1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // UNSUPPORTED: c++98, c++03, c++11, c++14
11 
12 // <optional>
13 
14 // template <class U>
15 //   constexpr EXPLICIT optional(U&& u);
16 
17 #include <optional>
18 #include <type_traits>
19 #include <cassert>
20 
21 #include "test_macros.h"
22 #include "archetypes.hpp"
23 #include "test_convertible.hpp"
24 
25 
26 using std::optional;
27 
28 struct ImplicitThrow
29 {
30     constexpr ImplicitThrow(int x) { if (x != -1) TEST_THROW(6);}
31 };
32 
33 struct ExplicitThrow
34 {
35     constexpr explicit ExplicitThrow(int x) { if (x != -1) TEST_THROW(6);}
36 };
37 
38 struct ImplicitAny {
39   template <class U>
40   constexpr ImplicitAny(U&&) {}
41 };
42 
43 
44 template <class To, class From>
45 constexpr bool implicit_conversion(optional<To>&& opt, const From& v)
46 {
47     using O = optional<To>;
48     static_assert(test_convertible<O, From>(), "");
49     static_assert(!test_convertible<O, void*>(), "");
50     static_assert(!test_convertible<O, From, int>(), "");
51     return opt && *opt == static_cast<To>(v);
52 }
53 
54 template <class To, class Input, class Expect>
55 constexpr bool explicit_conversion(Input&& in, const Expect& v)
56 {
57     using O = optional<To>;
58     static_assert(std::is_constructible<O, Input>::value, "");
59     static_assert(!std::is_convertible<Input, O>::value, "");
60     static_assert(!std::is_constructible<O, void*>::value, "");
61     static_assert(!std::is_constructible<O, Input, int>::value, "");
62     optional<To> opt(std::forward<Input>(in));
63     return opt && *opt == static_cast<To>(v);
64 }
65 
66 void test_implicit()
67 {
68     {
69         static_assert(implicit_conversion<long long>(42, 42), "");
70     }
71     {
72         static_assert(implicit_conversion<long double>(3.14, 3.14), "");
73     }
74     {
75         int x = 42;
76         optional<void* const> o(&x);
77         assert(*o == &x);
78     }
79     {
80         using T = TrivialTestTypes::TestType;
81         static_assert(implicit_conversion<T>(42, 42), "");
82     }
83     {
84         using T = TestTypes::TestType;
85         assert(implicit_conversion<T>(3, T(3)));
86     }
87   {
88     using O = optional<ImplicitAny>;
89     static_assert(!test_convertible<O, std::in_place_t>(), "");
90     static_assert(!test_convertible<O, std::in_place_t&>(), "");
91     static_assert(!test_convertible<O, const std::in_place_t&>(), "");
92     static_assert(!test_convertible<O, std::in_place_t&&>(), "");
93     static_assert(!test_convertible<O, const std::in_place_t&&>(), "");
94 
95   }
96 #ifndef TEST_HAS_NO_EXCEPTIONS
97     {
98         try {
99             using T = ImplicitThrow;
100             optional<T> t = 42;
101             assert(false);
102             ((void)t);
103         } catch (int) {
104         }
105     }
106 #endif
107 }
108 
109 void test_explicit() {
110     {
111         using T = ExplicitTrivialTestTypes::TestType;
112         static_assert(explicit_conversion<T>(42, 42), "");
113     }
114     {
115         using T = ExplicitConstexprTestTypes::TestType;
116         static_assert(explicit_conversion<T>(42, 42), "");
117         static_assert(!std::is_convertible<int, T>::value, "");
118     }
119     {
120         using T = ExplicitTestTypes::TestType;
121         T::reset();
122         {
123             assert(explicit_conversion<T>(42, 42));
124             assert(T::alive == 0);
125         }
126         T::reset();
127         {
128             optional<T> t(42);
129             assert(T::alive == 1);
130             assert(T::value_constructed == 1);
131             assert(T::move_constructed == 0);
132             assert(T::copy_constructed == 0);
133             assert(t.value().value == 42);
134         }
135         assert(T::alive == 0);
136     }
137 #ifndef TEST_HAS_NO_EXCEPTIONS
138     {
139         try {
140             using T = ExplicitThrow;
141             optional<T> t(42);
142             assert(false);
143         } catch (int) {
144         }
145     }
146 #endif
147 }
148 
149 int main() {
150     test_implicit();
151     test_explicit();
152 }
153