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From: Matthew Heaney <mheaney@on2.com>
Newsgroups: comp.lang.ada
Subject: Re: Declaration of private type Containers
Date: Fri, 30 May 2008 13:27:49 -0700 (PDT)
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Date: 2008-05-30T13:27:49-07:00
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On May 30, 7:49=A0am, alexander.kle...@web.de wrote:
> The only thing I want to do is to =A0declare a list package, whose
> Element_Type is of a private record type:
>
> package A is
>
> type My_Type is private
>
> package My_Type_Lists is new Ada.Containers.Doubly_Linked_List
> =A0 =A0 =A0(Element_Type =A0 =A0 =A0=3D> My_Type);
>
> private
>
> type My_Type is
> record
> ...
> end record;
>
> end A;

It's unlikely you need all of the features supported by the standard
linked list container.  If so, one alternative for you would be to
create a more high level container:

package A is
  type T is private;

  type Container is tagged limited private;

  procedure Insert
   (C : in out Container;
    Obj : T);

  procedure Remove
    (C : in out Container;
     Obj : T);

  procedure Iterate
    (C : Container;
     P : not null access procedure (Obj : T));

private
   type T is ...;

   package T_Lists is new Ada.C.DLLists (T);

   type Container is tagged limited record
     L : T_Lists.List;
   end Container;

end A;