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, c++20 |
10 | |
11 | // |
12 | // constexpr expected(); |
13 | |
14 | // Constraints: is_default_constructible_v<T> is true. |
15 | // |
16 | // Effects: Value-initializes val. |
17 | // Postconditions: has_value() is true. |
18 | // |
19 | // Throws: Any exception thrown by the initialization of val. |
20 | |
21 | #include <cassert> |
22 | #include <expected> |
23 | #include <type_traits> |
24 | |
25 | #include "test_macros.h" |
26 | #include "../../types.h" |
27 | |
28 | struct NoDedefaultCtor { |
29 | NoDedefaultCtor() = delete; |
30 | }; |
31 | |
32 | // Test constraints |
33 | static_assert(std::is_default_constructible_v<std::expected<int, int>>); |
34 | static_assert(!std::is_default_constructible_v<std::expected<NoDedefaultCtor, int>>); |
35 | |
36 | struct MyInt { |
37 | int i; |
38 | friend constexpr bool operator==(const MyInt&, const MyInt&) = default; |
39 | }; |
40 | |
41 | template <class T, class E> |
42 | constexpr void testDefaultCtor() { |
43 | std::expected<T, E> e; |
44 | assert(e.has_value()); |
45 | assert(e.value() == T()); |
46 | } |
47 | |
48 | template <class T> |
49 | constexpr void testTypes() { |
50 | testDefaultCtor<T, bool>(); |
51 | testDefaultCtor<T, int>(); |
52 | testDefaultCtor<T, NoDedefaultCtor>(); |
53 | } |
54 | |
55 | constexpr bool test() { |
56 | testTypes<int>(); |
57 | testTypes<MyInt>(); |
58 | testTypes<TailClobberer<0>>(); |
59 | return true; |
60 | } |
61 | |
62 | void testException() { |
63 | #ifndef TEST_HAS_NO_EXCEPTIONS |
64 | struct Throwing { |
65 | Throwing() { throw Except{}; }; |
66 | }; |
67 | |
68 | try { |
69 | std::expected<Throwing, int> u; |
70 | assert(false); |
71 | } catch (Except) { |
72 | } |
73 | #endif // TEST_HAS_NO_EXCEPTIONS |
74 | } |
75 | |
76 | int main(int, char**) { |
77 | test(); |
78 | static_assert(test()); |
79 | testException(); |
80 | return 0; |
81 | } |
82 | |