chromium/base/memory/weak_auto_reset.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_MEMORY_WEAK_AUTO_RESET_H_
#define BASE_MEMORY_WEAK_AUTO_RESET_H_

#include "base/memory/weak_ptr.h"

namespace base {

// Sets a field of an object to a specified value, then returns it to its
// original value when the WeakAutoReset instance goes out of scope. Because a
// weak pointer is used, if the target object is destroyed, no attempt is made
// to restore the original value and no UAF occurs.
//
// Note that as of C++17 we can use CTAD to infer template parameters from
// constructor args; it is valid to write:
//   WeakAutoReset war(myobj->GetWeakPtr(), &MyClass::member_, new_value);
// without specifying explicit types in the classname.
template <class T, class U>
class WeakAutoReset { … };

}  // namespace base

#endif  // BASE_MEMORY_WEAK_AUTO_RESET_H_