Re: 'Read for pointers

["Pat Rogers" <progers@NOclasswideSPAM.com>]

<tmoran@bix.com> wrote in message
news:YEJf5.49$LV1.69164@news.pacbell.net...
> >Further to my previous post, to the effect that one can indeed read
> >mode out parameters: the access value of the actual is copied into
the
> >formal, so you get a meaningful value coming in even though the
mode
> >is out. See RM 6.4.1{12,13}
> So to catch bugs at an early time, given
>     type Handle_Type is access ...
>     procedure p(x : some_stuff;  Handle : out Handle_Type);
> one should
>     Handle := null;
>     p(y, Handle);
> otherwise a supposedly new object at Handle.all may actually be
> an old object.  That must be fun to debug.

I'm not sure I see your point, given the context.  The variable
Handle, used as the actual to the call to P, would initially have the
null value (absent any explicit initialization) automatically.  So the
value copied in is still meaningful, even if never assigned prior to
the call.

--
Pat Rogers                            Consulting and Training in:
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Adam ... does not deserve all the credit; much is due to Eve, the
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Mark Twain