WTF

RefPtr.h

00001 // -*- mode: c++; c-basic-offset: 4 -*-
00002 /*
00003  *  This file is part of the KDE libraries
00004  *  Copyright (C) 2005, 2006 Apple Computer, Inc.
00005  *
00006  *  This library is free software; you can redistribute it and/or
00007  *  modify it under the terms of the GNU Library General Public
00008  *  License as published by the Free Software Foundation; either
00009  *  version 2 of the License, or (at your option) any later version.
00010  *
00011  *  This library is distributed in the hope that it will be useful,
00012  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  *  Library General Public License for more details.
00015  *
00016  *  You should have received a copy of the GNU Library General Public License
00017  *  along with this library; see the file COPYING.LIB.  If not, write to
00018  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
00019  *  Boston, MA 02110-1301, USA.
00020  *
00021  */
00022 
00023 #ifndef WTF_RefPtr_h
00024 #define WTF_RefPtr_h
00025 
00026 #include <algorithm>
00027 #include "PassRefPtr.h"
00028 
00029 namespace WTF {
00030 
00031     template <typename T> class PassRefPtr;
00032 
00033     template <typename T> class RefPtr
00034     {
00035     public:
00036         RefPtr() : m_ptr(0) {}
00037         RefPtr(T& ptr) : m_ptr(&ptr) {}
00038         RefPtr(T *ptr) : m_ptr(ptr) { if (ptr) ptr->ref(); }
00039         RefPtr(const RefPtr& o) : m_ptr(o.m_ptr) { if (T *ptr = m_ptr) ptr->ref(); }
00040         // see comment in PassRefPtr.h for why this takes const reference
00041         template <typename U> RefPtr(const PassRefPtr<U>&);
00042 
00043         ~RefPtr() { if (T *ptr = m_ptr) ptr->deref(); }
00044         
00045         template <typename U> RefPtr(const RefPtr<U>& o) : m_ptr(o.get()) { if (T *ptr = m_ptr) ptr->ref(); }
00046         
00047         T *get() const { return m_ptr; }
00048         
00049         void assign(T& ptr) { m_ptr = &ptr; }
00050         void retain(T& ptr) { m_ptr = &ptr; ptr.ref(); }
00051         void reset(T& ptr) { T* optr = m_ptr; m_ptr = &ptr; if (optr) optr->deref(); }
00052         PassRefPtr<T> release() { PassRefPtr<T> tmp = adoptRef(m_ptr); m_ptr = 0; return tmp; }
00053 
00054         T& operator*() const { return *m_ptr; }
00055         T *operator->() const { return m_ptr; }
00056         
00057         bool operator!() const { return !m_ptr; }
00058     
00059         // This conversion operator allows implicit conversion to bool but not to other integer types.
00060         typedef T * (RefPtr::*UnspecifiedBoolType)() const;
00061         operator UnspecifiedBoolType() const { return m_ptr ? &RefPtr::get : 0; }
00062         
00066         RefPtr& operator=(const RefPtr&);
00067         RefPtr& operator=(T *);
00068         RefPtr& operator=(const PassRefPtr<T>&);
00069         RefPtr& operator=(T& ptr) { T* optr = m_ptr; m_ptr = &ptr; if (optr) optr->deref(); return *this; }
00070 
00074         template <typename U> RefPtr& operator=(const RefPtr<U>&);
00075         template <typename U> RefPtr& operator=(const PassRefPtr<U>&);
00076 
00077         void swap(RefPtr&);
00078 
00079     private:
00080         T *m_ptr;
00081     };
00082     
00083     template <typename T> template <typename U> inline RefPtr<T>::RefPtr(const PassRefPtr<U>& o)
00084         : m_ptr(o.release())
00085     {
00086     }
00087 
00088     template <typename T> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr<T>& o)
00089     {
00090         T* optr = o.get();
00091         if (optr)
00092             optr->ref();
00093         T* ptr = m_ptr;
00094         m_ptr = optr;
00095         if (ptr)
00096             ptr->deref();
00097         return *this;
00098     }
00099     
00100     template <typename T> template <typename U> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr<U>& o)
00101     {
00102         T* optr = o.get();
00103         if (optr)
00104             optr->ref();
00105         T* ptr = m_ptr;
00106         m_ptr = optr;
00107         if (ptr)
00108             ptr->deref();
00109         return *this;
00110     }
00111     
00112     template <typename T> inline RefPtr<T>& RefPtr<T>::operator=(T* optr)
00113     {
00114         if (optr)
00115             optr->ref();
00116         T* ptr = m_ptr;
00117         m_ptr = optr;
00118         if (ptr)
00119             ptr->deref();
00120         return *this;
00121     }
00122 
00123     template <typename T> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<T>& o)
00124     {
00125         T* ptr = m_ptr;
00126         m_ptr = o.release();
00127         if (ptr)
00128             ptr->deref();
00129         return *this;
00130     }
00131 
00132     template <typename T> template <typename U> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<U>& o)
00133     {
00134         T* ptr = m_ptr;
00135         m_ptr = o.release();
00136         if (ptr)
00137             ptr->deref();
00138         return *this;
00139     }
00140 
00141     template <class T> inline void RefPtr<T>::swap(RefPtr<T>& o)
00142     {
00143         std::swap(m_ptr, o.m_ptr);
00144     }
00145 
00146     template <class T> inline void swap(RefPtr<T>& a, RefPtr<T>& b)
00147     {
00148         a.swap(b);
00149     }
00150 
00151     template <typename T, typename U> inline bool operator==(const RefPtr<T>& a, const RefPtr<U>& b)
00152     { 
00153         return a.get() == b.get(); 
00154     }
00155 
00156     template <typename T, typename U> inline bool operator==(const RefPtr<T>& a, U* b)
00157     { 
00158         return a.get() == b; 
00159     }
00160     
00161     template <typename T, typename U> inline bool operator==(T* a, const RefPtr<U>& b) 
00162     {
00163         return a == b.get(); 
00164     }
00165     
00166     template <typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const RefPtr<U>& b)
00167     { 
00168         return a.get() != b.get(); 
00169     }
00170 
00171     template <typename T, typename U> inline bool operator!=(const RefPtr<T>& a, U* b)
00172     {
00173         return a.get() != b; 
00174     }
00175 
00176     template <typename T, typename U> inline bool operator!=(T* a, const RefPtr<U>& b)
00177     { 
00178         return a != b.get(); 
00179     }
00180     
00181     template <typename T, typename U> inline RefPtr<T> static_pointer_cast(const RefPtr<U>& p)
00182     { 
00183         return RefPtr<T>(static_cast<T *>(p.get())); 
00184     }
00185 
00186     template <typename T, typename U> inline RefPtr<T> const_pointer_cast(const RefPtr<U>& p)
00187     { 
00188         return RefPtr<T>(const_cast<T *>(p.get())); 
00189     }
00190 
00191 } // namespace WTF
00192 
00193 using WTF::RefPtr;
00194 using WTF::static_pointer_cast;
00195 using WTF::const_pointer_cast;
00196 
00197 #endif // WTF_RefPtr_h
WTF

RefPtr.h

WTF

kdelibs
