_msize

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

Syntax

size_t _msize(
   void *memblock
);

Parameters

memblock
Pointer to the memory block.

Return value

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

Remarks

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 (18,446,744,073,709,551,615 unsigned).

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

Requirements

For more compatibility information, see Compatibility.

Libraries

All versions of the C run-time libraries.

Example

See the example for realloc.

See also

Memory allocation
calloc
_expand
malloc
realloc