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

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 .

Customization point objects

The name views::zip denotes a customization point object , which is a const function object of a literal semiregular class type. For exposition purposes, the cv-unqualified version of its type is denoted as __zip_fn .

All instances of __zip_fn are equal. The effects of invoking different instances of type __zip_fn on the same arguments are equivalent, regardless of whether the expression denoting the instance is an lvalue or rvalue, and is const-qualified or not (however, a volatile-qualified instance is not required to be invocable). Thus, views::zip can be copied freely and its copies can be used interchangeably.

Given a set of types Args... , if std:: declval < Args > ( ) ... meet the requirements for arguments to views::zip above, __zip_fn models

• std:: invocable < __zip_fn, Args... > ,
• std:: invocable < const __zip_fn, Args... > ,
• std:: invocable < __zip_fn & , Args... > , and
• std:: invocable < const __zip_fn & , Args... > .
  

Otherwise, no function call operator of __zip_fn participates in overload resolution.

Data members

Member functions

Deduction guides

Nested classes

Helper templates

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

Notes

Example

#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);
}

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