How to get size of byte pointer?

Question

How to get the size of byte*.
I have byte* mData; this byte pointer is memory allocated and filled by a dll.
In the main application how to get the length or size of data occupied by the byte pointer.

Answer 1

Hello,
this is impossible. The function in the dll that fills the pointer must return the size of the data (amount of byte entries). Check the documentation of the function.
Regards, Guido
Edit: if it was a 0-terminated char array (char*), then you could check with strlen. Check the documentation of the filling function if the byte array (your byte* mData) has such a special End-byte too.

Answer 2

I think that it is possible in case of malloc, calloc, realloc. For example:

byte* mData = (byte*)malloc( 1000 );
. . .
size_t size = _msize( mData ); // result: 1000

(This probably needs /MD or /MDd options).

In case of HeapAlloc, you can use HeapSize.

Answer 3

It is not clear whether you are asking about the size of the data pointed to or the size of the pointer itself. If you need the size of the pointer itself then use the sizeof operator.