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From: Simon Wright <simon.j.wright@mac.com>
Newsgroups: comp.lang.ada
Subject: Re: Loosing tagged type via linked list
Date: Sat, 09 Feb 2008 11:40:35 +0000
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Date: 2008-02-09T11:40:35+00:00
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Georg Bauhaus <see.reply.to@maps.futureapps.de> writes:

> jason.height@gmail.com wrote:

>> I am attempting this in Ada95, with my own Linked_List container impl,
>> which seems to be destroying the type information. If anyone knows a
>> Ada95 list implementation that can store items of different types
>> (derived from a base type) then please let me know.
>
> The Booch components will let you do this, using indefinite
> generic formal types.
> http://sourceforge.net/project/showfiles.php?group_id=135616.

If you want to use a definite formal type, then access-to-classwide is
what you need (there will have to be an access under the hood,
whatever solution you adopt).

  type A_Type_P is access A_Type'Class;

Allocation and, more challengingly perhaps, deallocation are then up
to you.

> (The WiKi seems out of order at this time; doc is contained in
> an accompanying archive.)

So it is. First time I've heard! Can't be visited very often ...