Namespaces
Variants
Views
Actions

std::ranges::elements_view<V,N>::elements_view

From cppreference.com
 
 
Ranges library
Range access
Range conversions
(C++23)
Range primitives



Dangling iterator handling
Range concepts
Views

Factories




Adaptors
Range adaptor objects
Range adaptor closure objects
Helper items
 
 
elements_view() requires std::default_initializable<V> = default;
(1) (since C++20)
constexpr elements_view( V base );
(2) (since C++20)

Constructs an elements_view.

1) Default constructor. Value-initializes the underlying view. After construction, base() returns a copy of V().
2) Initializes the underlying view with std::move(r).

[edit] Parameters

base - the underlying view

[edit] Example

#include <iostream>
#include <ranges>
#include <tuple>
#include <array>
using namespace std::literals;
 
int main()
{
    const std::array<std::tuple<int, char, std::string>, 2> vt {
        std::tuple{1, 'A', "α"s},
        std::tuple{2, 'B', "β"s},
    };
 
    [[maybe_unused]] 
    auto empty = std::views::elements<0>;
 
    auto ev0 = std::views::elements<0>(vt);
    auto ev1 = std::views::elements<1>(vt);
    auto ev2 = std::views::elements<2>(vt);
 
    for (auto const& e: ev0) { std::cout << e << ' '; }
    std::cout << '\n';
    for (auto const& e: ev1) { std::cout << e << ' '; }
    std::cout << '\n';
    for (auto const& e: ev2) { std::cout << e << ' '; }
    std::cout << '\n';
}

Output:

1 2
A B
α β