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From: "J-P. Rosen" <rosen@adalog.fr>
Newsgroups: comp.lang.ada
Subject: Re: Subtypes and type invariants in Ada2012
Date: Mon, 21 Aug 2017 18:10:13 +0200
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Date: 2017-08-21T18:10:13+02:00
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Le 21/08/2017 à 17:38, Victor Porton a écrit :
> I thought that type invariants are designed for subtypes. I mistook!
> [...] 
> So, my question: Is it possible to restrict a subtype with something like a 
> type invariant?
> 
> I want a subtype restricted by an arbitrary condition. Is it possible?
> 

This is rather a subtype predicate.

Type invariants are here to publicize properties of a private type,
otherwise the user knows nothing about it (since it is private!)
-- 
J-P. Rosen
Adalog
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