Re: Ada.Containers.Doubly_Linked_Lists

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Niklas Holsti <niklas.holsti@nospam.please> writes:

> Carroll, Andrew wrote:
>> Ahhhhh, I see.
>
> (Please quote a bit of the post to which you are replying so that the
> context of your "Ahhhhh" is clearer :-)
>
>> Okay, so, just out of curiosity, what do I do if I need the
>> Node_type within Ada.Containers.Doubly_Linked_Lists to
>> have an additional "attribute"?
>
> What Node_Type? Are you peeking at the *private* part of
> Ada.Containers.Doubly_Linked_Lists, or even at the source-code of the
> body of the generic? That's useless because you can't access the
> private stuff or the stuff in the body.
>
> Whatever you want to keep in your list, put it in your Element_Type,
> the type that you use to instantiate Doubly_Linked_Lists. For example,
> make it a record type and put in whatever components you need.

And, if Niklas' answer was unclear, do not add Prev or Next to your
Element_Type; it is the generic linked list's job to add and manage
them.  If all you want is an unbounded string, just say

package Lists_Of_Unbouned_Strings is
   new Ada.Containers.Doubly_Linked_Lists
     (Element_Type => Ada.Strings.Unbounded.Unbounded_Strings);

L : Lists_Of_Unbouned_Strings.List;

and off you go.

-- 
Ludovic Brenta.