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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: class wide iterable (and indexable)
Date: Wed, 23 Jan 2019 16:47:41 -0600
Organization: JSA Research & Innovation
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Xref: reader01.eternal-september.org comp.lang.ada:55347
Date: 2019-01-23T16:47:41-06:00
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"Shark8" <onewingedshark@gmail.com> wrote in message 
news:9eedf818-8bfb-465b-afe5-aa3fb0525948@googlegroups.com...
> Wouldn't this be a non-issue if we could Static_Predicate Array-types like 
> so?
>
> Type Some_String is Array(Positive range <>) of Character
>  with Static-Predicate => Some_String'First = 1;

The idea of a static predicate is for them to stand-in for proper set 
constraints (I would have preferred the latter, but I was alone on that), so 
they don't have anything to do with array bounds.

You can do this with Dynamic_Predicates, but it doesn't make the slices act 
differently, so problems will ensue. Changing the semantics of slices 
(essentially to force sliding everywhere) would require some sort of 
declaration beyond just the predicate.

                      Randy.