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 12 // <shared_mutex> 13 14 // template <class Mutex> class shared_lock; 15 16 // explicit operator bool() const noexcept; 17 18 #include <shared_mutex> 19 #include <cassert> 20 21 #if _LIBCPP_STD_VER > 11 22 23 std::shared_timed_mutex m; 24 25 #endif // _LIBCPP_STD_VER > 11 26 main()27int main() 28 { 29 #if _LIBCPP_STD_VER > 11 30 std::shared_lock<std::shared_timed_mutex> lk0; 31 assert(static_cast<bool>(lk0) == false); 32 std::shared_lock<std::shared_timed_mutex> lk1(m); 33 assert(static_cast<bool>(lk1) == true); 34 lk1.unlock(); 35 assert(static_cast<bool>(lk1) == false); 36 static_assert(noexcept(static_cast<bool>(lk0)), "explicit operator bool() must be noexcept"); 37 #endif // _LIBCPP_STD_VER > 11 38 } 39