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 // UNSUPPORTED: c++03
10 
11 // <vector>
12 
13 // void swap(vector& c)
14 //     noexcept(!allocator_type::propagate_on_container_swap::value ||
15 //              __is_nothrow_swappable<allocator_type>::value);
16 //
17 //  In C++17, the standard says that swap shall have:
18 //     noexcept(allocator_traits<Allocator>::propagate_on_container_swap::value ||
19 //              allocator_traits<Allocator>::is_always_equal::value);
20 
21 // This tests a conforming extension
22 
23 #include <vector>
24 #include <utility>
25 #include <cassert>
26 
27 #include "test_macros.h"
28 #include "MoveOnly.h"
29 #include "test_allocator.h"
30 
31 template <class T>
32 struct some_alloc
33 {
34     typedef T value_type;
35 
some_allocsome_alloc36     some_alloc() {}
37     some_alloc(const some_alloc&);
38     void allocate(std::size_t);
deallocatesome_alloc39     void deallocate(void*, unsigned) {}
40 
41     typedef std::true_type propagate_on_container_swap;
42 };
43 
44 template <class T>
45 struct some_alloc2
46 {
47     typedef T value_type;
48 
some_alloc2some_alloc249     some_alloc2() {}
50     some_alloc2(const some_alloc2&);
51     void allocate(std::size_t);
deallocatesome_alloc252     void deallocate(void*, unsigned) {}
53 
54     typedef std::false_type propagate_on_container_swap;
55     typedef std::true_type is_always_equal;
56 };
57 
test()58 void test()
59 {
60     {
61         typedef std::vector<MoveOnly> C;
62         static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
63     }
64 #if defined(_LIBCPP_VERSION)
65     {
66         typedef std::vector<MoveOnly, test_allocator<MoveOnly>> C;
67         static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
68     }
69 #endif
70     {
71         typedef std::vector<MoveOnly, other_allocator<MoveOnly>> C;
72         static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
73     }
74     {
75         typedef std::vector<MoveOnly, some_alloc<MoveOnly>> C;
76 #if TEST_STD_VER >= 14
77         //  In C++14, if POCS is set, swapping the allocator is required not to throw
78         static_assert( noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
79 #else
80         static_assert(!noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
81 #endif
82     }
83 #if TEST_STD_VER >= 14
84     {
85         typedef std::vector<MoveOnly, some_alloc2<MoveOnly>> C;
86         // If the allocators are always equal, then the swap can be noexcept
87         static_assert( noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
88     }
89 #endif
90 }
91