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{
33 typedef T value_type;
34
35 some_alloc() {}
36 some_alloc(const some_alloc&);
37 void allocate(std::size_t);
38 void deallocate(void*, unsigned) {}
39
40 typedef std::true_type propagate_on_container_swap;
41};
42
43template <class T>
44struct some_alloc2
45{
46 typedef T value_type;
47
48 some_alloc2() {}
49 some_alloc2(const some_alloc2&);
50 void allocate(std::size_t);
51 void deallocate(void*, unsigned) {}
52
53 typedef std::false_type propagate_on_container_swap;
54 typedef std::true_type is_always_equal;
55};
56
57int main(int, char**)
58{
59 {
60 typedef std::list<MoveOnly> C;
61 static_assert(noexcept(swap(a&: std::declval<C&>(), b&: std::declval<C&>())), "");
62 }
63#if defined(_LIBCPP_VERSION)
64 {
65 typedef std::list<MoveOnly, test_allocator<MoveOnly>> C;
66 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
67 }
68 {
69 typedef std::list<MoveOnly, other_allocator<MoveOnly>> C;
70 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
71 }
72#endif // _LIBCPP_VERSION
73 {
74 typedef std::list<MoveOnly, some_alloc<MoveOnly>> C;
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(std::declval<C&>(), std::declval<C&>())), "");
78#else
79 static_assert(!noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
80#endif
81 }
82#if TEST_STD_VER >= 14
83 {
84 typedef std::list<MoveOnly, some_alloc2<MoveOnly>> C;
85 // if the allocators are always equal, then the swap can be noexcept
86 static_assert( noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
87 }
88#endif
89
90
91 return 0;
92}
93

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