Return the number of bytes of the most recent deallocation request. Return 0 if a null pointer was most recently deallocated, or if the request was invalid (e.g., an attempt to deallocate memory not allocated through this allocator).
Declared in <bslma_testallocator.h>
<bslma_testallocator.h>
Allocator::size_type lastDeallocatedNumBytes() const;