FreeBSD Manual Pages
std::ranges...e_view::size(3) C++ Standard Libarystd::ranges...e_view::size(3) NAME std::ranges::slide_view::size - std::ranges::slide_view::size Synopsis constexpr auto size() (since C++23) requires ranges::sized_range<V>; constexpr auto size() const (since C++23) requires ranges::sized_range<const V>; Returns the number of elements. Let base_ and n_ be the underlying view and "window size" respec- tively. Equivalent to: auto sz = ranges::distance(base_) - n_ + 1; if (sz < 0) sz = 0; return __to_unsigned_like(sz); Parameters (none) Return value The number of elements. Equals to 0, if the number of elements (ranges::size(base_)) in underlying view base_ is less than "window size" n_. Example // Run this code #include <forward_list> #include <iostream> #include <list> #include <ranges> int main() { constexpr static auto v = {1, 2, 3, 4, 5, 6}; constexpr int width1{4}; constexpr auto view1{std::views::slide(v, width1)}; static_assert(view1.size() == 3); static_assert(view1.size() == (v.size() - width1 + 1)); constexpr int width2{8}; constexpr auto view2{std::views::slide(v, width2)}; // window is too wide, so view2 has no elements: static_assert(view2.size() == 0); std::forward_list forward_list = v; const auto view3{std::views::slide(forward_list, width1)}; // auto x = view3.size(); // error: sized_range constraint is not satisfied std::list list = v; const auto view4{std::views::slide(list, width1)}; std::cout << view4.size() << '\n'; // prints 3 } Output: 3 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) http://cppreference.com 2024.06.10 std::ranges...e_view::size(3)
NAME | Synopsis | Parameters | Return value | Example | Output: | See also
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=std::ranges::slide_view::size&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>