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_______________________________________________
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