簡易版SharedPointer

SharedPointer

#ifndef __SHAREDPOINTER_HPP__
#define __SHAREDPOINTER_HPP__

template <class T>
class SharedPointer
{
public:
   template <class U>
   SharedPointer(U *obj)
   {
      pPointer = obj;
      pReferenceCounter = new unsigned long;
      (*pReferenceCounter) = 1;
   }
   SharedPointer(const SharedPointer<T>& sharedPointer)
   {
      pPointer = sharedPointer.pPointer;
      pReferenceCounter = sharedPointer.pReferenceCounter;
      (*pReferenceCounter) ++;
   }
   SharedPointer<T>& operator=(const SharedPointer<T>& sharedPointer)
   {
      pPointer = sharedPointer.pPointer;
      pReferenceCounter = sharedPointer.pReferenceCounter;
      (*pReferenceCounter) ++;
      return *this;
   }
   T* get() const
   {
      return pPointer;
   }

   T* operator->() const
   {
      return pPointer;
   }
   
   T& operator*() const
   {
      return *pPointer;
   }
   
   ~SharedPointer()
   {
      (*pReferenceCounter) --;
      if((*pReferenceCounter) == 0) {
         delete pPointer;
         delete pReferenceCounter;
      }
   }
private:
   unsigned long *pReferenceCounter;
   T* pPointer;
};

#endif // __SHAREDPOINTER_HPP__