From: Jacob Sparre Andersen <jacob@jacob-sparre.dk>
Subject: Re: Generic private type declaration
Date: Sat, 26 Nov 2016 09:45:32 +0100
Date: 2016-11-26T09:45:32+01:00 [thread overview]
Message-ID: <877f7qy6hf.fsf@adaheads.sparre-andersen.dk> (raw)
In-Reply-To: o19sod$ug2$1@dont-email.me
Alejandro R. Mosteo wrote:
> I need some eyes on this error because I'm missing something
> basic. When compiling this code:
>
> procedure B001_Tagged is
>
> generic
> type X is private;
> package Untagged is
>
> type Y is new X;
>
> end Untagged;
>
> package Ok is new Untagged (Integer);
>
> type Void is tagged null record;
>
> package Err is new Untagged (Void); -- Error here
>
> begin
> null;
> end B001_Tagged;
>
> I get in both gnat 4.9.3 and gpl2016 the following error:
>
> b001_tagged.adb:15:04: instantiation error at line 7
> b001_tagged.adb:15:04: type derived from tagged type must have extension
> gnatmake: "b001_tagged.adb" compilation error
>
> I would expect that the view inside the generic package is untagged
> and so the type renaming in line 7 should be correct?
I agree with your expectation.
I suspect that this is an error due to how GNAT expands generics. It
might be useful to try to see how Janus/Ada and ICC/Ada treats it. If I
remember correctly, Janus/Ada implements generics differently from GNAT.
Greetings,
Jacob
--
"... but I don't think even Tucker can do scheduling with no cost."
-- Randy Brukardt
next prev parent reply other threads:[~2016-11-26 8:45 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-25 17:36 Generic private type declaration Alejandro R. Mosteo
2016-11-25 19:17 ` Dmitry A. Kazakov
2016-11-28 14:54 ` Alejandro R. Mosteo
2016-11-25 19:18 ` AdaMagica
2016-11-28 14:57 ` Alejandro R. Mosteo
2016-11-25 19:38 ` G.B.
2016-11-26 8:45 ` Jacob Sparre Andersen [this message]
2016-11-26 19:18 ` Tero Koskinen
2016-11-28 15:05 ` Alejandro R. Mosteo
2016-11-28 21:32 ` Randy Brukardt
2016-11-29 11:12 ` Alejandro R. Mosteo
2016-11-29 11:42 ` Dmitry A. Kazakov
2016-11-29 23:48 ` Randy Brukardt
2016-11-28 23:25 ` Robert Eachus
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