1/* 2 * Copyright (C) 2000 Lars Knoll (knoll@kde.org) 3 * (C) 2000 Antti Koivisto (koivisto@kde.org) 4 * (C) 2000 Dirk Mueller (mueller@kde.org) 5 * Copyright (C) 2003, 2005, 2008 Apple Inc. All rights reserved. 6 * 7 * This library is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Library General Public 9 * License as published by the Free Software Foundation; either 10 * version 2 of the License, or (at your option) any later version. 11 * 12 * This library is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Library General Public License for more details. 16 * 17 * You should have received a copy of the GNU Library General Public License 18 * along with this library; see the file COPYING.LIB. If not, write to 19 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 20 * Boston, MA 02110-1301, USA. 21 * 22 */ 23 24#ifndef DataRef_h 25#define DataRef_h 26 27#include <wtf/PassRef.h> 28#include <wtf/Ref.h> 29 30namespace WebCore { 31 32template <typename T> class DataRef { 33public: 34 DataRef(PassRef<T> data) : m_data(WTF::move(data)) { } 35 DataRef(const DataRef& other) : m_data(const_cast<T&>(other.m_data.get())) { } 36 DataRef& operator=(const DataRef& other) { m_data = const_cast<T&>(other.m_data.get()); return *this; } 37 38 const T* get() const { return &m_data.get(); } 39 40 const T& operator*() const { return *get(); } 41 const T* operator->() const { return get(); } 42 43 T* access() 44 { 45 if (!m_data->hasOneRef()) 46 m_data = m_data->copy(); 47 return &m_data.get(); 48 } 49 50 bool operator==(const DataRef<T>& o) const 51 { 52 return &m_data.get() == &o.m_data.get() || m_data.get() == o.m_data.get(); 53 } 54 55 bool operator!=(const DataRef<T>& o) const 56 { 57 return &m_data.get() != &o.m_data.get() && m_data.get() != o.m_data.get(); 58 } 59 60private: 61 Ref<T> m_data; 62}; 63 64} // namespace WebCore 65 66#endif // DataRef_h 67