Re: Ada 2012 : aliased parameters ?

[Maciej Sobczak <see.my.homepage@gmail.com>]

On 29 Mar, 05:16, "Randy Brukardt" <ra...@rrsoftware.com> wrote:

> The motivating case is to make the containers better. Ada 2012 adds the
> following to all of the containers:
>
>     function Reference (Container : aliased in out Vector; Position : in
> Cursor)
>        return Reference_Type;

Out of curiosity - is it possible to leak the reference this way? I
mean - is it possible for the caller to make a copy of returned
reference and store it arbitrarily long?

Note that the "copy" might not be obvious, as in:

declare
   My_Element : Vector_Type.Reference_Type renames
     My_Vector.Reference (My_Cursor);
begin
   My_Element.Comp := 10;
   My_Element.Other_Comp := 3.14;
end;

The C++ equivalent of this is both a fantastic performance feature and
a deadly security hole. How is this solved in Ada?

--
Maciej Sobczak * http://www.msobczak.com * http://www.inspirel.com