核心提示：这里是一个简单的内存泄漏自动检查机制。只适用于单线程情况下。工作原理就是将已经分配的内存用一个双向链表串联起来，释放内存时从链表里删除。

　　这里是一个简单的内存泄漏自动检查机制。只适用于单线程情况下。工作原理就是将已经分配的内存用一个双向链表串联起来，释放内存时从链表里删除。在程序退出时，将链表中未释放的内存打印出来。同时在内存块中保存文件名和行号，用于定位内存分配地址。

// placement_new.cpp : Defines the entry point for the console application.#include "stdafx.h"#include#include#define ASSERT assertchar buff[1024];using namespace std;struct MEMORY_TAG{int nSize;const char* szFile;int nLine;MEMORY_TAG* pPrev;MEMORY_TAG* pNext;};MEMORY_TAG g_header = {0, 0, 0, 0, 0};// 打印出所有未释放的内存void DumpUnAllocatedMem(){for(MEMORY_TAG* pEntry = g_header.pNext; pEntry; pEntry = pEntry->pNext){printf("%s(%d) : leak %d bytes ", pEntry->szFile ? pEntry->szFile : "", pEntry->nLine, pEntry->nSize);}}// 统计已经分配的内存块数和字节数int CountOfAllocatedMem(void* pnSize= NULL){int nCount = 0;size_t allocated = 0;for(MEMORY_TAG* pEntry = g_header.pNext; pEntry; pEntry = pEntry->pNext){allocated += pEntry->nSize;nCount++;}printf("%d count, %d total ", nCount, allocated);return nCount;}// 实现一个全局operator new可以有文件名和行号作为参数void* operator new(size_t size, const char* pszFile, int line){size_t nRealSize = size + sizeof(MEMORY_TAG);MEMORY_TAG* pTag = (MEMORY_TAG*)malloc(nRealSize);pTag->nSize = nRealSize;pTag->szFile = pszFile;pTag->nLine = line;// 插入队列头部if (g_header.pNext){g_header.pNext->pPrev = pTag;}pTag->pNext = g_header.pNext;g_header.pNext = pTag;pTag->pPrev = &g_header;return pTag + 1;}void* operator new(size_t size){return (operator new(size, __FILE__, __LINE__));}void operator delete(void* p, const char*, int line){delete p;}void operator delete(void* p){MEMORY_TAG* pTag = (MEMORY_TAG*)(((char*)p)-sizeof(MEMORY_TAG));// 从队列中删除pTag->pPrev->pNext = pTag->pNext;if (pTag->pNext){pTag->pNext->pPrev = pTag->pPrev;}free(pTag);}class Object{