let make length default_value =
if length < 0
then raise (Invalid_argument "Bitarray.make");
let virtual_length = length / size + if length mod size != 0 then 1 else 0 in
let array = Array1.create int16_unsigned c_layout virtual_length in
for i = 0 to virtual_length - 1 do
array.{i} <- if default_value then 65535 else 0;
done;
{
array = array;
length = length
}