Path: utzoo!attcan!uunet!snorkelwacker!bloom-beacon!eru!luth!sunic!kth.se!news
From: d88-eli@draken.nada.kth.se (Erik Liljencrantz)
Newsgroups: comp.lang.pascal
Subject: Re: (one way to) Copying objects in Turbo Pascal 5.5
Message-ID: <1990May28.150855.6710@kth.se>
Date: 28 May 90 15:08:55 GMT
References: <4878@plains.UUCP> <1990May25.132722.29073@maytag.waterloo.edu>
Reply-To: d88-eli@nada.kth.se (Erik Liljencrantz)
Organization: Royal Institute of Technology, Stockholm, Sweden
Lines: 18

In article <1990May25.132722.29073@maytag.waterloo.edu> dmurdoch@watstat.uwaterloo.ca (Duncan Murdoch) writes:
>In article <4878@plains.UUCP> gus@plains.UUCP (jim gustafson) writes:
>>>I'd like to have a constructor for an object that just copies another instance
>>>of it or one of its descendants, and (the hard part) also copies the type
>>>information.  
...
>(Since they're descendants, they may contain lots of other stuff too.)
...
>Duncan Murdoch

I believe the SizeOf operator knows how to compute the size of a descendant
(the VMT described in the OOPS-manual contains a special size-field for this
purpose). If "the lot's of other stuff" in the descendant doesn't contain
any pointers which contents also should be duplicated SizeOf should be
sufficient to copy the contents (my favorite: Move, fast but dangerous!).
---
Erik Liljencrantz     | "No silly quotes!!"
d88-eli@nada.kth.se   |  Embraquel D. Tuta