xref: /llvm-project/libcxx/test/std/ranges/range.utility/range.dangling/dangling.pass.cpp (revision b8cb1dc9ea87faa8e8e9ab7a31710a8c0bb8b084)
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 
18 static_assert(std::is_empty_v<std::ranges::dangling>);
19 
20 template<int> struct S { };
21 static_assert(std::is_nothrow_constructible_v<std::ranges::dangling>);
22 static_assert(std::is_nothrow_constructible_v<std::ranges::dangling, S<0>>);
23 static_assert(std::is_nothrow_constructible_v<std::ranges::dangling, S<0>, S<1>>);
24 static_assert(std::is_nothrow_constructible_v<std::ranges::dangling, S<0>, S<1>, S<2>>);
25 
test_dangling()26 constexpr 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 
main(int,char **)34 int main(int, char**) {
35   static_assert(test_dangling());
36   test_dangling();
37   return 0;
38 }
39