Returns the size of a memory block allocated in the heap.

size_t _msize(
   void *memblock
);

memblock
Pointer to the memory block.

_msize returns the size (in bytes) as an unsigned integer.

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.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

For more compatibility information, see Compatibility.

All versions of the C run-time libraries.

See the example for realloc.

Memory allocation
calloc
_expand
malloc
realloc