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 } 34