function GetAllocMemSize: Integer;
{$IF CompilerVersion >= 18}
var
  I: Integer;
  MemMgrState: TMemoryManagerState;
{$IFEND}
begin
{$IF CompilerVersion < 18}
  Result := AllocMemSize;
{$ELSE}
  GetMemoryManagerState(MemMgrState);
  Result := MemMgrState.TotalAllocatedMediumBlockSize +
    MemMgrState.TotalAllocatedLargeBlockSize;
  for I := 0 to High(MemMgrState.SmallBlockTypeStates) do
    Result := Result + MemMgrState.SmallBlockTypeStates[I].InternalBlockSize +
      MemMgrState.SmallBlockTypeStates[I].UseableBlockSize;
{$IFEND}
end;