MFC中一个链表的实现

// blogListTest.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <stddef.h>
#include <Windows.h>
#include <iostream>
using namespace std;
//MFC中链表的实现
class CMySimpleList
{
public:
CMySimpleList(int nNextOffset = 0);
void Construct(int nNextOffset);
BOOL IsEmpty(void) const;
void AddHead(void* p);
void RemoveAll(void);
void* GetHead(void) const;
void* GetNext(void* p) const;
BOOL Remove(void* p);
public:
void* m_pHead;
size_t m_nNextOffset;
void** GetNextPtr(void* p) const;
};
CMySimpleList::CMySimpleList(int nNextOffset) : m_nNextOffset(nNextOffset), m_pHead(NULL)
{
}
void CMySimpleList::Construct(int nNextOffset)
{
m_nNextOffset = nNextOffset;
}
BOOL CMySimpleList::IsEmpty() const
{
return (NULL == m_pHead);
}
void CMySimpleList::AddHead(void* p)
{
*GetNextPtr(p) = m_pHead;
m_pHead = p;
}
void* CMySimpleList::GetHead(void) const
{
return m_pHead;
}

void* CMySimpleList::GetNext(void* p) const
{
return *GetNextPtr(p);
}
BOOL CMySimpleList::Remove(void* p)
{
BOOL bRet = FALSE;

if (NULL == p)
{
goto Exit0;
}
if (p == m_pHead)
{
m_pHead = *GetNextPtr(p);
bRet = TRUE;
}
else
{
void* pTmp = m_pHead;
while (pTmp != NULL && *GetNextPtr(pTmp) != p)
{
pTmp = *GetNextPtr(pTmp);
}
if (pTmp != NULL)
{
*GetNextPtr(pTmp) = *GetNextPtr(p);
bRet = TRUE;
}
}
Exit0:
return bRet;
}

void CMySimpleList::RemoveAll(void)
{
m_pHead = NULL;
}

void** CMySimpleList::GetNextPtr(void* p) const
{
return (void**)((BYTE*)p + m_nNextOffset);
}
//对上面的代码再进行一次封装
template<class TYPE>
class CMyTypedSimpleList : public CMySimpleList
{
public:
CMyTypedSimpleList(int nNextOffset = 0) : CMySimpleList(nNextOffset)
{

}
TYPE GetHead(void)
{
return (TYPE)CMySimpleList::GetHead();
}
TYPE GetNext(TYPE p)
{
return (TYPE)CMySimpleList::GetNext((void*)p);
}
BOOL Remove(TYPE p)
{
return CMySimpleList::Remove((void*)p);
}
operator TYPE()
{
return (TYPE)CMySimpleList::GetHead();
}

};
struct MyData
{
MyData* pNext;
int nSomeData;
};
int _tmain(int argc, _TCHAR* argv[])
{
/*
CMySimpleList myList;
MyData* pMyData = NULL;
myList.Construct(offsetof(MyData, pNext));
for (int i = 0; i < 10; i++)
{
pMyData = new MyData;
pMyData->nSomeData = i;
myList.AddHead(pMyData);
}
pMyData = (MyData*)myList.GetHead();

while(pMyData != NULL)
{
MyData* pTmp =  pMyData->pNext;
cout << pMyData->nSomeData << endl;
delete pMyData;
pMyData = pTmp;
}
*/
CMyTypedSimpleList<MyData*> myList;
MyData* pMyData = NULL;
myList.Construct(offsetof(MyData, pNext));
for (int i = 0; i < 10; i++)
{
pMyData = new MyData;
pMyData->nSomeData = i;
myList.AddHead(pMyData);
}
//pMyData = myList.GetHead();
pMyData = myList;
while(pMyData != NULL)
{
MyData* pTmp =  pMyData->pNext;
cout << pMyData->nSomeData << endl;
delete pMyData;
pMyData = pTmp;
}
return 0;
}