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 "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 deallocate(void*, unsigned) {}
37
38 typedef std::true_type propagate_on_container_swap;
39};
40
41template <class T>
42struct some_alloc2 {
43 typedef T value_type;
44
45 some_alloc2() {}
46 some_alloc2(const some_alloc2&);
47 void deallocate(void*, unsigned) {}
48
49 typedef std::false_type propagate_on_container_swap;
50 typedef std::true_type is_always_equal;
51};
52
53int main(int, char**) {
54#if defined(_LIBCPP_VERSION)
55 {
56 typedef std::vector<bool> C;
57 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
58 }
59 {
60 typedef std::vector<bool, test_allocator<bool>> C;
61 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
62 }
63 {
64 typedef std::vector<bool, other_allocator<bool>> C;
65 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
66 }
67#endif // _LIBCPP_VERSION
68 {
69#if TEST_STD_VER >= 14
70# if defined(_LIBCPP_VERSION)
71 // In C++14, if POCS is set, swapping the allocator is required not to throw
72 typedef std::vector<bool, some_alloc<bool>> C;
73 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
74# endif // _LIBCPP_VERSION
75#else
76 typedef std::vector<bool, some_alloc<bool>> C;
77 static_assert(!noexcept(swap(x&: std::declval<C&>(), y&: std::declval<C&>())), "");
78#endif
79 }
80#if TEST_STD_VER >= 14
81# if defined(_LIBCPP_VERSION)
82 {
83 typedef std::vector<bool, some_alloc2<bool>> C;
84 // if the allocators are always equal, then the swap can be noexcept
85 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
86 }
87# endif // _LIBCPP_VERSION
88#endif
89
90 return 0;
91}
92

source code of libcxx/test/std/containers/sequences/vector.bool/swap_noexcept.pass.cpp