// -*- mode: c++; c-basic-offset: 4 -*- /* * Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public License * along with this library; see the file COPYING.LIB. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA 02110-1301, USA. * */ #ifndef WTF_RefPtr_h #define WTF_RefPtr_h #include <algorithm> #include "AlwaysInline.h" namespace WTF { enum PlacementNewAdoptType { PlacementNewAdopt }; template <typename T> class PassRefPtr; enum HashTableDeletedValueType { HashTableDeletedValue }; template <typename T> class RefPtr { public: RefPtr() : m_ptr(0) { } RefPtr(T* ptr) : m_ptr(ptr) { if (ptr) ptr->ref(); } RefPtr(const RefPtr& o) : m_ptr(o.m_ptr) { if (T* ptr = m_ptr) ptr->ref(); } // see comment in PassRefPtr.h for why this takes const reference template <typename U> RefPtr(const PassRefPtr<U>&); // Special constructor for cases where we overwrite an object in place. RefPtr(PlacementNewAdoptType) { } // Hash table deleted values, which are only constructed and never copied or destroyed. RefPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { } bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); } ~RefPtr() { if (T* ptr = m_ptr) ptr->deref(); } template <typename U> RefPtr(const RefPtr<U>& o) : m_ptr(o.get()) { if (T* ptr = m_ptr) ptr->ref(); } T* get() const { return m_ptr; } void clear() { if (T* ptr = m_ptr) ptr->deref(); m_ptr = 0; } PassRefPtr<T> release() { PassRefPtr<T> tmp = adoptRef(m_ptr); m_ptr = 0; return tmp; } T& operator*() const { return *m_ptr; } ALWAYS_INLINE T* operator->() const { return m_ptr; } bool operator!() const { return !m_ptr; } // This conversion operator allows implicit conversion to bool but not to other integer types. typedef T* RefPtr::*UnspecifiedBoolType; operator UnspecifiedBoolType() const { return m_ptr ? &RefPtr::m_ptr : 0; } RefPtr& operator=(const RefPtr&); RefPtr& operator=(T*); RefPtr& operator=(const PassRefPtr<T>&); template <typename U> RefPtr& operator=(const RefPtr<U>&); template <typename U> RefPtr& operator=(const PassRefPtr<U>&); void swap(RefPtr&); private: static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); } T* m_ptr; }; template <typename T> template <typename U> inline RefPtr<T>::RefPtr(const PassRefPtr<U>& o) : m_ptr(o.releaseRef()) { } template <typename T> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr<T>& o) { T* optr = o.get(); if (optr) optr->ref(); T* ptr = m_ptr; m_ptr = optr; if (ptr) ptr->deref(); return *this; } template <typename T> template <typename U> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr<U>& o) { T* optr = o.get(); if (optr) optr->ref(); T* ptr = m_ptr; m_ptr = optr; if (ptr) ptr->deref(); return *this; } template <typename T> inline RefPtr<T>& RefPtr<T>::operator=(T* optr) { if (optr) optr->ref(); T* ptr = m_ptr; m_ptr = optr; if (ptr) ptr->deref(); return *this; } template <typename T> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<T>& o) { T* ptr = m_ptr; m_ptr = o.releaseRef(); if (ptr) ptr->deref(); return *this; } template <typename T> template <typename U> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<U>& o) { T* ptr = m_ptr; m_ptr = o.releaseRef(); if (ptr) ptr->deref(); return *this; } template <class T> inline void RefPtr<T>::swap(RefPtr<T>& o) { std::swap(m_ptr, o.m_ptr); } template <class T> inline void swap(RefPtr<T>& a, RefPtr<T>& b) { a.swap(b); } template <typename T, typename U> inline bool operator==(const RefPtr<T>& a, const RefPtr<U>& b) { return a.get() == b.get(); } template <typename T, typename U> inline bool operator==(const RefPtr<T>& a, U* b) { return a.get() == b; } template <typename T, typename U> inline bool operator==(T* a, const RefPtr<U>& b) { return a == b.get(); } template <typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const RefPtr<U>& b) { return a.get() != b.get(); } template <typename T, typename U> inline bool operator!=(const RefPtr<T>& a, U* b) { return a.get() != b; } template <typename T, typename U> inline bool operator!=(T* a, const RefPtr<U>& b) { return a != b.get(); } template <typename T, typename U> inline RefPtr<T> static_pointer_cast(const RefPtr<U>& p) { return RefPtr<T>(static_cast<T*>(p.get())); } template <typename T, typename U> inline RefPtr<T> const_pointer_cast(const RefPtr<U>& p) { return RefPtr<T>(const_cast<T*>(p.get())); } template <typename T> inline T* getPtr(const RefPtr<T>& p) { return p.get(); } } // namespace WTF using WTF::RefPtr; using WTF::static_pointer_cast; using WTF::const_pointer_cast; #endif // WTF_RefPtr_h