std::ranges::views::zip_transform, std::ranges::zip_transform_view - cppreference.com (original) (raw)

std::ranges::zip_transform_view

Defined in header
template< std::move_constructible F, ranges::input_range... Views > requires (ranges::view<Views> && ...) && (sizeof...(Views) > 0) && std::is_object_v<F> && std::regular_invocable< F&, ranges::range_reference_t<Views>...> && /can-reference/<std::invoke_result_t< F&, ranges::range_reference_t<Views>...>> class zip_transform_view : public ranges::view_interface<zip_transform_view<F, Views...>>	(1)	(since C++23)
namespace views { inline constexpr /unspecified/ zip_transform = /unspecified/; }	(2)	(since C++23)
Call signature
template< class F, ranges::viewable_range... Rs > requires /* see below */ constexpr auto zip_transform( F&& f, Rs&&... rs );		(since C++23)

zip_transform_view is a range adaptor that takes an invocable object and one or more views, and produces a view whose _i_th element is the result of applying the invocable object to the _i_th elements of all views.
A type T models the exposition-only concept /*can-reference*/ if and only if T& is a valid type.
views::zip_transform is a customization point object.

When calling with one argument f, let FD be std::decay_t<decltype(f)>, if:

FD models copy_constructible,
FD& models regular_invocable, and
std::invoke_result_t<FD&> is an object type,

then views::zip_transform(f) is expression-equivalent to ((void)f, auto(views::empty<std::decay_t<std::invoke_result_t<FD&>>>)). Otherwise, the call to views::zip_transform is ill-formed.

When calling with more than one arguments f and rs..., views::zip_transform(f, rs...) is expression-equivalent to ranges::zip_transform_view(f, rs...).

zip_transform_view models the concepts random_access_range, bidirectional_range, forward_range, input_range, common_range, and sized_range when the underlying ranges::zip_view<Views...> models respective concepts.

1 Customization point objects
2 Member functions
- 2.1 Inherited from std::ranges::view_interface
3 Deduction guides
4 Member types
5 Data members
6 Nested classes
7 Notes
8 Example
9 See also

Customization point objects

The name views::zip_transform denotes a customization point object, which is a const function object of a literal semiregular class type. See CustomizationPointObject for details.

[edit] Member functions

(constructor)	constructs a zip_transform_view (public member function) [edit]
begin	returns an iterator to the beginning (public member function) [edit]
end	returns an iterator or a sentinel to the end (public member function) [edit]
size	returns the number of elements, provided only if each underlying (adapted) range satisfies sized_range (public member function) [edit]
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) [edit]
cbegin(C++23)	returns a constant iterator to the beginning of the range (public member function of std::ranges::view_interface) [edit]
cend(C++23)	returns a sentinel for the constant iterator of the range (public member function of std::ranges::view_interface) [edit]
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) [edit]
front	returns the first element in the derived view, provided if it satisfies forward_range (public member function of std::ranges::view_interface) [edit]
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) [edit]
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) [edit]

[edit] Deduction guides

[edit] Member types

[edit] Data members

Member object	Definition
zip_ (private)	An underlying view object of type InnerView(exposition-only member object*)
fun_ (private)	A wrapped invocable object of type movable-box(exposition-only member object*)

[edit] Nested classes

| | the iterator type(exposition-only member class template*) | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | the sentinel type used when the underlying zip_view is not a common_range(exposition-only member class template*) |

[edit] Notes

Feature-test macro	Value	Std	Feature
__cpp_lib_ranges_zip	202110L	(C++23)	ranges::zip_view,std::ranges::zip_transform_view,ranges::adjacent_view,ranges::adjacent_transform_view

[edit] Example

#include #include #include #include #include void print(auto const rem, auto const& r) { std::cout << rem << '{'; for (char o[]{0,' ',0}; auto const& e : r) std::cout << o << e, *o = ','; std::cout << "}\n"; } int main() { auto v1 = std::vector{1, 2, 3}; auto v2 = std::list{1, 2, 3, 4}; auto v3 = std::to_array({1, 2, 3, 4, 5}); auto add = [](auto a, auto b, auto c) { return a + b + c; }; auto sum = std::views::zip_transform(add, v1, v2, v3); print("v1: ", v1); print("v2: ", v2); print("v3: ", v3); print("sum: ", sum); }

Output:

v1: {1, 2, 3} v2: {1, 2, 3, 4} v3: {1, 2, 3, 4, 5} sum: {3, 6, 9}