libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/member_swap.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: c++03, c++11
  11
  12 // <shared_mutex>
  13
  14 // template <class Mutex> class shared_lock;
  15
  16 // void swap(shared_lock& u) noexcept;
  17
  18 #include <shared_mutex>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22
  23 struct mutex
  24 {
  25     void lock_shared() {}
  26     void unlock_shared() {}
  27 };
  28
  29 mutex m;
  30
  31 int main(int, char**)
  32 {
  33     std::shared_lock<mutex> lk1(m);
  34     std::shared_lock<mutex> lk2;
  35     lk1.swap(lk2);
  36     assert(lk1.mutex() == nullptr);
  37     assert(lk1.owns_lock() == false);
  38     assert(lk2.mutex() == &m);
  39     assert(lk2.owns_lock() == true);
  40     static_assert(noexcept(lk1.swap(lk2)), "member swap must be noexcept");
  41
  42   return 0;
  43 }