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, c++11, c++14, c++17
10
11// <sstream>
12
13// template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
14// class basic_stringbuf
15
16// void swap(basic_stringbuf& rhs)
17// noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||
18// allocator_traits<allocator_type>::is_always_equal::value);
19
20#include <sstream>
21#include <cassert>
22
23#include "test_macros.h"
24
25template <class T>
26struct test_alloc {
27 using value_type = T;
28
29 [[nodiscard]] constexpr T* allocate(std::size_t) { return nullptr; }
30 void deallocate(void*, std::size_t) {}
31};
32
33template <class T>
34struct test_alloc_propagate_on_container_swap : test_alloc<T> {
35 using propagate_on_container_swap = std::true_type;
36};
37
38template <class T>
39struct test_alloc_is_always_equal : test_alloc<T> {
40 using is_always_equal = std::true_type;
41};
42
43template <class T>
44struct test_alloc_propagate_on_container_swap_is_always_equal : test_alloc<T> {
45 using propagate_on_container_swap = std::true_type;
46 using is_always_equal = std::true_type;
47};
48
49template <class T>
50struct test_alloc_not_empty : test_alloc<T> {
51 bool dummy;
52};
53
54template <class T>
55struct test_alloc_propagate_on_container_swap_not_empty : test_alloc<T> {
56 using propagate_on_container_swap = std::true_type;
57 bool dummy;
58};
59
60template <class CharT>
61static void test() {
62 {
63 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc<CharT>> buf1;
64 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc<CharT>> buf;
65 static_assert(noexcept(buf.swap(buf1)));
66 }
67 {
68 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_propagate_on_container_swap<CharT>> buf1;
69 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_propagate_on_container_swap<CharT>> buf;
70 static_assert(noexcept(buf.swap(buf1)));
71 }
72 {
73 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_is_always_equal<CharT>> buf1;
74 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_is_always_equal<CharT>> buf;
75 static_assert(noexcept(buf.swap(buf1)));
76 }
77 {
78 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_propagate_on_container_swap_is_always_equal<CharT>>
79 buf1;
80 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_propagate_on_container_swap_is_always_equal<CharT>>
81 buf;
82 static_assert(noexcept(buf.swap(buf1)));
83 }
84 {
85 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_not_empty<CharT>> buf1;
86 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_not_empty<CharT>> buf;
87 LIBCPP_STATIC_ASSERT(!noexcept(buf.swap(buf1)));
88 }
89 {
90 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_propagate_on_container_swap_not_empty<CharT>> buf1;
91 std::basic_stringbuf<CharT, std::char_traits<CharT>, test_alloc_propagate_on_container_swap_not_empty<CharT>> buf;
92 static_assert(noexcept(buf.swap(buf1)));
93 }
94}
95
96int main(int, char**) {
97 test<char>();
98#ifndef TEST_HAS_NO_WIDE_CHARACTERS
99 test<wchar_t>();
100#endif
101 return 0;
102}
103

source code of libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.assign/member_swap_noexcept.pass.cpp