Defined in header <ranges> | ||
|---|---|---|
template< ranges::forward_range V, std::move_constructible F, std::size_t N >
requires ranges::view<V> && (N > 0) && std::is_object_v<F> &&
std::regular_invocable<F&, __REPEAT(ranges::range_reference_t<V>, N)...> &&
__can_reference<std::invoke_result_t<F&,
__REPEAT(ranges::range_reference_t<V>, N)...>>
class adjacent_transform_view :
public ranges::view_interface<adjacent_transform_view<V, F, N>>
| (1) | (since C++23) |
namespace views {
template< std::size_t N >
inline constexpr /* unspecified */ adjacent_transform = /* unspecified */;
}
| (2) | (since C++23) |
namespace views {
inline constexpr auto pairwise_transform = adjacent_transform<2>;
}
| (3) | (since C++23) |
| Call signature | ||
template< ranges::viewable_range R, class F >
requires /* see below */
constexpr ranges::view auto adjacent_transform<N>( R&& r, F&& fun );
| (since C++23) | |
template< class F > constexpr /*range adaptor closure*/ adjacent_transform<N>( F&& fun ); | (since C++23) |
adjacent_transform_view is a range adaptor that takes a view and an invocable object fun, and produces a view whose ith element is a value that is the result of applying fun to each element in [i, i + N) of the original view. F always has arity N.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.views::adjacent_transform<N> denotes a RangeAdaptorObject. Given subexpressions e and f, and a constant expression N, the expression views::adjacent_transform<N>(e, f) is expression-equivalent to: ((void)e, views::zip_transform(f)), if N is equal to 0 (except that the evaluations of e and f are indeterminately sequenced), adjacent_transform_view<views::all_t<decltype((e))>, std::decay_t<decltype((f))>, N>(e, f) otherwise.
adjacent_transform_view always models forward_range, and models bidirectional_range, random_access_range, or sized_range, if adapted view type models the corresponding concept.
Typical implementations of adjacent_transform_view hold two non-static data members:
fun_ of type __movable_box<F>, inner_ of type ranges::adjacent_view<V,N> These names are for exposition only.
|
(C++23) | constructs a adjacent_transform_view (public member function) |
|
(C++23) | returns an iterator to the beginning (public member function) |
|
(C++23) | returns an iterator or a sentinel to the end (public member function) |
|
(C++23) | returns the number of elements. Provided only if the underlying (adapted) range satisfies sized_range. (public member function) |
Inherited from |
|
|
(C++20) | 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>) |
|
(C++20) | 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>) |
|
(C++20) | returns the first element in the derived view. Provided if it satisfies forward_range. (public member function of std::ranges::view_interface<D>) |
|
(C++20) | 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>) |
|
(C++20) | returns the nth element in the derived view. Provided if it satisfies random_access_range. (public member function of std::ranges::view_interface<D>) |
(none).
| Member type | Definition |
|---|---|
InnerView (private) | ranges::adjacent_view<V, N>. The name is for exposition only. |
inner_iterator (private) |
|
inner_sentinel (private) |
|
|
(C++23) | the iterator type (exposition-only member class template) |
|
(C++23) | the sentinel type used when adjacent_transform_view is not a common_range (exposition-only member class template) |
| Feature-test macro | Value | Std | Comment |
|---|---|---|---|
__cpp_lib_ranges_zip | 202110L | (C++23) |
|
A link to test: Compiler Explorer/g++-13.
#include <array>
#include <iostream>
#include <ranges>
int main()
{
constexpr static auto source = {1, 2, 3, 4, 5, 6};
constexpr int window {3};
auto Fun = [](auto... ints) { return (... + ints); };
// Alternatively, the Fun could be any ternary (if window == 3) callable, e.g.:
// auto Fun = [](int x, int y, int z) { return x + y + z; };
constexpr auto view = source | std::views::adjacent_transform< window >(Fun);
static_assert(
view.size() == (source.size() - window + 1)
and
std::array{view[0], view[1], view[2], view[3]} == std::array{6, 9, 12, 15}
);
for (int x : view)
std::cout << x << ' ';
std::cout << '\n';
}Output:
6 9 12 15
|
(C++23) | a view consisting of tuples of references to adjacent elements of the adapted view (class template) (range adaptor object) |
|
(C++20) | a view of a sequence that applies a transformation function to each element (class template) (range adaptor object) |
|
(C++23) | a view consisting of tuples of results of application of a transformation function to corresponding elements of the adapted views (class template) (customization point object) |
|
(C++20) | applies a function to a range of elements (niebloid) |
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