31 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// <mutex>10 11// template <class Mutex> class lock_guard;12 13// explicit lock_guard(mutex_type& m);14 15#include <cassert>16#include <mutex>17#include <type_traits>18 19#include "types.h"20 21int main(int, char**) {22 MyMutex m;23 assert(!m.locked);24 std::lock_guard<MyMutex> lg(m);25 assert(m.locked);26 27 static_assert(!std::is_convertible<MyMutex, std::lock_guard<MyMutex> >::value, "constructor must be explicit");28 29 return 0;30}31