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

size_t _msize(
   void *memblock 


Pointer to memory block.

Return Value

_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.


Routine Required header Compatibility
_msize <malloc.h> Win 98, Win Me, Win NT, Win 2000, Win XP

For additional compatibility information, see Compatibility in the Introduction.


All versions of the C run-time libraries.


See the example for realloc.

See Also

Memory Allocation Routines | calloc | _expand | malloc | realloc | Run-Time Routines and .NET Framework Equivalents