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 // UNSUPPORTED: c++98, c++03
11 
12 // <deque>
13 
14 // void swap(deque& c)
15 //     noexcept(!allocator_type::propagate_on_container_swap::value ||
16 //              __is_nothrow_swappable<allocator_type>::value);
17 //
18 //  In C++17, the standard says that swap shall have:
19 //     noexcept(allocator_traits<Allocator>::is_always_equal::value);
20 
21 // This tests a conforming extension
22 
23 #include <deque>
24 #include <cassert>
25 
26 #include "test_macros.h"
27 #include "MoveOnly.h"
28 #include "test_allocator.h"
29 
30 template <class T>
31 struct some_alloc
32 {
33     typedef T value_type;
34 
35     some_alloc() {}
36     some_alloc(const some_alloc&);
37     void deallocate(void*, unsigned) {}
38 
39     typedef std::true_type propagate_on_container_swap;
40 };
41 
42 template <class T>
43 struct some_alloc2
44 {
45     typedef T value_type;
46 
47     some_alloc2() {}
48     some_alloc2(const some_alloc2&);
49     void deallocate(void*, unsigned) {}
50 
51     typedef std::false_type propagate_on_container_swap;
52     typedef std::true_type is_always_equal;
53 };
54 
55 int main()
56 {
57     {
58         typedef std::deque<MoveOnly> C;
59         C c1, c2;
60         static_assert(noexcept(swap(c1, c2)), "");
61     }
62     {
63         typedef std::deque<MoveOnly, test_allocator<MoveOnly>> C;
64         C c1, c2;
65         static_assert(noexcept(swap(c1, c2)), "");
66     }
67     {
68         typedef std::deque<MoveOnly, other_allocator<MoveOnly>> C;
69         C c1, c2;
70         static_assert(noexcept(swap(c1, c2)), "");
71     }
72     {
73         typedef std::deque<MoveOnly, some_alloc<MoveOnly>> C;
74         C c1, c2;
75 #if TEST_STD_VER >= 14
76     //  In c++14, if POCS is set, swapping the allocator is required not to throw
77         static_assert( noexcept(swap(c1, c2)), "");
78 #else
79         static_assert(!noexcept(swap(c1, c2)), "");
80 #endif
81     }
82 #if TEST_STD_VER >= 14
83     {
84         typedef std::deque<MoveOnly, some_alloc2<MoveOnly>> C;
85         C c1, c2;
86     //  if the allocators are always equal, then the swap can be noexcept
87         static_assert( noexcept(swap(c1, c2)), "");
88     }
89 #endif
90 
91 }
92