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From: dmurdoch@watstat.waterloo.edu (Duncan Murdoch)
Newsgroups: comp.lang.pascal
Subject: Re: DISPOSE'ing
Message-ID: <1991Jun29.163728.16026@maytag.waterloo.edu>
Date: 29 Jun 91 16:37:28 GMT
References: <1144.286c2900@vger.nsu.edu>
Sender: news@maytag.waterloo.edu (News Owner)
Organization: University of Waterloo
Lines: 28

In article <1144.286c2900@vger.nsu.edu> g_harrison@vger.nsu.edu (George C. Harrison, Norfolk State University) writes:
>A student has been crying the blues because he code works on
>Turbo Pascal and not on VAX Pascal.  It is totally ISO standard.
>His program contains code similar to
>
>program TEST;
>type  PTR = ^NODE;
>      NODE = record
>              DATA : INTEGER;
>              NEXT : PTR
>             end;
>var
>      P, TEMP : PTR;
>begin
>      new(P);
>      TEMP := P;
>      DISPOSE(P);
>      DISPOSE(TEMP)
>end.
>
>Apparently TP (of which I am NOT an expert) allows for a program to 
>dispose of the nodes pointed to by P and TEMP even though the nodes 
>are at exactly the same location.  

Is that really allowed by the standard?  TP version 6 catches it as a run-time 
error 204, invalid pointer operation.

Duncan Murdoch