From: Steve Jones - JON <jon@hpodid2.eurocontrol.fr>
Subject: Re: p(x: out File_Type)
Date: 1996/12/03
Date: 1996-12-03T00:00:00+00:00 [thread overview]
Message-ID: <2su3q396xi.fsf@hpodid2.eurocontrol.fr> (raw)
In-Reply-To: 57u5ik$qdc$1@goanna.cs.rmit.edu.au
ok@goanna.cs.rmit.edu.au (Richard A. O'Keefe) writes:
>
> Does
>
> procedure P(...; X: out File_Type)
>
> ever make sense, where File_Type is one of the standard file types
> (from Sequential_IO, Direct_IO, or Text_IO)?
First place when this would be used is when it conflicts with
a company standards, some detail that functions should be non
destructive operators only. So you could have a standard function like
procedure Initialise_Recording(Recording_Number : in INTEGER;
Workstation_Number : in NATURAL;
Recording_File : out File_Type);
(The actual names and types of the paramaters have been change to
protect the innocent).
I have seen single out parameters on other occasions, normally to
keep a standard interface (ie 15 procedures doing similar things
all implemented as procedures but 6 have an out parameter).
But the first reason is the one I see most often, to be fair to it
as a rule in standards it seemed to work fairly well on the last
project I was on as it made it clearer where people were doing the
actual work and what was information serving.
[snip]
prev parent reply other threads:[~1996-12-03 0:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-12-02 0:00 p(x: out File_Type) Richard A. O'Keefe
1996-12-03 0:00 ` Steve Jones - JON [this message]
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