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 |
10 | |
11 | // <tuple> |
12 | |
13 | // inline constexpr ignore-type ignore; |
14 | |
15 | #include <cassert> |
16 | #include <cstdint> |
17 | #include <tuple> |
18 | #include <type_traits> |
19 | |
20 | #include "test_macros.h" |
21 | |
22 | static_assert(std::is_trivially_copyable<decltype(std::ignore)>::value, "" ); |
23 | static_assert(std::is_trivially_default_constructible<decltype(std::ignore)>::value, "" ); |
24 | |
25 | #if TEST_STD_VER >= 17 |
26 | [[nodiscard]] constexpr int test_nodiscard() { return 8294; } |
27 | #endif |
28 | |
29 | TEST_CONSTEXPR_CXX14 bool test() { |
30 | { [[maybe_unused]] auto& ignore_v = std::ignore; } |
31 | |
32 | { // Test that std::ignore provides converting assignment. |
33 | auto& res = (std::ignore = 42); |
34 | static_assert(noexcept(res = (std::ignore = 42)), "Must be noexcept" ); |
35 | assert(&res == &std::ignore); |
36 | } |
37 | { // Test bit-field binding. |
38 | struct S { |
39 | unsigned int bf : 3; |
40 | }; |
41 | S s{.bf: 0b010}; |
42 | auto& res = (std::ignore = s.bf); |
43 | assert(&res == &std::ignore); |
44 | } |
45 | { // Test that std::ignore provides copy/move constructors |
46 | auto copy = std::ignore; |
47 | [[maybe_unused]] auto moved = std::move(copy); |
48 | } |
49 | { // Test that std::ignore provides copy/move assignment |
50 | auto copy = std::ignore; |
51 | copy = std::ignore; |
52 | auto moved = std::ignore; |
53 | moved = std::move(copy); |
54 | } |
55 | |
56 | #if TEST_STD_VER >= 17 |
57 | { std::ignore = test_nodiscard(); } |
58 | #endif |
59 | |
60 | return true; |
61 | } |
62 | |
63 | int main(int, char**) { |
64 | test(); |
65 | #if TEST_STD_VER >= 14 |
66 | static_assert(test(), "" ); |
67 | #endif |
68 | |
69 | return 0; |
70 | } |
71 | |