Easy way to check memory leak

Instead of overload new operator by ourself, we can use visual studio debugger and  c runtime library to detect memory leak.

#ifdef _DEBUG

#define new DEBUG_NEW

#undef THIS_FILE

static char THIS_FILE[] = __FILE__;

#endif

#if defined(_DEBUG) && !defined(DEBUG_NEW)

#define _CRTDBG_MAP_ALLOC

#include < stdlib.h > 

#include < crtdbg.h >

#define DEBUG_NEW new(_NORMAL_BLOCK,THIS_FILE,__LINE__)

#endif

crtdbg.h gives debug version  of malloc and free function and these functions can track memory leak in debug mode. 

Next add _CrtDumpMemoryLeaks() in the place where you want to check memory leak.

If memory leak happens you will get info like this:

d:\l\projects\myprogram\dxengine\dxengine\dxengine\stdafx.h(121) : {216} normal block at 0x009C7B10, 20 bytes long.

 Data: <        <       > 00 05 00 00 20 03 00 00 3C 00 00 00 16 00 00 00

Next according to the memory leak block number 216,add this line at the beginning of the program to tell application to break on the memory leak point.

_CrtSetBreakAlloc(216);

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