slide_view<V>> = ranges::enable_borrowed_range<V>;		(since C++23)

This specialization of ranges::enable_borrowed_range makes slide_view satisfy borrowed_range when the underlying view satisfies it.

Notes

There are similarities between ranges::adjacent_view and ranges::slide_view:

• Both create “sliding window” of size N.
• Both have the same size S - N + 1, where S is the size of an adapted view such that S >= N > 0.

The following table shows the differences between these adaptors:

View adaptor	value_type	The window size N
ranges::adjacent_view	std::tuple	A template parameter
ranges::slide_view	ranges::range	A runtime argument

Feature-test macro	Value	Std	Feature
__cpp_lib_ranges_slide	202202L	(C++23)	std::ranges::slide_view

Example

Run this code

#include <initializer_list>
#include <print>
#include <ranges>

int main()
{
    const auto v = {1, 2, 3, 4, 5, 6};
    
    std::println("All sliding windows of width:");
    for (const unsigned width : std::views::iota(1U, 1U + v.size()))
    {
        auto const windows = v | std::views::slide(width);
        std::println("W = {}: {}", width, windows);
    }
}

Output:

All sliding windows of width:
W = 1: [[1], [2], [3], [4], [5], [6]]
W = 2: [[1, 2], [2, 3], [3, 4], [4, 5], [5, 6]]
W = 3: [[1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6]]
W = 4: [[1, 2, 3, 4], [2, 3, 4, 5], [3, 4, 5, 6]]
W = 5: [[1, 2, 3, 4, 5], [2, 3, 4, 5, 6]]
W = 6: [[1, 2, 3, 4, 5, 6]]

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 3848	C++23	slide_view does not provide a base() accessor	added

References

• C++23 standard (ISO/IEC 14882:2024):

• 26.7.29 Slide view [range.slide]

See also

ranges::adjacent_viewviews::adjacent (C++23)	a view consisting of tuples of references to adjacent elements of the adapted view (class template) (range adaptor object)
ranges::chunk_viewviews::chunk (C++23)	a range of views that are N-sized non-overlapping successive chunks of the elements of another view (class template) (range adaptor object)