Setting memory allocation break point in watch window

This tip helps to utilize the contex operator :

{,,msvcrxxd.dll}_crtBreakAlloc

Memory leaks in VC++ can be detected using debug heap function. To enable these, we should use:

#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>

// Note that in the above code, the order of #include statements must not change

And to track memory (leaks) allocated via 'new', we can use:

#ifdef _DEBUG
#define DEBUG_NEW new(_NORMAL_BLOCK, __FILE__, __LINE__)
#define new DEBUG_NEW
#endif

Now at the end of main() or at the point of interest in the code, we should call _CrtDumpMemoryLeaks();

void main()
{
   // ....
  _CrtDumpMemoryLeaks();
}

The leaks, if any, are shown in the Output window as:

C:\Projects\Sample\main.cpp(10) : {30} normal block at 0x00780E80, 64 bytes long.
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We can utilize the memory allocation number (30 in the above example) to identify the code which caused the leak. To do this, we can use _crtBreakAlloc or the context operator in the watch window:

{,,msvcrxxd.dll}_crtBreakAlloc

Here xx should be replaced by the version of Visual Studio. 90 for VS2008 80 for VS2005 ... In the watch window, the value of this wil be -1 initially and we can then set it to our memory allocation number to break at the appropiate code block. To consolidate, all we have to do is this:

#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>

void main()
{
   int* i = new int;
   // .....
   // the memory allocated with pointer i is not released and will be shown as leak
  _CrtDumpMemoryLeaks();
}

Hope now it is usable in the real world.