function StrAllocW(Size: Cardinal): PWideChar;
begin
  Size := SizeOf(Cardinal) + (Size * SizeOf(WideChar));
  GetMem(Result, Size);
  PCardinal(Result)^ := Size;
  Inc(PAnsiChar(Result), SizeOf(Cardinal));
end;

procedure StrDisposeW(Str: PWideChar);
begin
  if Str <> nil then
  begin
    Dec(PAnsiChar(Str), SizeOf(Cardinal));
    FreeMem(Str, Cardinal(Pointer(Str)^));
  end;
end;