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Newsgroups: comp.lang.ada
Date: Fri, 1 Jul 2016 06:49:18 -0700 (PDT)
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Subject: Re: Generic Embedded List Nodes
From: Warren <ve3wwg@gmail.com>
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Xref: news.eternal-september.org comp.lang.ada:30994
Date: 2016-07-01T06:49:18-07:00
List-Id: <comp.lang.ada>

On Saturday, 25 June 2016 01:50:41 UTC-4, Niklas Holsti  wrote:
> On 16-06-24 15:49 , Warren wrote:
..
>     procedure Insert_At_Head (
>        List : access List_T;
>        Node : in     Emb_Node_Ref_T)
>     is
>     begin
>        if List.Next /= null then
>           List.Next.Prev := Node;
>        end if;
>        Node.Next := List.Next;
>        List.Next := Node;
>        Node.Prev := Emb_Node_Ref_T (List);
>     end Insert_At_Head;

Niklas: I finally got a few minutes to revisit this and worked up a full example based upon yours.  I fear that the design is still flawed. I'm using a slightly modified version of this, but basically, the problem occurs at the line:

>        Node.Prev := Emb_Node_Ref_T (List);

with the exception:

raised PROGRAM_ERROR : niklas.adb:14 accessibility check failed

My example code is located on github here:  https://github.com/ve3wwg/ada_embedded_list

Maybe there is pilot error somewhere. I'm using: GNATMAKE 6.1.0.

Warren