2 * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
21 // RefPtr and PassRefPtr are documented at http://webkit.org/coding/RefPtr.html
27 #include <wtf/FastAllocBase.h>
28 #include <wtf/PassRefPtr.h>
32 enum PlacementNewAdoptType { PlacementNewAdopt };
34 template<typename T> class PassRefPtr;
36 enum HashTableDeletedValueType { HashTableDeletedValue };
38 template<typename T> class RefPtr {
39 WTF_MAKE_FAST_ALLOCATED;
41 ALWAYS_INLINE RefPtr() : m_ptr(0) { }
42 ALWAYS_INLINE RefPtr(T* ptr) : m_ptr(ptr) { refIfNotNull(ptr); }
43 ALWAYS_INLINE RefPtr(const RefPtr& o) : m_ptr(o.m_ptr) { refIfNotNull(m_ptr); }
44 template<typename U> RefPtr(const RefPtr<U>& o) : m_ptr(o.get()) { refIfNotNull(m_ptr); }
46 // See comments in PassRefPtr.h for an explanation of why this takes a const reference.
47 template<typename U> RefPtr(const PassRefPtr<U>&);
49 // Special constructor for cases where we overwrite an object in place.
50 ALWAYS_INLINE RefPtr(PlacementNewAdoptType) { }
52 // Hash table deleted values, which are only constructed and never copied or destroyed.
53 RefPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { }
54 bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); }
56 ALWAYS_INLINE ~RefPtr() { derefIfNotNull(m_ptr); }
58 T* get() const { return m_ptr; }
61 PassRefPtr<T> release() { PassRefPtr<T> tmp = adoptRef(m_ptr); m_ptr = 0; return tmp; }
63 T& operator*() const { return *m_ptr; }
64 ALWAYS_INLINE T* operator->() const { return m_ptr; }
66 bool operator!() const { return !m_ptr; }
68 // This conversion operator allows implicit conversion to bool but not to other integer types.
69 typedef T* (RefPtr::*UnspecifiedBoolType);
70 operator UnspecifiedBoolType() const { return m_ptr ? &RefPtr::m_ptr : 0; }
72 RefPtr& operator=(const RefPtr&);
73 RefPtr& operator=(T*);
74 RefPtr& operator=(const PassRefPtr<T>&);
75 #if !COMPILER_SUPPORTS(CXX_NULLPTR)
76 RefPtr& operator=(std::nullptr_t) { clear(); return *this; }
78 template<typename U> RefPtr& operator=(const RefPtr<U>&);
79 template<typename U> RefPtr& operator=(const PassRefPtr<U>&);
83 static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); }
89 template<typename T> template<typename U> inline RefPtr<T>::RefPtr(const PassRefPtr<U>& o)
94 template<typename T> inline void RefPtr<T>::clear()
101 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr<T>& o)
111 template<typename T> template<typename U> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr<U>& o)
121 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(T* optr)
130 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<T>& o)
138 template<typename T> template<typename U> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<U>& o)
146 template<class T> inline void RefPtr<T>::swap(RefPtr<T>& o)
148 std::swap(m_ptr, o.m_ptr);
151 template<class T> inline void swap(RefPtr<T>& a, RefPtr<T>& b)
156 template<typename T, typename U> inline bool operator==(const RefPtr<T>& a, const RefPtr<U>& b)
158 return a.get() == b.get();
161 template<typename T, typename U> inline bool operator==(const RefPtr<T>& a, U* b)
166 template<typename T, typename U> inline bool operator==(T* a, const RefPtr<U>& b)
171 template<typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const RefPtr<U>& b)
173 return a.get() != b.get();
176 template<typename T, typename U> inline bool operator!=(const RefPtr<T>& a, U* b)
181 template<typename T, typename U> inline bool operator!=(T* a, const RefPtr<U>& b)
186 template<typename T, typename U> inline RefPtr<T> static_pointer_cast(const RefPtr<U>& p)
188 return RefPtr<T>(static_cast<T*>(p.get()));
191 template<typename T, typename U> inline RefPtr<T> const_pointer_cast(const RefPtr<U>& p)
193 return RefPtr<T>(const_cast<T*>(p.get()));
196 template<typename T> inline T* getPtr(const RefPtr<T>& p)
204 using WTF::static_pointer_cast;
205 using WTF::const_pointer_cast;
207 #endif // WTF_RefPtr_h