Question

Possible Duplicates:
How can I get the size of an array from a pointer in C?
Is there any way to determine the size of a C++ array programmatically? And if not, why?

I get a pointer to a chunk of allocated memory out of a C style function.
Now, it would be really interesting for debugging purposes to know how
big the allocated memory block that this pointer points is.

Is there anything more elegant than provoking an exception by blindly running over its boundaries?

Thanks in advance,
Andreas

EDIT:

I use VC++2005 on Windows, and GCC 4.3 on Linux

EDIT2:

I have _msize under VC++2005
Unfortunately it results in an exception in debug mode….

EDIT3:

Well. I have tried the way I described above with the exception, and it works.
At least while I am debugging and ensuring that immediately after the call
to the library exits I run over the buffer boundaries. Works like a charm.

It just isn’t elegant and in no way usable in production code.

Answer 1

It’s not standard but if your library has a msize() function that will give you the size.

A common solution is to wrap malloc with your own function that logs each request along with the size and resulting memory range, in the release build you can switch back to the ‘real’ malloc.