From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.5-pre1 (2020-06-20) on
	ip-172-31-74-118.ec2.internal
X-Spam-Level: 
X-Spam-Status: No, score=0.0 required=3.0 tests=BAYES_20,FREEMAIL_FROM
	autolearn=ham autolearn_force=no version=3.4.5-pre1
X-Received: by 2002:a37:a395:: with SMTP id m143mr19967512qke.439.1613988886203;
        Mon, 22 Feb 2021 02:14:46 -0800 (PST)
X-Received: by 2002:a25:6e57:: with SMTP id j84mr33489233ybc.277.1613988886036;
 Mon, 22 Feb 2021 02:14:46 -0800 (PST)
Path: eternal-september.org!reader02.eternal-september.org!news.mixmin.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: comp.lang.ada
Date: Mon, 22 Feb 2021 02:14:45 -0800 (PST)
In-Reply-To: <s0vj5f$u8s$1@dont-email.me>
Injection-Info: google-groups.googlegroups.com; posting-host=94.31.102.170; posting-account=rmHyLAoAAADSQmMWJF0a_815Fdd96RDf
NNTP-Posting-Host: 94.31.102.170
References: <4086f350-c56b-4eec-91d3-ef685230b011n@googlegroups.com> <s0vj5f$u8s$1@dont-email.me>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <67ea71d9-489a-4802-9cf0-d955f6ecce62n@googlegroups.com>
Subject: Re: "unconstrained subtype in component declaration" vs "discriminant
 in constraint must appear alone"
From: AdaMagica <christ-usch.grein@t-online.de>
Injection-Date: Mon, 22 Feb 2021 10:14:46 +0000
Content-Type: text/plain; charset="UTF-8"
Xref: reader02.eternal-september.org comp.lang.ada:61408
List-Id: <comp.lang.ada>

J-P. Rosen schrieb am Montag, 22. Februar 2021 um 07:32:27 UTC+1:
> 3) Sets_of_Card (0..nb-1) 
>Yes, you cannot make computations 
> in a discriminant constraint. Although this may seem sometimes 
> frustrating to the user, it was required for implementation reasons. 

Remeber, a discriminant is a record component like the others, so it covers some bits.
If it were allowed to be used in expressions, either each result would need a storage place of its own or a reevaluation at every use of the object.