test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/op_bool.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // UNSUPPORTED: libcpp-has-no-threads
  11 // UNSUPPORTED: c++98, c++03, c++11
  12
  13 // <shared_mutex>
  14
  15 // template <class Mutex> class shared_lock;
  16
  17 // explicit operator bool() const noexcept;
  18
  19 #include <shared_mutex>
  20 #include <cassert>
  21
  22 std::shared_timed_mutex m;
  23
  24 int main()
  25 {
  26     std::shared_lock<std::shared_timed_mutex> lk0;
  27     assert(static_cast<bool>(lk0) == false);
  28     std::shared_lock<std::shared_timed_mutex> lk1(m);
  29     assert(static_cast<bool>(lk1) == true);
  30     lk1.unlock();
  31     assert(static_cast<bool>(lk1) == false);
  32     static_assert(noexcept(static_cast<bool>(lk0)), "explicit operator bool() must be noexcept");
  33 }