通过地址偏移量访问C++结构体数据成员

#include "stdafx.h"

#include <string>
#include <list>
#include <map>

//获取结构体偏移量宏定义
#define  GetAttrOffSet(CLASSTYPE, Attr)  (size_t)(&((CLASSTYPE*)0x000)->Attr)

//内存模型对象
class CNode
{
public:
int m_iAttrOne;
std::string m_strAttrTwo;
std::list<int> m_lstAttrThree;
std::map<int, std::list<int> > m_mapAttrFour;
};

//对象管理器
class CNodeMgr
{
public:
template<class Type>
void ModifyNodeAttr(const Type& attr, const int iNodeID, const size_t offset)
{
//此处略去m_mapNode中找不到iNodeID的异常情况处理
*((Type*)((size_t)m_mapNode[iNodeID] + offset)) = attr;
}

template<class Type>
const Type& GetNodeAttr(const int iNodeID, const size_t offset)
{
//此处略去m_mapNode中找不到iNodeID的异常情况处理
return *((Type*)((size_t)m_mapNode[iNodeID] + offset));
}

CNodeMgr()
{
m_mapNode[1] = new CNode;
m_mapNode[2] = new CNode;
m_mapNode[3] = new CNode;
}

private:
std::map<int, CNode*> m_mapNode;
};

int _tmain(int argc, _TCHAR* argv[])
{
//修改Key值为2的Node对象属性
CNodeMgr nodeMgr;
nodeMgr.ModifyNodeAttr((int)1, 2, GetAttrOffSet(CNode, m_iAttrOne));
nodeMgr.ModifyNodeAttr(std::string("abc"), 2, GetAttrOffSet(CNode, m_strAttrTwo));

std::list<int> lstAttr;
lstAttr.push_back(1);
lstAttr.push_back(2);
lstAttr.push_back(3);
nodeMgr.ModifyNodeAttr(lstAttr, 2, GetAttrOffSet(CNode, m_lstAttrThree));

std::map<int, std::list<int> > mapAttr;
mapAttr[1] = lstAttr;
mapAttr[2] = lstAttr;
nodeMgr.ModifyNodeAttr(mapAttr, 2, GetAttrOffSet(CNode, m_mapAttrFour));

//获取Key值为2的Node属性
lstAttr = nodeMgr.GetNodeAttr<std::list<int>>(2, GetAttrOffSet(CNode, m_lstAttrThree));

return 0;
}