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From: Niklas Holsti <niklas.holsti@tidorum.invalid>
Newsgroups: comp.lang.ada
Subject: Re: Ada 2012: In-out parameters for functions
Date: Sun, 05 May 2013 23:37:10 +0300
Organization: Tidorum Ltd
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Date: 2013-05-05T23:37:10+03:00
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On 13-05-05 22:23 , Yannick Duchêne (Hibou57) wrote:
> Le Sun, 05 May 2013 17:09:11 +0200, Niklas Holsti
> <niklas.holsti@tidorum.invalid> a écrit:
>> I believe I have made some Ada coding errors that would have been
>> revealed by mode notations in calls. I don't remember the exact
>> examples, but I think one concerned a procedure in which an "in"
>> parameter was changed to an "in out" parameter, because some new uses of
>> the subprogram required it -- but then some old uses no longer worked,
>> because they assumed that the actual for this parameter would not be
>> changed. And the actual was a non-constant object, so the compiler saw
>> nothing wrong in its use for an in-out parameter.
> 
> That's an argument for Randy's idea to make constant the default mode
> for local variable and constant declarations.

Perhaps... as I remember, this object (the actual parameter in the
example I remember) was an array, or a record, which was built up by
several assignment statements, so it could not be a constant, without
considerable changes to the code.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
      .      @       .