std::ranges::take_view<V>::size

< cpp‎ | ranges‎ | take view
constexpr auto size() requires ranges::sized_range<V>;
 (1) (since C++20)
constexpr auto size() const requires ranges::sized_range<const V>;
 (2) (since C++20)

Returns the number of elements, which is the smaller of the count passed to the constructor and the size of the underlying view.

Let base_ be the underlying view, count_ be the number passed to the constructor (​0​ if default constructed). Equivalent to

auto n = ranges::size(base_);
return ranges::min(n, static_cast<decltype(n)>(count_));

Parameters

(none)

Return value

The number of elements.

Example

#include <ranges>
#include <iostream>
 
int main()
{
    constexpr int arr[] {1, 2, 3};
 
    for (int i = 0; i != 6; ++i) {
        const auto tv = std::ranges::take_view{arr, i};
        std::cout << tv.size() << ' ';
    }
}

Output:

0 1 2 3 3 3

See also

(C++20)
 returns an integer equal to the size of a range
(customization point object)
(C++20)
 returns a signed integer equal to the size of a range
(customization point object)