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 // <shared_mutex> 11 12 // template <class Mutex> class shared_lock; 13 14 // void swap(shared_lock& u) noexcept; 15 16 #include <shared_mutex> 17 #include <cassert> 18 19 #if _LIBCPP_STD_VER > 11 20 21 struct mutex 22 { 23 void lock_shared() {} 24 void unlock_shared() {} 25 }; 26 27 mutex m; 28 29 #endif // _LIBCPP_STD_VER > 11 30 31 int main() 32 { 33 #if _LIBCPP_STD_VER > 11 34 std::shared_lock<mutex> lk1(m); 35 std::shared_lock<mutex> lk2; 36 lk1.swap(lk2); 37 assert(lk1.mutex() == nullptr); 38 assert(lk1.owns_lock() == false); 39 assert(lk2.mutex() == &m); 40 assert(lk2.owns_lock() == true); 41 static_assert(noexcept(lk1.swap(lk2)), "member swap must be noexcept"); 42 #endif // _LIBCPP_STD_VER > 11 43 } 44
