Simple Linked List Implementation

The following is extracted from the MFC code to implement the linked list function in the simplest way:

#include <windows.h>#include <stddef.h>#include <stdio.h>#define AFX_INLINE inline /*__forceinline*/#define ASSERT(f)          ((void)0)#define AFX_NOVTABLE#define DEBUG_ONLY(f)      (f)class CSimpleList{public:    CSimpleList(int nNextOffset = 0);    void Construct(int nNextOffset);        // Operations    BOOL IsEmpty() const;    void AddHead(void* p);    void RemoveAll();    void* GetHead() const;    void* GetNext(void* p) const;    BOOL Remove(void* p);        // Implementation    void* m_pHead;    size_t m_nNextOffset;        void** GetNextPtr(void* p) const;   // somewhat trusting...};AFX_INLINE CSimpleList::CSimpleList(int nNextOffset){    m_pHead = NULL;     m_nNextOffset = nNextOffset; }AFX_INLINE void CSimpleList::Construct(int nNextOffset){     ASSERT(m_pHead == NULL);     m_nNextOffset = nNextOffset; }AFX_INLINE BOOL CSimpleList::IsEmpty() const{    return m_pHead == NULL; }void CSimpleList::AddHead(void* p){    ASSERT(p != NULL);    ASSERT(*GetNextPtr(p) == NULL);        *GetNextPtr(p) = m_pHead;    m_pHead = p;}AFX_INLINE void** CSimpleList::GetNextPtr(void* p) const{     ASSERT(p != NULL);     return (void**)((BYTE*)p+m_nNextOffset); }AFX_INLINE void CSimpleList::RemoveAll(){    m_pHead = NULL; }AFX_INLINE void* CSimpleList::GetHead() const{    return m_pHead; }AFX_INLINE void* CSimpleList::GetNext(void* prevElement) const{    return *GetNextPtr(prevElement); }BOOL CSimpleList::Remove(void* p){    ASSERT(p != NULL);        if (m_pHead == NULL)        return FALSE;        BOOL bResult = FALSE;    if (m_pHead == p)    {        m_pHead = *GetNextPtr(p);        DEBUG_ONLY(*GetNextPtr(p) = NULL);        bResult = TRUE;    }    else    {        void* pTest = m_pHead;        while (pTest != NULL && *GetNextPtr(pTest) != p)            pTest = *GetNextPtr(pTest);        if (pTest != NULL)        {            *GetNextPtr(pTest) = *GetNextPtr(p);            DEBUG_ONLY(*GetNextPtr(p) = NULL);            bResult = TRUE;        }    }    return bResult;}template<class TYPE>class CTypedSimpleList : public CSimpleList{public:    CTypedSimpleList(int nNextOffset = 0)        : CSimpleList(nNextOffset) { }    void AddHead(TYPE p)    { CSimpleList::AddHead(p); }    TYPE GetHead()    { return (TYPE)CSimpleList::GetHead(); }    TYPE GetNext(TYPE p)    { return (TYPE)CSimpleList::GetNext(p); }    BOOL Remove(TYPE p)    { return CSimpleList::Remove((TYPE)p); }    operator TYPE()    { return (TYPE)CSimpleList::GetHead(); }};class AFX_NOVTABLE CNoTrackObject{public:    void* PASCAL operator new(size_t nSize)    {        void* p = ::LocalAlloc(LPTR, nSize);//         if (p == NULL)//             AfxThrowMemoryException();        return p;    }    void PASCAL operator delete(void* p)    {        if (p != NULL)            ::LocalFree(p);    }        void PASCAL operator delete(void* pObject, LPCSTR, int)    {        if (pObject != NULL)            ::LocalFree(pObject);    }    virtual ~CNoTrackObject() { }};struct CThreadData : public CNoTrackObject{    CThreadData* pNext; // required to be member of CSimpleList    int nCount;         // current size of pData    LPVOID* pData;      // actual thread local data (indexed by nSlot)};int main(int argc, char* argv[]){    CTypedSimpleList<CThreadData*> m_list;  // list of CThreadData structures    m_list.Construct(offsetof(CThreadData, pNext));    for (int i = 0; i < 10; i++)    {        CThreadData *p = new CThreadData;        p->nCount = i;        p->pData = NULL;        m_list.AddHead(p);    }    CThreadData *p = m_list.GetHead();    while (p != NULL)    {        printf("%d ", p->nCount);        p = p->pNext;//        p = m_list.GetNext(p);    }    return 0;}

 

Simple Linked List Implementation