Therefore, to save memory, how about not allowing holes in filebuf?
i.e., filebuf will be filled with count contiguous items of type
"filebuf_type". filebuf_type has the same type signature as etype.
The basic datatypes within filebuf_type are located contiguously, i.e.
the ith basic datatype in filebuf_type is located at
disp(i) = disp(i-1) + file_extent(i-1).
Rajeev