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++98, c++03, c++11, c++14
10 // <optional>
11 
12 // template <class T> struct hash<optional<T>>;
13 
14 #include <optional>
15 #include <string>
16 #include <memory>
17 #include <cassert>
18 
19 #include "poisoned_hash_helper.hpp"
20 
21 struct A {};
22 struct B {};
23 
24 namespace std {
25 
26 template <>
27 struct hash<B> {
28   size_t operator()(B const&) TEST_NOEXCEPT_FALSE { return 0; }
29 };
30 
31 }
32 
33 int main(int, char**)
34 {
35     using std::optional;
36     const std::size_t nullopt_hash =
37         std::hash<optional<double>>{}(optional<double>{});
38 
39 
40     {
41         optional<B> opt;
42         ASSERT_NOT_NOEXCEPT(std::hash<optional<B>>()(opt));
43         ASSERT_NOT_NOEXCEPT(std::hash<optional<const B>>()(opt));
44     }
45 
46     {
47         typedef int T;
48         optional<T> opt;
49         assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
50         opt = 2;
51         assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
52     }
53     {
54         typedef std::string T;
55         optional<T> opt;
56         assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
57         opt = std::string("123");
58         assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
59     }
60     {
61         typedef std::unique_ptr<int> T;
62         optional<T> opt;
63         assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
64         opt = std::unique_ptr<int>(new int(3));
65         assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
66     }
67     {
68       test_hash_enabled_for_type<std::optional<int> >();
69       test_hash_enabled_for_type<std::optional<int*> >();
70       test_hash_enabled_for_type<std::optional<const int> >();
71       test_hash_enabled_for_type<std::optional<int* const> >();
72 
73       test_hash_disabled_for_type<std::optional<A>>();
74       test_hash_disabled_for_type<std::optional<const A>>();
75 
76       test_hash_enabled_for_type<std::optional<B>>();
77       test_hash_enabled_for_type<std::optional<const B>>();
78     }
79 
80   return 0;
81 }
82