std::ranges::common_view<V>::size

From cppreference.com
< cpp‎ | ranges‎ | common view
 
 
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
 
 
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.

Equivalent to { return ranges::size(base_); }, where base_ is the underlying view.

Parameters

(none)

Return value

The number of elements.

Example

#include <ranges>
#include <string_view>
 
int main()
{
    constexpr static auto v1 = {1, 2, 3, 4, 5};
    constexpr auto common1 { v1 | std::views::common };
    static_assert(common1.size() == 5);
 
    constexpr auto take3 { v1 | std::views::reverse | std::views::take(3) };
    constexpr auto common2 { take3 | std::views::common };
    static_assert(common2.size() == 3);
 
    using namespace std::literals;
    constexpr static auto v2 = { "∧"sv, "∨"sv, "∃"sv, "∀"sv };
    static_assert(std::ranges::views::common(v2).size() == 4);
}

See also

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