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 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
10 
11 // <memory>
12 
13 // template <class T> struct owner_less;
14 //
15 // template <class T>
16 // struct owner_less<shared_ptr<T> >
17 //     : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
18 // {
19 //     typedef bool result_type;
20 //     bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
21 //     bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
22 //     bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
23 // };
24 //
25 // template <class T>
26 // struct owner_less<weak_ptr<T> >
27 //     : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
28 // {
29 //     typedef bool result_type;
30 //     bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
31 //     bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
32 //     bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
33 // };
34 //
35 // Added in C++17
36 // template<> struct owner_less<void>
37 // {
38 //     template<class T, class U>
39 //         bool operator()(shared_ptr<T> const&, shared_ptr<U> const&) const noexcept;
40 //     template<class T, class U>
41 //         bool operator()(shared_ptr<T> const&, weak_ptr<U> const&) const noexcept;
42 //     template<class T, class U>
43 //         bool operator()(weak_ptr<T> const&, shared_ptr<U> const&) const noexcept;
44 //     template<class T, class U>
45 //         bool operator()(weak_ptr<T> const&, weak_ptr<U> const&) const noexcept;
46 //
47 //     typedef unspecified is_transparent;
48 // };
49 
50 #include <memory>
51 #include <cassert>
52 #include <set>
53 #include "test_macros.h"
54 
55 struct X {};
56 
main(int,char **)57 int main(int, char**)
58 {
59     const std::shared_ptr<int> p1(new int);
60     const std::shared_ptr<int> p2 = p1;
61     const std::shared_ptr<int> p3(new int);
62     const std::weak_ptr<int> w1(p1);
63     const std::weak_ptr<int> w2(p2);
64     const std::weak_ptr<int> w3(p3);
65 
66     {
67     typedef std::owner_less<std::shared_ptr<int> > CS;
68     CS cs;
69 
70 #if TEST_STD_VER <= 17
71     static_assert((std::is_same<std::shared_ptr<int>, CS::first_argument_type>::value), "" );
72     static_assert((std::is_same<std::shared_ptr<int>, CS::second_argument_type>::value), "" );
73     static_assert((std::is_same<bool, CS::result_type>::value), "" );
74 #endif
75 
76     assert(!cs(p1, p2));
77     assert(!cs(p2, p1));
78     assert(cs(p1 ,p3) || cs(p3, p1));
79     assert(cs(p3, p1) == cs(p3, p2));
80     ASSERT_NOEXCEPT(cs(p1, p1));
81 
82     assert(!cs(p1, w2));
83     assert(!cs(p2, w1));
84     assert(cs(p1, w3) || cs(p3, w1));
85     assert(cs(p3, w1) == cs(p3, w2));
86     ASSERT_NOEXCEPT(cs(p1, w1));
87     ASSERT_NOEXCEPT(cs(w1, p1));
88     }
89     {
90     typedef std::owner_less<std::weak_ptr<int> > CS;
91     CS cs;
92 
93 #if TEST_STD_VER <= 17
94     static_assert((std::is_same<std::weak_ptr<int>, CS::first_argument_type>::value), "" );
95     static_assert((std::is_same<std::weak_ptr<int>, CS::second_argument_type>::value), "" );
96     static_assert((std::is_same<bool, CS::result_type>::value), "" );
97 #endif
98 
99     assert(!cs(w1, w2));
100     assert(!cs(w2, w1));
101     assert(cs(w1, w3) || cs(w3, w1));
102     assert(cs(w3, w1) == cs(w3, w2));
103     ASSERT_NOEXCEPT(cs(w1, w1));
104 
105     assert(!cs(w1, p2));
106     assert(!cs(w2, p1));
107     assert(cs(w1, p3) || cs(w3, p1));
108     assert(cs(w3, p1) == cs(w3, p2));
109     ASSERT_NOEXCEPT(cs(w1, p1));
110     ASSERT_NOEXCEPT(cs(p1, w1));
111     }
112 #if TEST_STD_VER > 14
113     {
114     std::shared_ptr<int> sp1;
115     std::shared_ptr<void> sp2;
116     std::shared_ptr<long> sp3;
117     std::weak_ptr<int> wp1;
118 
119     std::owner_less<> cmp;
120     assert(!cmp(sp1, sp2));
121     assert(!cmp(sp1, wp1));
122     assert(!cmp(sp1, sp3));
123     assert(!cmp(wp1, sp1));
124     assert(!cmp(wp1, wp1));
125     ASSERT_NOEXCEPT(cmp(sp1, sp1));
126     ASSERT_NOEXCEPT(cmp(sp1, wp1));
127     ASSERT_NOEXCEPT(cmp(wp1, sp1));
128     ASSERT_NOEXCEPT(cmp(wp1, wp1));
129     }
130     {
131     // test heterogeneous lookups
132     std::set<std::shared_ptr<X>, std::owner_less<>> s;
133     std::shared_ptr<void> vp;
134     assert(s.find(vp) == s.end());
135     }
136 #endif
137 
138   return 0;
139 }
140