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