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 Alloc>
13 // struct allocator_traits
14 // {
15 //     static allocator_type
16 //         select_on_container_copy_construction(const allocator_type& a);
17 //     ...
18 // };
19 
20 #include <memory>
21 #include <new>
22 #include <type_traits>
23 #include <cassert>
24 
25 template <class T>
26 struct A
27 {
28     typedef T value_type;
29     int id;
30     explicit A(int i = 0) : id(i) {}
31 
32 };
33 
34 template <class T>
35 struct B
36 {
37     typedef T value_type;
38 
39     int id;
40     explicit B(int i = 0) : id(i) {}
41 
42     B select_on_container_copy_construction() const
43     {
44         return B(100);
45     }
46 };
47 
48 int main()
49 {
50     {
51         A<int> a;
52         assert(std::allocator_traits<A<int> >::select_on_container_copy_construction(a).id == 0);
53     }
54     {
55         const A<int> a(0);
56         assert(std::allocator_traits<A<int> >::select_on_container_copy_construction(a).id == 0);
57     }
58 #ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
59     {
60         B<int> b;
61         assert(std::allocator_traits<B<int> >::select_on_container_copy_construction(b).id == 100);
62     }
63     {
64         const B<int> b(0);
65         assert(std::allocator_traits<B<int> >::select_on_container_copy_construction(b).id == 100);
66     }
67 #endif  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
68 }
69