Finally there is another question remaining:
Are objects always packed ?
If not then it could be a problem.
Something which records do allow.
Bye,
Skybuck.
----- Original Message -----
From: "Daniël Mantione" <[EMAIL PROTECTED]>
To: "FPC-Pascal users discussions" <fpc-pascal@lists.freepascal.org>
Sent: Saturday, February 16, 2008 5:24 PM
Subject: Re: [fpc-pascal] Empty record inside another record ?
Op Fri, 15 Feb 2008, schreef Skybuck Flying:
To me it seems like some kind of trick, to extend a record at runtime.
The empty record field, functions as a sort of offset/label/pointer if you
will to the new fields that will will be extended to the record by simply
allocating more memory then the size of the record.
Then this "label"/"field" can be used as a sort of offset, by typecasting
it
to some extension record type.
Could be pretty handy, quite impressive trick.
However, is it safe to use ?
Empty records are valid Pascal.
I cannot find anything in the documentation about this ?
Nothing in the documentation says it is forbidden either. The reason
it is not explicetely mentioned is because there exists a
much better method, objects:
type base_structure=object
field1:byte;
end;
extended_structure=object(base_structure)
field2:byte;
end;
Daniël
--------------------------------------------------------------------------------
_______________________________________________
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal
_______________________________________________
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal
