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 #ifndef WTF_PassRefPtr_h
22 #define WTF_PassRefPtr_h
24 #include <wtf/AlwaysInline.h>
25 #include <wtf/NullPtr.h>
29 template<typename T> class RefPtr;
30 template<typename T> class PassRefPtr;
31 template<typename T> PassRefPtr<T> adoptRef(T*);
33 inline void adopted(const void*) { }
35 #if !(PLATFORM(QT) && CPU(ARM))
36 #define REF_DEREF_INLINE ALWAYS_INLINE
38 // Older version of gcc used by Harmattan SDK fails to build with ALWAYS_INLINE.
39 // See https://bugs.webkit.org/show_bug.cgi?id=37253 for details.
40 #define REF_DEREF_INLINE inline
43 template<typename T> REF_DEREF_INLINE void refIfNotNull(T* ptr)
49 template<typename T> REF_DEREF_INLINE void derefIfNotNull(T* ptr)
55 #undef REF_DEREF_INLINE
57 template<typename T> class PassRefPtr {
59 PassRefPtr() : m_ptr(0) { }
60 PassRefPtr(T* ptr) : m_ptr(ptr) { refIfNotNull(ptr); }
61 // It somewhat breaks the type system to allow transfer of ownership out of
62 // a const PassRefPtr. However, it makes it much easier to work with PassRefPtr
63 // temporaries, and we don't have a need to use real const PassRefPtrs anyway.
64 PassRefPtr(const PassRefPtr& o) : m_ptr(o.leakRef()) { }
65 template<typename U> PassRefPtr(const PassRefPtr<U>& o) : m_ptr(o.leakRef()) { }
67 ALWAYS_INLINE ~PassRefPtr() { derefIfNotNull(m_ptr); }
69 template<typename U> PassRefPtr(const RefPtr<U>&);
71 T* get() const { return m_ptr; }
73 T* leakRef() const WARN_UNUSED_RETURN;
75 T& operator*() const { return *m_ptr; }
76 T* operator->() const { return m_ptr; }
78 bool operator!() const { return !m_ptr; }
80 // This conversion operator allows implicit conversion to bool but not to other integer types.
81 typedef T* (PassRefPtr::*UnspecifiedBoolType);
82 operator UnspecifiedBoolType() const { return m_ptr ? &PassRefPtr::m_ptr : 0; }
84 PassRefPtr& operator=(const PassRefPtr&) { COMPILE_ASSERT(!sizeof(T*), PassRefPtr_should_never_be_assigned_to); return *this; }
86 friend PassRefPtr adoptRef<T>(T*);
89 // adopting constructor
90 PassRefPtr(T* ptr, bool) : m_ptr(ptr) { }
95 template<typename T> template<typename U> inline PassRefPtr<T>::PassRefPtr(const RefPtr<U>& o)
102 template<typename T> inline T* PassRefPtr<T>::leakRef() const
109 template<typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, const PassRefPtr<U>& b)
111 return a.get() == b.get();
114 template<typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, const RefPtr<U>& b)
116 return a.get() == b.get();
119 template<typename T, typename U> inline bool operator==(const RefPtr<T>& a, const PassRefPtr<U>& b)
121 return a.get() == b.get();
124 template<typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, U* b)
129 template<typename T, typename U> inline bool operator==(T* a, const PassRefPtr<U>& b)
134 template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const PassRefPtr<U>& b)
136 return a.get() != b.get();
139 template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const RefPtr<U>& b)
141 return a.get() != b.get();
144 template<typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const PassRefPtr<U>& b)
146 return a.get() != b.get();
149 template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, U* b)
154 template<typename T, typename U> inline bool operator!=(T* a, const PassRefPtr<U>& b)
159 template<typename T> inline PassRefPtr<T> adoptRef(T* p)
162 return PassRefPtr<T>(p, true);
165 template<typename T, typename U> inline PassRefPtr<T> static_pointer_cast(const PassRefPtr<U>& p)
167 return adoptRef(static_cast<T*>(p.leakRef()));
170 template<typename T, typename U> inline PassRefPtr<T> const_pointer_cast(const PassRefPtr<U>& p)
172 return adoptRef(const_cast<T*>(p.leakRef()));
175 template<typename T> inline T* getPtr(const PassRefPtr<T>& p)
182 using WTF::PassRefPtr;
184 using WTF::static_pointer_cast;
185 using WTF::const_pointer_cast;
187 #endif // WTF_PassRefPtr_h