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 // 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.h"
20 
21 #include "test_macros.h"
22 
23 struct A {};
24 struct B {};
25 
26 namespace std {
27 
28 template <>
29 struct hash<B> {
operator ()std::hash30   size_t operator()(B const&) TEST_NOEXCEPT_FALSE { return 0; }
31 };
32 
33 }
34 
main(int,char **)35 int main(int, char**)
36 {
37     using std::optional;
38     const std::size_t nullopt_hash =
39         std::hash<optional<double>>{}(optional<double>{});
40 
41 
42     {
43         optional<B> opt;
44         ASSERT_NOT_NOEXCEPT(std::hash<optional<B>>()(opt));
45         ASSERT_NOT_NOEXCEPT(std::hash<optional<const B>>()(opt));
46     }
47 
48     {
49         typedef int T;
50         optional<T> opt;
51         assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
52         opt = 2;
53         assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
54     }
55     {
56         typedef std::string T;
57         optional<T> opt;
58         assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
59         opt = std::string("123");
60         assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
61     }
62     {
63         typedef std::unique_ptr<int> T;
64         optional<T> opt;
65         assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
66         opt = std::unique_ptr<int>(new int(3));
67         assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
68     }
69     {
70       test_hash_enabled_for_type<std::optional<int> >();
71       test_hash_enabled_for_type<std::optional<int*> >();
72       test_hash_enabled_for_type<std::optional<const int> >();
73       test_hash_enabled_for_type<std::optional<int* const> >();
74 
75       test_hash_disabled_for_type<std::optional<A>>();
76       test_hash_disabled_for_type<std::optional<const A>>();
77 
78       test_hash_enabled_for_type<std::optional<B>>();
79       test_hash_enabled_for_type<std::optional<const B>>();
80     }
81 
82   return 0;
83 }
84