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
10 // <optional>
11 
12 // constexpr optional(nullopt_t) noexcept;
13 
14 #include <optional>
15 #include <type_traits>
16 #include <cassert>
17 
18 #include "archetypes.h"
19 
20 #include "test_macros.h"
21 
22 using std::optional;
23 using std::nullopt_t;
24 using std::nullopt;
25 
26 template <class Opt>
27 void
28 test_constexpr()
29 {
30     static_assert(std::is_nothrow_constructible<Opt, nullopt_t&>::value, "");
31     static_assert(std::is_trivially_destructible<Opt>::value, "");
32     static_assert(std::is_trivially_destructible<typename Opt::value_type>::value, "");
33 
34     constexpr Opt opt(nullopt);
35     static_assert(static_cast<bool>(opt) == false, "");
36 
37     struct test_constexpr_ctor
38         : public Opt
39     {
40         constexpr test_constexpr_ctor() {}
41     };
42 }
43 
44 template <class Opt>
45 void
46 test()
47 {
48     static_assert(std::is_nothrow_constructible<Opt, nullopt_t&>::value, "");
49     static_assert(!std::is_trivially_destructible<Opt>::value, "");
50     static_assert(!std::is_trivially_destructible<typename Opt::value_type>::value, "");
51     {
52     Opt opt(nullopt);
53     assert(static_cast<bool>(opt) == false);
54     }
55     {
56     const Opt opt(nullopt);
57     assert(static_cast<bool>(opt) == false);
58     }
59     struct test_constexpr_ctor
60         : public Opt
61     {
62         constexpr test_constexpr_ctor() {}
63     };
64 }
65 
66 int main(int, char**)
67 {
68     test_constexpr<optional<int>>();
69     test_constexpr<optional<int*>>();
70     test_constexpr<optional<ImplicitTypes::NoCtors>>();
71     test_constexpr<optional<NonTrivialTypes::NoCtors>>();
72     test_constexpr<optional<NonConstexprTypes::NoCtors>>();
73     test<optional<NonLiteralTypes::NoCtors>>();
74 
75   return 0;
76 }
77