Returns the size of a memory block allocated in the heap.
The _msize function returns the size, in bytes, of the memory block allocated by a call to calloc, malloc, or realloc.
When the application is linked with a debug version of the C run-time libraries, _msize resolves to _msize_dbg. For more information about how the heap is managed during the debugging process, see The CRT Debug Heap.
This function validates its parameter. If memblock is a null pointer, _msize invokes an invalid parameter handler, as described in Parameter Validation. If the error is handled, the function sets errno to EINVAL and returns -1.
Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.