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std::ranges::drop_view::size(3) | C++ Standard Libary | std::ranges::drop_view::size(3) |
NAME¶
std::ranges::drop_view::size - std::ranges::drop_view::size
Synopsis¶
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.
Let base_ be the underlying view, count_ be the stored count (usually the
number
passed to the constructor, or 0 if *this is default constructed). Equivalent
to
const auto s = ranges::size(base_);
const auto c = static_cast<decltype(s)>(count_);
return s < c ? 0 : s - c;
Parameters¶
(none)
Return value¶
The number of elements.
Example¶
// Run this code
#include <array>
#include <ranges>
int main()
{
constexpr std::array a{42, 43, 44};
static_assert(std::ranges::drop_view{std::views::all(a), 0}.size() == 3);
static_assert(std::ranges::drop_view{std::views::all(a), 1}.size() == 2);
static_assert(std::ranges::drop_view{std::views::all(a), 2}.size() == 1);
static_assert(std::ranges::drop_view{std::views::all(a), 3}.size() == 0);
static_assert(std::ranges::drop_view{std::views::all(a), 4}.size() == 0);
}
See also¶
ranges::size returns an integer equal to the size of a range
(C++20) (customization point object)
ranges::ssize returns a signed integer equal to the size of a range
(C++20) (customization point object)
2024.06.10 | http://cppreference.com |