IOFFSETOF ICONTAINEROF IQUEUE_ENTRY

#include <iostream>

#define IOFFSETOF(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

#define ICONTAINEROF(ptr, type, member) ((type*)(((char*)((type*)ptr)) - IOFFSETOF(type, member)) )

#define IQUEUE_ENTRY(ptr, type, member) ICONTAINEROF(ptr, type, member)

using namespace std;

int main(){

    struct Demo{
        char sex;
        int  id;
    };

   struct Demo dd = {'0',666};

    cout << "&dd                        : " << &dd << endl;
    cout << "IQUEUE_ENTRY(&dd,Demo,sex) : " << IQUEUE_ENTRY(&dd.sex,Demo,sex) << endl;
    cout << "IQUEUE_ENTRY(&dd,Demo,id)  : " << IQUEUE_ENTRY(&dd.id ,Demo, id) << endl;
    return 0;
}

输出:

    IQUEUE_ENTRY作用:根据结构体的某个数据成员，输出结构体的起始地址。

　

#define IOFFSETOF(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

　

IOFFSETOF:解析参考https://www.cnblogs.com/iuyy/p/13391851.html