A Simple, Action Based, Undo/Redo Framework

/*
***************************************************************************

kis v 1 r 1

(c) 2002-2009, Florin DUMITRESCU

mailto: fdproxy@gmail.com

$Workfile: kis_SharedPtr.h $ 

***************************************************************************
*/


#ifndef _KIS_SHARED_PTR_H_
#define _KIS_SHARED_PTR_H_


KIS_BEG


//-------------------------------------------------------------------------
/** [To be supplied.] */
template < class T >
class C_SharedPtr
{

public:

  explicit C_SharedPtr()
  :
  m_p( 0 )
  {
    // nop
  }

  explicit C_SharedPtr( T* a_p ) 
  :
  m_p( a_p )
  {
    _AddRef();
  }

  C_SharedPtr( const C_SharedPtr<T>& a_s )
  :
  m_p( a_s.m_p )
  {
    _AddRef();
  }

  ~C_SharedPtr()
  {
    _Release();
  }

  T* operator->()
  {
    return m_p;
  }

  const T* operator->() const
  {
    return m_p;
  }

  C_SharedPtr<T>& operator=( const C_SharedPtr<T>& a_r )
  {
    if ( m_p != a_r.m_p )
    {
      _Release();
      m_p = a_r.m_p;
      _AddRef();
    }
    return *this;
  }

  operator bool() const
  {
    return m_p != 0;
  }

protected:

  T* m_p;

  void _AddRef()
  {
    if ( m_p )
      m_p->AddRef();
  }

  void _Release()
  {
    if ( m_p )
      m_p->Release();
    m_p = 0;
  }

};


KIS_END


#endif  _KIS_SHARED_PTR_H_