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OgreSharedPtr.h

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00001 /*
00002 -----------------------------------------------------------------------------
00003 This source file is part of OGRE
00004     (Object-oriented Graphics Rendering Engine)
00005 For the latest info, see http://www.ogre3d.org/
00006 
00007 Copyright © 2000-2002 The OGRE Team
00008 Also see acknowledgements in Readme.html
00009 
00010 This program is free software; you can redistribute it and/or modify it under
00011 the terms of the GNU Lesser General Public License as published by the Free Software
00012 Foundation; either version 2 of the License, or (at your option) any later
00013 version.
00014 
00015 This program is distributed in the hope that it will be useful, but WITHOUT
00016 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
00017 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
00018 
00019 You should have received a copy of the GNU Lesser General Public License along with
00020 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
00021 Place - Suite 330, Boston, MA 02111-1307, USA, or go to
00022 http://www.gnu.org/copyleft/lesser.txt.
00023 -----------------------------------------------------------------------------
00024 */
00025 #ifndef __SharedPtr_H__
00026 #define __SharedPtr_H__
00027 
00028 #include "OgrePrerequisites.h"
00029 
00030 namespace Ogre {
00031 
00042     template<class T> class SharedPtr {
00043     protected:
00044         T* pRep;
00045         unsigned int* pUseCount;
00046     public:
00051         SharedPtr() : pRep(0), pUseCount(0) {}
00052         SharedPtr(T* rep) : pRep(rep), pUseCount(new unsigned int(1)) {}
00053         SharedPtr(const SharedPtr& r) : pRep(r.pRep), pUseCount(r.pUseCount) { 
00054             // Handle zero pointer gracefully to manage STL containers
00055             if(pUseCount)
00056             {
00057                 ++(*pUseCount); 
00058             }
00059         }
00060         SharedPtr& operator=(const SharedPtr& r) {
00061             if (pRep == r.pRep)
00062                 return *this;
00063             release();
00064             pRep = r.pRep;
00065             pUseCount = r.pUseCount;
00066             if (pUseCount)
00067             {
00068                 ++(*pUseCount);
00069             }
00070             return *this;
00071         }
00072         virtual ~SharedPtr() {
00073             release();
00074         }
00075 
00076 
00077         inline T& operator*() const { assert(pRep); return *pRep; }
00078         inline T* operator->() const { assert(pRep); return pRep; }
00079         inline T* get() const { assert(pRep); return pRep; }
00080 
00085         void bind(T* rep) {
00086             assert(!pRep && !pUseCount);
00087             pUseCount = new unsigned int(1);
00088             pRep = rep;
00089         }
00090 
00091         inline bool unique() const { assert(pUseCount); return *pUseCount == 1; }
00092         inline unsigned int useCount() const { assert(pUseCount); return *pUseCount; }
00093 
00094         inline T* getPointer() const { assert(pRep); return pRep; }
00095 
00096         inline bool isNull(void) const { return pRep == 0; }
00097 
00098         inline void setNull(void) { 
00099             release();
00100             pRep = 0;
00101             pUseCount = 0;
00102         }
00103 
00104     protected:
00105 
00106         inline void release(void) {
00107             if (pUseCount)
00108             {
00109                 if (--(*pUseCount) == 0) {
00110                     destroy();
00111                 }
00112             }
00113         }
00114 
00115         virtual void destroy(void)
00116         {
00117             delete pRep;
00118             delete pUseCount;
00119         }
00120     };
00121 
00122     template<class T, class U> inline bool operator==(SharedPtr<T> const& a, SharedPtr<U> const& b)
00123     {
00124         return a.get() == b.get();
00125     }
00126 
00127     template<class T, class U> inline bool operator!=(SharedPtr<T> const& a, SharedPtr<U> const& b)
00128     {
00129         return a.get() != b.get();
00130     }
00131 
00132 }
00133 
00134 #endif

Copyright © 2002-2003 by The OGRE Team
Last modified Sun Nov 28 19:48:46 2004