From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,98e3ee7e73b9dd89
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news4.google.com!news.glorb.com!newscon02.news.prodigy.com!newscon06.news.prodigy.com!prodigy.net!newsfeed-00.mathworks.com!nntp.TheWorld.com!not-for-mail
From: Robert A Duff <bobduff@shell01.TheWorld.com>
Newsgroups: comp.lang.ada
Subject: Re: Aliased
Date: 29 Jun 2005 17:10:15 -0400
Organization: The World Public Access UNIX, Brookline, MA
Message-ID: <wcc3br0c1jc.fsf@shell01.TheWorld.com>
References: <1118851601.345326.86640@g49g2000cwa.googlegroups.com>
 <PcOdnUT7y5Tjcy3fRVn-uw@comcast.com>
 <1118930589.514028.150340@g47g2000cwa.googlegroups.com>
NNTP-Posting-Host: shell01.theworld.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Trace: pcls4.std.com 1120079415 9254 192.74.137.71 (29 Jun 2005 21:10:15
 GMT)
X-Complaints-To: abuse@TheWorld.com
NNTP-Posting-Date: Wed, 29 Jun 2005 21:10:15 +0000 (UTC)
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2
Xref: g2news1.google.com comp.lang.ada:11741
Date: 2005-06-29T17:10:15-04:00
List-Id: <comp.lang.ada>

nblanpain@hotmail.com writes:

> So this is my sources and the compilation error :
>
> ------ Container.ads
> generic
>    type T_Item is private;
>    Static_Size : Integer;
> package Container is
>    type T_Array is array (Integer range <>) of T_Item;
>    type A_Array is access all T_Array;
>    type T_Container is tagged record
>       Obj_Array : aliased T_Array (1..Static_Size);
>       Ptr_Array : A_Array;
>    end record;
>    procedure Initialize (This : in out T_Container; Dynamic_Size : in
> Integer);
>    function P_Array (This : in T_Container) return A_Array;
> end Container;

I have a package that tries to do something similar.
Try wrapping the array in a record:

    type T_Rec(Length: Natural) is
        record
            A: T_Array(1..Length);
        end record;
    type T_Rec_Ptr is access all T_Rec;
    type T_Container is tagged record
        Obj_Array : aliased T_Rec (Length => Static_Size);
        Ptr_Array : T_Rec_Ptr;
    end record;

Then Initialize can set Ptr_Array to either "new T_Rec(Length =>
Dynamic_Size)" or "This.Obj_Array'Access".

Well, you'll want to change the names of things to make sense...
    
> ------ Container.adb
> package body Container is
>    procedure Initialize (This : in out T_Container; Dynamic_Size : in
> Integer) is
>    begin
>       if Dynamic_Size /= 0 then
>          This.Ptr_Array := new T_Array (1.. Dynamic_Size);
>      elsif Static_Size /= 0 then
>         This.Ptr_Array := This.Obj_Array'Access; --- Compilation Error
>      end if;
>    end Initialize;
>    function P_Array (This : in T_Container) return A_Array is
>    begin
>       return This.Ptr_Array;
>    end P_Array;
> end Container;
> 
> -- Compilation Error : Object subtype must statically match designated
> subtype. No local pointer cannot point to local object.

- Bob