libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/mutex.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 // mutex_type *mutex() const noexcept;
  17
  18 #include <shared_mutex>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22
  23 std::shared_timed_mutex m;
  24
  25 int main(int, char**)
  26 {
  27     std::shared_lock<std::shared_timed_mutex> lk0;
  28     assert(lk0.mutex() == nullptr);
  29     std::shared_lock<std::shared_timed_mutex> lk1(m);
  30     assert(lk1.mutex() == &m);
  31     lk1.unlock();
  32     assert(lk1.mutex() == &m);
  33     static_assert(noexcept(lk0.mutex()), "mutex() must be noexcept");
  34
  35   return 0;
  36 }