std::ranges::views::slide, std::ranges::slide_view
| Defined in header <ranges>
|
||
| template< ranges::forward_range V > requires ranges::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*/ = |
(3) | (exposition only*) |
template< class V > concept /*slide-caches-last*/ = |
(4) | (exposition only*) |
template< class V > concept /*slide-caches-first*/ = |
(5) | (exposition only*) |
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 the mth through (m + n - 1)th elements of the original view.- s - n + 1, if s >= n,
- 0 otherwise, and the resulting view is empty.
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 object | Definition |
base_ (private)
|
The underlying view of type V.(exposition-only member object*) |
n_ (private)
|
The "window size" of type ranges::range_difference_t<V>. (exposition-only member object*) |
cached_begin_ (private) (present only if V models the slide-caches-first)
|
An optional-like object. (exposition-only member object*) |
cached_end_ (private) (present only if V models the slide-caches-last)
|
An optional-like object. (exposition-only member object*) |
Member functions
constructs a slide_view (public member function) | |
| returns an iterator to the beginning (public member function) | |
| returns an iterator or a sentinel to the end (public member function) | |
returns the number of elements. Provided only if the underlying (adapted) range satisfies sized_range. (public member function) | |
Inherited from std::ranges::view_interface | |
returns whether the derived view is empty. Provided if it satisfies sized_range or forward_range. (public member function of std::ranges::view_interface<D>) | |
| (C++23) |
returns a constant iterator to the beginning of the range. (public member function of std::ranges::view_interface<D>) |
| (C++23) |
returns a sentinel for the constant iterator of the range. (public member function of std::ranges::view_interface<D>) |
| returns whether the derived view is not empty. Provided if ranges::empty is applicable to it. (public member function of std::ranges::view_interface<D>) | |
returns the first element in the derived view. Provided if it satisfies forward_range. (public member function of std::ranges::view_interface<D>) | |
returns the last element in the derived view. Provided if it satisfies bidirectional_range and common_range. (public member function of std::ranges::view_interface<D>) | |
returns the nth element in the derived view. Provided if it satisfies random_access_range. (public member function of std::ranges::view_interface<D>) | |
Deduction guides
Nested classes
| (C++23) |
the iterator type (exposition-only member class template*) |
| (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>> = |
(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 a "sliding window" of size
N. - Both have the same size
S - N + 1, whereSis the size of an adaptedviewsuch thatS >= 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
#include <algorithm> #include <iostream> #include <ranges> auto print_subrange = [](std::ranges::viewable_range auto&& r) { std::cout << '['; for (char space[]{0,0}; auto elem : r) std::cout << space << elem, *space = ' '; std::cout << "] "; }; int main() { const auto v = {1, 2, 3, 4, 5, 6}; std::cout << "All sliding windows of width:\n"; for (const unsigned width : std::views::iota(1U, 1U + v.size())) { auto const windows = v | std::views::slide(width); std::cout << "W = " << width << ": "; std::ranges::for_each(windows, print_subrange); std::cout << '\n'; } }
Output:
All sliding windows of width W: 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]
References
- C++23 standard (ISO/IEC 14882:2024):
- 26.7.29 Slide view [range.slide]
See also
a view consisting of tuples of references to adjacent elements of the adapted view(class template) (range adaptor object) | |
a range of views that are N-sized non-overlapping successive chunks of the elements of another view(class template) (range adaptor object) |