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// <list>
12
13// void swap(list& 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>::is_always_equal::value);
19
20// This tests a conforming extension
21
22#include <list>
23#include <utility>
24#include <cassert>
25
26#include "test_macros.h"
27#include "MoveOnly.h"
28#include "test_allocator.h"
29
30template <class T>
31struct some_alloc {
32 typedef T value_type;
33
34 some_alloc() {}
35 some_alloc(const some_alloc&);
36 void allocate(std::size_t);
37 void deallocate(void*, unsigned) {}
38
39 typedef std::true_type propagate_on_container_swap;
40};
41
42template <class T>
43struct some_alloc2 {
44 typedef T value_type;
45
46 some_alloc2() {}
47 some_alloc2(const some_alloc2&);
48 void allocate(std::size_t);
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
55int main(int, char**) {
56 {
57 typedef std::list<MoveOnly> C;
58 static_assert(noexcept(swap(a&: std::declval<C&>(), b&: std::declval<C&>())), "");
59 }
60#if defined(_LIBCPP_VERSION)
61 {
62 typedef std::list<MoveOnly, test_allocator<MoveOnly>> C;
63 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
64 }
65 {
66 typedef std::list<MoveOnly, other_allocator<MoveOnly>> C;
67 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
68 }
69#endif // _LIBCPP_VERSION
70 {
71 typedef std::list<MoveOnly, some_alloc<MoveOnly>> C;
72#if TEST_STD_VER >= 14
73 // In C++14, if POCS is set, swapping the allocator is required not to throw
74 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
75#else
76 static_assert(!noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
77#endif
78 }
79#if TEST_STD_VER >= 14
80 {
81 typedef std::list<MoveOnly, some_alloc2<MoveOnly>> C;
82 // if the allocators are always equal, then the swap can be noexcept
83 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
84 }
85#endif
86
87 return 0;
88}
89

source code of libcxx/test/std/containers/sequences/list/list.special/swap_noexcept.pass.cpp