GNU CommonC++

pointer.h

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00001 // Copyright (C) 2001-2005 Open Source Telecom Corporation.
00002 // Copyright (C) 2006-2010 David Sugar, Tycho Softworks.
00003 //
00004 // This program is free software; you can redistribute it and/or modify
00005 // it under the terms of the GNU General Public License as published by
00006 // the Free Software Foundation; either version 2 of the License, or
00007 // (at your option) any later version.
00008 //
00009 // This program is distributed in the hope that it will be useful,
00010 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00011 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00012 // GNU General Public License for more details.
00013 //
00014 // You should have received a copy of the GNU General Public License
00015 // along with this program; if not, write to the Free Software
00016 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
00017 //
00018 // As a special exception to the GNU General Public License, permission is
00019 // granted for additional uses of the text contained in its release
00020 // of Common C++.
00021 //
00022 // The exception is that, if you link the Common C++ library with other
00023 // files to produce an executable, this does not by itself cause the
00024 // resulting executable to be covered by the GNU General Public License.
00025 // Your use of that executable is in no way restricted on account of
00026 // linking the Common C++ library code into it.
00027 //
00028 // This exception does not however invalidate any other reasons why
00029 // the executable file might be covered by the GNU General Public License.
00030 //
00031 // This exception applies only to the code released under the
00032 // name Common C++.  If you copy code from other releases into a copy of
00033 // Common C++, as the General Public License permits, the exception does
00034 // not apply to the code that you add in this way.  To avoid misleading
00035 // anyone as to the status of such modified files, you must delete
00036 // this exception notice from them.
00037 //
00038 // If you write modifications of your own for Common C++, it is your choice
00039 // whether to permit this exception to apply to your modifications.
00040 // If you do not wish that, delete this exception notice.
00041 
00047 #ifndef CCXX_POINTER_H_
00048 #define CCXX_POINTER_H_
00049 
00050 #ifndef CCXX_MISSING_H_
00051 #include <cc++/missing.h>
00052 #endif
00053 
00054 #ifdef  CCXX_NAMESPACES
00055 namespace ost {
00056 #endif
00057 
00064 template <class T>
00065 class Pointer
00066 {
00067 protected:
00068     unsigned *ptrCount;
00069     T *ptrObject;
00070 
00071     void ptrDetach(void)
00072     {
00073         if(ptrCount && --(*ptrCount)==0) {
00074             delete ptrObject;
00075             delete ptrCount;
00076         }
00077         ptrObject = NULL;
00078         ptrCount = NULL;
00079     }
00080 
00081 public:
00082     explicit Pointer(T* ptr = NULL) : ptrObject(ptr)
00083     {
00084         ptrCount = new unsigned;
00085         *ptrCount = 1;
00086     }
00087 
00088     Pointer(const Pointer<T> &ref)
00089     {
00090         ptrObject = ref.ptrObject;
00091         ptrCount = ref.ptrCount;
00092         ++(*ptrCount);
00093     }
00094 
00095     inline virtual ~Pointer()
00096         {ptrDetach();}
00097 
00098 
00099     Pointer& operator=(const Pointer<T> &ref)
00100     {
00101         if(this != &ref) {
00102             ptrDetach();
00103             ptrObject = ref.ptrObject;
00104             ptrCount = ref.ptrCount;
00105             ++(*ptrCount);
00106         }
00107         return *this;
00108     }
00109 
00110     inline T& operator*() const
00111         {return *ptrObject;};
00112 
00113     inline T* getObject() const
00114         {return ptrObject;};
00115 
00116     inline T* operator->() const
00117         {return ptrObject;};
00118 
00119     inline bool operator!() const
00120         {return (*ptrCount == 1);};
00121 
00122     inline int operator++() const
00123         {return ++(*ptrCount);};
00124 
00125     int operator--() const
00126     {
00127         if(*ptrCount == 1) {
00128             delete this;
00129             return 0;
00130         }
00131         return --(*ptrCount);
00132     }
00133 };
00134 
00135 #ifdef  CCXX_NAMESPACES
00136 }
00137 #endif
00138 
00139 #endif