Re: Ada 2005,Doubly_Linked_List with Controlled parameter

[George J <ivanov_george@list.ru>]

вторник, 5 апреля 2016 г., 11:50:31 UTC+3 пользователь Dmitry A. Kazakov написал:
> On 05/04/2016 10:35, George J wrote:
> > ....
> >> Or, better, since you never change Name or Surname:
> >>
> >>      type Info_Record
> >>         (Name_Length : Positive; Surname_Length : Positive) is
> >>      record
> >>         Name    : String (1..Name_Length);
> >>         Surname : String (1..Surname_Length);
> >>         Age     : Natural;
> >>      end Info_Record;
> >>
> >> --
> >> Regards,
> >> Dmitry A. Kazakov
> >> http://www.dmitry-kazakov.de
> >
> > I do it this way, and I have to change Doubly_Linked_List(Info_Record) to
> > Indefinite_DoublY_Linked(Info_Record) cause of error:"unconstrained
> > subtype in component declaration". Am I right?
> 
> I am not familiar with the design of standard container's doubly-linked 
> lists. Normally, a list always deals with limited indefinite elements. 
> Otherwise, it does not make much sense.
> 
> > Or may be it's any way to
> > use Doubly_Linked_List? And,BTW, I'm afraid of using Indefinite List
> > cause I think,that it can request much more memory, than
> > Doubly_C_L,isn't it?
> 
> As I said, I don't know how it is designed. There are many ways to 
> design a list. One is that elements are derived from linked base 
> elements. Another is that links are allocated outside and point to the 
> elements. A better variant of the latter is to use a custom storage pool 
> and put links before the elements. In all three methods there is no 
> overhead of having elements limited indefinite.
> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de

It seems I've got.Thanks!