C / C++ / MFC

while(*dst++=*src++); /* copy string src to dst */

class CBuffer
{
public:
   virtual void Set() = 0;
   virtual void Get() = 0;
   ...
};
 
template<class TBuffer> 
class CUndoBuffer
{
public:
   ...
   void SomeFunc()
   {
      m_theBuffer.Set( whatever );
      m_theBuffer.Get( whatever );
   }
 
private:
   TBuffer m_theBuffer;
};
 
class CConcreteBuffer : public CBuffer
{
public:
   virtual void Set();
   virtual void Get();
   ...
};
 
CUndoBuffer<CConcreteBuffer> AConcreteUndoBuffer;
etc..