Portability questions (Arrays)_(re)

Mon, 2 Jun 1997 14:21:19 +0200

Peter Gerwinski wrote:

> > function f(var a:t):integer;
> > var
> >   p:^integer;
> > begin
> >   p:=@a[0];
> >   {some loop}
> >     if {...} then
> >       begin
> >         p^:=...;
> >         inc(p) {is this ok, BTW?}
> >       end;
> >   {...}
> >   f:="offset of p in a"
> > end.
>
> "inc(p)" should work in GPC.  You can even do
>
>     for p:= @a [ 0 ] to @a [ n ] do
>       p^:= ...;

The latter doesn't fit into the procedure above, but if "inc(p)" works, fine!

> What about intoducing a "difference between pointers" operator which returns
> the number of elements they lie apart (as an integer)?
>
>     f:= p - @a [ 0 ];

This would be great!

> (Only with (*$X+*), of course.)

Of course!
-- 
Frank Heckenbach, Erlangen, Germany
heckenb@mi.uni-erlangen.de
Turbo Pascal:   http://www.mi.uni-erlangen.de/~heckenb/programs.htm
Internet links: http://www.mi.uni-erlangen.de/~heckenb/links.htm

Frank Heckenbach (heckenb@mi.uni-erlangen.de)