Re: Type extension and discriminants

[AdaMagica <christ-usch.grein@t-online.de>]

On Saturday, October 11, 2014 7:45:56 PM UTC+2, sbelm...@gmail.com wrote:
> package A is
>    type T1 (<>) is tagged limited private;
>    function T1_Ctor return T1;
> private
>    type T1 (I_Ptr : access Integer) is tagged limited null record;
> end A;
> 
> package body A is
>    function T1_Ctor return T1 is
>    begin
>       return (I_Ptr => null);
>    end T1_Ctor;
> end A;
> 
> with A;
> package B is
>    type T2 (<>) is new A.T1 with private;

I guess the following function is implicitly declared here and must be overridden because it's abstract:
     function T1_Ctor return T2;

>    function T2_Ctor return T2;
> private
>   type T2 is new A.T1 with null record;
> end B;
>
> package body B is
>    function T2_Ctor return T2 is
>    begin
>       return T2'(A.T1_Ctor with null record);
>    end T2_Ctor;
> end B;