delete pointer causes memory leak?

Question

I am using Run Time Library, CRT, to detect memory leak. Here is what I found in the destructor:

                    _CrtMemCheckpoint(&crtMemStateFinish);
nDifference = _CrtMemDifference(&crtMemStateDifference, &crtMemStateStart, &crtMemStateFinish);
sizeChange = crtMemStateFinish.lSizes - crtMemStateStart.lSizes;
if(nDifference > 0)
_CrtDumpMemoryLeaks();
nDifference = 0;
sizeChange = 0;
_CrtMemCheckpoint(&crtMemStateStart);


                delete[] ptr;
                ptr = NULL;

                    _CrtMemCheckpoint(&crtMemStateFinish);
nDifference = _CrtMemDifference(&crtMemStateDifference, &crtMemStateStart, &crtMemStateFinish);
sizeChange = crtMemStateFinish.lSizes - crtMemStateStart.lSizes;
if(nDifference > 0)
_CrtDumpMemoryLeaks();
nDifference = 0;
sizeChange = 0;
_CrtMemCheckpoint(&crtMemStateStart);

The nDifference > 0, so there is memory leak, but it does not say where.

Here is how ptr is declared and defined:

char ** ptr;

ptr = new char*[4];

Any suggestions?

score 4 · Accepted Answer · answered Nov 22 '13 at 17:06

4

You are allocating an array of pointers. Not only do you have to delete the array, you have to delete each pointer in the array. Obviously you need to do this before you delete the array.

answered Nov 22 '13 at 17:06

Mark Ransom

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@NickXTsui with a `for` loop. – Mark Ransom Nov 22 '13 at 17:07
1

Or use `std::vector` instead – benjymous Nov 22 '13 at 17:08
@benjymous brings up a good point, is there any reason you are not using the `stl`? – ssell Nov 22 '13 at 17:10

delete pointer causes memory leak?

1 Answers1