libcxx/test/std/thread/thread.jthread/swap.free.pass.cpp

   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
  23 template <class T>
  24 concept IsFreeSwapNoexcept = requires(T& a, T& b) {
  25   { swap(a, b) } noexcept;
  26 };
  27
  28 static_assert(IsFreeSwapNoexcept<std::jthread>);
  29
  30 int 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(t1, 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(t1, 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(t1, 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(t1, t2);
  70
  71     assert(t1.get_id() == std::jthread::id());
  72     assert(t2.get_id() == std::jthread::id());
  73   }
  74
  75   return 0;
  76 }