1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14, c++17
10
11// std::ranges::dangling;
12
13#include <ranges>
14
15#include <concepts>
16#include <type_traits>
17
18static_assert(std::is_empty_v<std::ranges::dangling>);
19
20template<int> struct S { };
21static_assert(std::is_nothrow_constructible_v<std::ranges::dangling>);
22static_assert(std::is_nothrow_constructible_v<std::ranges::dangling, S<0>>);
23static_assert(std::is_nothrow_constructible_v<std::ranges::dangling, S<0>, S<1>>);
24static_assert(std::is_nothrow_constructible_v<std::ranges::dangling, S<0>, S<1>, S<2>>);
25
26constexpr bool test_dangling() {
27 [[maybe_unused]] auto a = std::ranges::dangling();
28 [[maybe_unused]] auto b = std::ranges::dangling(S<0>());
29 [[maybe_unused]] auto c = std::ranges::dangling(S<0>(), S<1>());
30 [[maybe_unused]] auto d = std::ranges::dangling(S<0>(), S<1>(), S<2>());
31 return true;
32}
33
34int main(int, char**) {
35 static_assert(test_dangling());
36 test_dangling();
37 return 0;
38}
39

source code of libcxx/test/std/ranges/range.utility/range.dangling/dangling.pass.cpp