NAME¶

std::ranges::views::zip,std::ranges::zip_view - std::ranges::views::zip,std::ranges::zip_view

Synopsis¶

Defined in header <ranges>
template< ranges::input_range... Views >

requires (ranges::view<Views> && ...) && (sizeof...(Views) >
0) (1) (since C++23)
class zip_view

: public ranges::view_interface<zip_view<Views...>>
namespace views {

inline constexpr /*unspecified*/ zip = /*unspecified*/; (2) (since C++23)

}
Call signature
template< ranges::viewable_range... Rs >

requires /* see below */ (since C++23)

constexpr auto zip( Rs&&... rs );

1) zip_view is a range adaptor that takes one or more views, and produces a view
whose ith element is a tuple-like value consisting of the i^th elements of all
views. The size of produced view is the minimum of sizes of all adapted views.
2) views::zip is a customization point object.

When calling with no argument, views::zip() is expression-equivalent to
auto(views::empty<std::tuple<>>).

Otherwise, views::zip(rs...) is expression-equivalent to
ranges::zip_view<views::all_t<decltype((rs))>...>(rs...).

zip_view always models input_range, and models forward_range, bidirectional_range,
random_access_range, or sized_range if all adapted view types model the
corresponding concept.

zip_view models common_range if

* sizeof...(Views) is equal to 1, and the only adapted view type models
common_range, or
* at least one adapted view type does not model bidirectional_range, and every
adapted view type models common_range, or
* every adapted view type models both random_access_range and sized_range.

Member functions¶

constructor constructs a zip_view
(C++23) (public member function)
begin returns an iterator to the beginning
(C++23) (public member function)
end returns an iterator or a sentinel to the end
(C++23) (public member function)
size returns the number of elements. Provided only if each underlying
(C++23) (adapted) range satisfies sized_range.
(public member function)
Inherited from std::ranges::view_interface
empty returns whether the derived view is empty. Provided if it satisfies
(C++20) sized_range or forward_range.
(public member function of std::ranges::view_interface<D>)
cbegin returns a constant iterator to the beginning of the range.
(C++23) (public member function of std::ranges::view_interface<D>)
cend returns a sentinel for the constant iterator of the range.
(C++23) (public member function of std::ranges::view_interface<D>)
operator bool returns whether the derived view is not empty. Provided if
(C++20) 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
(C++20) satisfies forward_range.
(public member function of std::ranges::view_interface<D>)
back returns the last element in the derived view. Provided if it satisfies
(C++20) bidirectional_range and common_range.
(public member function of std::ranges::view_interface<D>)
operator[] returns the n^th element in the derived view. Provided if it satisfies
(C++20) random_access_range.
(public member function of std::ranges::view_interface<D>)

Deduction guides

Nested classes

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

Helper templates

template< class... Views >

inline constexpr bool (since C++23)
enable_borrowed_range<ranges::zip_view<Views...>> =

(ranges::enable_borrowed_range<Views> && ...);

This specialization of ranges::enable_borrowed_range makes zip_view satisfy
borrowed_range when each underlying view satisfies it.

Notes¶

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

Example¶

// Run this code

#include <array>
#include <iostream>
#include <list>
#include <ranges>
#include <string>
#include <tuple>
#include <vector>

void print(auto const rem, auto const& range)
{
for (std::cout << rem; auto const& elem : range)
std::cout << elem << ' ';
std::cout << '\n';
}

int main()
{
auto x = std::vector{1, 2, 3, 4};
auto y = std::list<std::string>{"α", "β", "γ", "δ", "ε"};
auto z = std::array{'A', 'B', 'C', 'D', 'E', 'F'};

print("Source views:", "");
print("x: ", x);
print("y: ", y);
print("z: ", z);

print("\nzip(x,y,z):", "");

for (std::tuple<int&, std::string&, char&> elem : std::views::zip(x, y, z))
{
std::cout << std::get<0>(elem) << ' '
<< std::get<1>(elem) << ' '
<< std::get<2>(elem) << '\n';

std::get<char&>(elem) += ('a' - 'A'); // modifies the element of z
}

print("\nAfter modification, z: ", z);
}

Output:¶

Source views:
x: 1 2 3 4
y: α β γ δ ε
z: A B C D E F

zip(x,y,z):
1 α A
2 β B
3 γ C
4 δ D

After modification, z: a b c d E F

See also¶

ranges::zip_transform_view a view consisting of tuples of results of application of
views::zip_transform a transformation function to corresponding elements of
(C++23) the adapted views
(class template) (customization point object)
ranges::elements_view takes a view consisting of tuple-like values and a number
views::elements N and produces a view of N^th element of each tuple
(C++20) (class template) (range adaptor object)