DBLIST.H

#ifndef __DBLIST_H__ 
#define __DBLIST_H__ 
 
#include "debug.h" 
 
#ifndef __cplusplus 
#error DBList.h included from a C file! 
#endif 
 
//forward declaration of template used as friend class 
template <class T> class DbLinkedList; 
 
template<class A> 
class DblNode 
{ 
friend class DbLinkedList<A>; 
 
private: 
    class DblNode<A>    *pNext; 
    class DblNode<A>    *pPrev; 
 
    A       value; 
}; 
 
template <class T> 
class DbLinkedList 
{ 
private: 
 
public: 
    DbLinkedList(); 
    DbLinkedList( T emptyElt ); 
    ~DbLinkedList(); 
 
    inline void SetEmpty( T emptyElt ) { m_emptyT = emptyElt; } 
 
    inline BOOL IsAtTail()  { ASSERT( NULL != m_pCurrent ); 
                    return (m_pCurrent->pNext == NULL); } 
 
    void Clear( void ); 
    void RemoveCurrent(); 
    void Remove( T ); 
    BOOL InsertAfterCurrent( T val ); 
    BOOL InsertBeforeCurrent( T val ); 
    T GetCurrent(); 
    void Append( T ); 
 
    inline void SetAtHead()     { m_pCurrent = m_pHead; } 
    inline void SetAtTail()     { m_pCurrent = m_pTail; } 
 
    void AssertValid(); 
 
    inline int GetElementCount( void )  { return m_nElementCount; } 
 
    DbLinkedList<T> &operator++() 
        { if( m_pCurrent && m_pCurrent->pNext ) m_pCurrent = m_pCurrent->pNext; return *this; } 
    DbLinkedList<T> &operator++( int ) 
        { if( m_pCurrent && m_pCurrent->pNext ) m_pCurrent = m_pCurrent->pNext; return *this; } 
    DbLinkedList<T> &operator--() 
        { if( m_pCurrent && m_pCurrent->pPrev ) m_pCurrent = m_pCurrent->pPrev; return *this; } 
    DbLinkedList<T> &operator--( int ) 
        { if( m_pCurrent && m_pCurrent->pPrev ) m_pCurrent = m_pCurrent->pPrev; return *this; } 
 
 
protected: 
    DblNode<T>  *m_pHead; 
    DblNode<T>  *m_pTail; 
    DblNode<T>  *m_pCurrent; 
 
    int m_nElementCount; 
    T   m_emptyT; 
}; 
 
 
// Because of the way templates work, we must include the code from the 
// header file. 
#include "DbList.cpp" 
 
 
#endif