chromium/third_party/pdfium/core/fxcrt/shared_copy_on_write.h

// Copyright 2016 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#ifndef CORE_FXCRT_SHARED_COPY_ON_WRITE_H_
#define CORE_FXCRT_SHARED_COPY_ON_WRITE_H_

#include "core/fxcrt/fx_system.h"
#include "core/fxcrt/retain_ptr.h"

namespace fxcrt {

// A shared pointer to an object with Copy on Write semantics that makes it
// appear as if all instances were independent. |ObjClass| must implement the
// requirements of |Retainable| from retain_ptr.h, and must also provide a
// Clone() method. Often this will just call MakeRetain<>(*this) but will need
// to be virtual if |ObjClass| is subclassed.
template <class ObjClass>
class SharedCopyOnWrite { … };

}  // namespace fxcrt

SharedCopyOnWrite;

#endif  // CORE_FXCRT_SHARED_COPY_ON_WRITE_H_