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 | // <iterator> |
12 | |
13 | // move_sentinel |
14 | |
15 | // template<class S2> |
16 | // requires assignable_from<S&, const S2&> |
17 | // constexpr move_sentinel& operator=(const move_sentinel<S2>& s); |
18 | |
19 | #include <cassert> |
20 | #include <concepts> |
21 | #include <iterator> |
22 | #include <type_traits> |
23 | |
24 | struct NonAssignable { |
25 | NonAssignable& operator=(int i); |
26 | }; |
27 | static_assert(std::semiregular<NonAssignable>); |
28 | static_assert(std::is_assignable_v<NonAssignable, int>); |
29 | static_assert(!std::assignable_from<NonAssignable, int>); |
30 | |
31 | constexpr bool test() |
32 | { |
33 | // Assigning from an lvalue. |
34 | { |
35 | std::move_sentinel<int> m(42); |
36 | std::move_sentinel<long> m2; |
37 | m2 = m; |
38 | assert(m2.base() == 42L); |
39 | } |
40 | |
41 | // Assigning from an rvalue. |
42 | { |
43 | std::move_sentinel<long> m2; |
44 | m2 = std::move_sentinel<int>(43); |
45 | assert(m2.base() == 43L); |
46 | } |
47 | |
48 | // SFINAE checks. |
49 | { |
50 | static_assert( std::is_assignable_v<std::move_sentinel<int>, std::move_sentinel<long>>); |
51 | static_assert(!std::is_assignable_v<std::move_sentinel<int*>, std::move_sentinel<const int*>>); |
52 | static_assert( std::is_assignable_v<std::move_sentinel<const int*>, std::move_sentinel<int*>>); |
53 | static_assert(!std::is_assignable_v<std::move_sentinel<NonAssignable>, std::move_sentinel<int>>); |
54 | } |
55 | return true; |
56 | } |
57 | |
58 | int main(int, char**) |
59 | { |
60 | test(); |
61 | static_assert(test()); |
62 | |
63 | return 0; |
64 | } |
65 | |