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From: Robert A Duff <bobduff@shell01.TheWorld.com>
Newsgroups: comp.lang.ada
Subject: Re: 'Protected' abstract subprograms
Date: Wed, 15 Jan 2014 16:21:57 -0500
Organization: The World Public Access UNIX, Brookline, MA
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Date: 2014-01-15T16:21:57-05:00
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adambeneschan@gmail.com writes:

> Or it could just mean that Ada didn't provide a complete enough way
> for generics to put conditions on the actual parameters.You can say
> "type T is private;", in which case the actual must be nonlimited; or
> you can say "type T is limited private;", in which case the actual may
> be limited or nonlimited.  But you don't have a way to say "the actual
> must be limited", which is what would be needed here.

Yes, that approach could work, but there are dozens of these "generic
private part" rules in the RM, and I suspect they all break privacy.

>...(And similarly
> for "tagged"; generics don't have a way to say "the actual must be
> untagged", and it seems that I submitted an AI in the last year or two
> about a case where using a tagged type as an actual for a generic
> formal private type led to a language hole involving derived types.)

- Bob