val memory_size : t -> intmemory_size t returns how many word(s) is needed to store t.
make ?copy raw returns a Rabin's fingerprint of raw. ?copy signals to copy the input buffer raw or not because make expects to take the ownership of raw.
So, if the user want to change (by side-effect) raw then, returned value by make is not valid anymore. However, if copy is true, make will allocate a new Cstruct.t and copy raw to this new Cstruct.t.