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() noexcept;
13 
14 #include <optional>
15 #include <type_traits>
16 #include <cassert>
17 
18 #include "test_macros.h"
19 #include "archetypes.h"
20 
21 using std::optional;
22 
23 template <class Opt>
24 void
25 test_constexpr()
26 {
27     static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
28     static_assert(std::is_trivially_destructible<Opt>::value, "");
29     static_assert(std::is_trivially_destructible<typename Opt::value_type>::value, "");
30 
31     constexpr Opt opt;
32     static_assert(static_cast<bool>(opt) == false, "");
33 
34     struct test_constexpr_ctor
35         : public Opt
36     {
37         constexpr test_constexpr_ctor() {}
38     };
39 }
40 
41 template <class Opt>
42 void
43 test()
44 {
45     static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
46     static_assert(!std::is_trivially_destructible<Opt>::value, "");
47     static_assert(!std::is_trivially_destructible<typename Opt::value_type>::value, "");
48     {
49         Opt opt;
50         assert(static_cast<bool>(opt) == false);
51     }
52     {
53         const Opt opt;
54         assert(static_cast<bool>(opt) == false);
55     }
56 
57     struct test_constexpr_ctor
58         : public Opt
59     {
60         constexpr test_constexpr_ctor() {}
61     };
62 }
63 
64 int main(int, char**)
65 {
66     test_constexpr<optional<int>>();
67     test_constexpr<optional<int*>>();
68     test_constexpr<optional<ImplicitTypes::NoCtors>>();
69     test_constexpr<optional<NonTrivialTypes::NoCtors>>();
70     test_constexpr<optional<NonConstexprTypes::NoCtors>>();
71     test<optional<NonLiteralTypes::NoCtors>>();
72     // EXTENSIONS
73 #if defined(_LIBCPP_VERSION) && 0 // FIXME these extensions are currently disabled.
74     test_constexpr<optional<int&>>();
75     test_constexpr<optional<const int&>>();
76     test_constexpr<optional<int&>>();
77     test_constexpr<optional<NonLiteralTypes::NoCtors&>>();
78     test_constexpr<optional<NonLiteralTypes::NoCtors&&>>();
79 #endif
80 
81   return 0;
82 }
83