Newbie Question - memory overlays

[Jacques Collin]

I union would not fit the job.

In Delphi, I can have, for example,
--  fdata1    :  file of infonode
--  datastore : array[1..n] of infonode;
--  ctrlpoint : array[1..100] of infonode absolute datastore[1]
where
the first 100 "infonodes" can be used as an array. And the rest of
the "datastore" can be used as a list or even a tree.

at some point the "datstore" will be written out to disk.
I would prefer to avoid a cumbersome work-around like a union
(a.k.a variant records) in favour of the elegant Delphi solution
of simply using the "absolute" attribute.

Any suggestions?

Thanks