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Newsgroups: comp.lang.ada
Date: Mon, 27 Jul 2020 00:47:30 -0700 (PDT)
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Subject: Re: Proposal: Auto-allocation of Indefinite Objects
From: Yannick Moy <moy@adacore.com>
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Xref: reader01.eternal-september.org comp.lang.ada:59538
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Hi Stephen,

On Saturday, April 4, 2020 at 12:48:43 AM UTC+2, Stephen Davies wrote:
> Firstly, apologies if this has already been discussed or,=20
> more likely, if it's a really stupid idea for some reason=20
> that I haven't thought of.=20

Actually, that's something more and more of us would like to see.

> My proposal is that it should (sometimes?) be possible to declare=20
> objects of indefinite types such as String and have the compiler=20
> automatically declare the space for them without the programmer=20
> having to resort to access types.=20

I agree with the goal.

> Benefits:=20
>=20
> 1. Easier, especially for newbies/students.=20
> 2. Safer due to reduced use of access types.=20
> 3. Remove the need to have definite and indefinite versions of generic un=
its.=20

I agree with 2 only if we can combine this with safe handling of aliasing. =
It would be terrible to have such a feature lead to unsafe code if you some=
how copy the pointer. Also, for strings that's possibly not the only change=
 needed. What you'd like really is to be able to reassign the string to som=
e larger/smaller string, like you do when using Unbounded_String.

On 2020-04-04, Jeffrey R. Carter wrote:
>
> the ARG is aware of them and has chosen to take no action.
> That seems unlikely to change.

On the other hand, AdaCore has launched a project to collect/discuss ideas/=
suggestions/problems regarding the evolution of Ada and SPARK: https://gith=
ub.com/AdaCore/ada-spark-rfcs
Feel free to open an Issue there on that topic.