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