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: no-threads
10// UNSUPPORTED: libcpp-has-no-experimental-stop_token
11// UNSUPPORTED: c++03, c++11, c++14, c++17
12// XFAIL: availability-synchronization_library-missing
13
14// friend void swap(jthread& x, jthread& y) noexcept;
15
16#include <cassert>
17#include <thread>
18#include <type_traits>
19
20#include "make_test_thread.h"
21#include "test_macros.h"
22
23template <class T>
24concept IsFreeSwapNoexcept = requires(T& a, T& b) {
25 { swap(a, b) } noexcept;
26};
27
28static_assert(IsFreeSwapNoexcept<std::jthread>);
29
30int main(int, char**) {
31 // x is default constructed
32 {
33 std::jthread t1;
34 std::jthread t2 = support::make_test_jthread([] {});
35 const auto originalId2 = t2.get_id();
36 swap(x&: t1, y&: t2);
37
38 assert(t1.get_id() == originalId2);
39 assert(t2.get_id() == std::jthread::id());
40 }
41
42 // y is default constructed
43 {
44 std::jthread t1 = support::make_test_jthread([] {});
45 std::jthread t2{};
46 const auto originalId1 = t1.get_id();
47 swap(x&: t1, y&: t2);
48
49 assert(t1.get_id() == std::jthread::id());
50 assert(t2.get_id() == originalId1);
51 }
52
53 // both not default constructed
54 {
55 std::jthread t1 = support::make_test_jthread([] {});
56 std::jthread t2 = support::make_test_jthread([] {});
57 const auto originalId1 = t1.get_id();
58 const auto originalId2 = t2.get_id();
59 swap(x&: t1, y&: t2);
60
61 assert(t1.get_id() == originalId2);
62 assert(t2.get_id() == originalId1);
63 }
64
65 // both default constructed
66 {
67 std::jthread t1;
68 std::jthread t2;
69 swap(x&: t1, y&: t2);
70
71 assert(t1.get_id() == std::jthread::id());
72 assert(t2.get_id() == std::jthread::id());
73 }
74
75 return 0;
76}
77

source code of libcxx/test/std/thread/thread.jthread/swap.free.pass.cpp