1 // { dg-do run { target c++11 } }
2
3 // Copyright (C) 2008-2021 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING3. If not see
18 // <http://www.gnu.org/licenses/>.
19
20 // 20.8.13.2 Template class shared_ptr [util.smartptr.shared]
21
22 #include <memory>
23 #include <testsuite_hooks.h>
24
25 struct A { };
26
27 namespace std
28 {
29 template<>
30 struct less<A*> : binary_function<A*,A*,bool>
31 {
32 static int count;
operator ()std::less33 bool operator()(A* l, A* r) { ++count; return l < r; }
34 };
35 int less<A*>::count = 0;
36 }
37
38 // 20.8.13.2.7 shared_ptr comparison [util.smartptr.shared.cmp]
39
40
41 int
test01()42 test01()
43 {
44 std::less<std::shared_ptr<A>> less;
45 // test empty shared_ptrs compare equivalent
46 std::shared_ptr<A> p1;
47 std::shared_ptr<A> p2;
48 VERIFY( !less(p1, p2) && !less(p2, p1) );
49 #ifndef __cpp_lib_three_way_comparison
50 // In C++20 std::less<std::shared_ptr<A>> uses the operator< synthesized
51 // from operator<=>, which uses std::compare_three_way not std::less<A*>.
52 VERIFY( std::less<A*>::count == 2 );
53 #endif
54 return 0;
55 }
56
57
58 // Construction from pointer
59 int
test02()60 test02()
61 {
62 std::less<std::shared_ptr<A>> less;
63
64 std::shared_ptr<A> empty;
65 std::shared_ptr<A> p1(new A);
66 std::shared_ptr<A> p2(new A);
67
68 VERIFY( less(p1, p2) || less(p2, p1) );
69 VERIFY( !(less(p1, p2) && less(p2, p1)) );
70
71 p1.reset();
72 VERIFY( !less(p1, empty) && !less(empty, p1) );
73
74 p2.reset();
75 VERIFY( !less(p1, p2) && !less(p2, p1) );
76
77 return 0;
78 }
79
80 // Aliasing
81 int
test03()82 test03()
83 {
84 std::less<std::shared_ptr<A>> less;
85
86 A a;
87 std::shared_ptr<A> p1(new A);
88 std::shared_ptr<A> p2(p1, &a);
89 VERIFY( less(p1, p2) || less(p2, p1) );
90
91 return 0;
92 }
93 int
main()94 main()
95 {
96 test01();
97 test02();
98 test03();
99 return 0;
100 }
101