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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: A few questions
Date: Tue, 03 Nov 2015 08:26:45 +0000
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Date: 2015-11-03T08:26:45+00:00
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"Randy Brukardt" <randy@rrsoftware.com> writes:

> "Simon Wright" <simon@pushface.org> wrote in message 

>>   function Constant_Reference
>>     (Container : aliased Date_Container;
>>      Position  : Cursor) return Constant_Reference_Type;
>>
>> returning
>>
>>   type Constant_Reference_Type
>>      (Element : not null access constant Ada.Calendar.Time) is private
>>   with
>>      Implicit_Dereference => Element;

> If you *only* need constants, the Constant_Indexing function can be a
> normal function (no implicit dereference required). In that case, the
> implementation will do the memory management. Note the difference in
> wording between 4.1.6(2/3) and 4.1.6(3/3) (there is no requirement on
> the return type for Constant_Indexing).

Worked a treat!

> OTOH, I think GNAT got that wrong somehow when I constructed an ACATS
> test to try that (don't recall the details). So it may not work in
> your copy of GNAT, most likely it will in a future version.

No problem (for the constant case) with GCC 5.1.0 or GNAT GPL 2015.