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 21struct mutex 22{ 23 void lock_shared() {} 24 void unlock_shared() {} 25}; 26 27mutex m; 28 29#endif // _LIBCPP_STD_VER > 11 30 31int 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