Re: "NULL" returned by a function

[Shark8 <OneWingedShark@gmail.com>]

On 08-Aug-14 15:10, Victor Porton wrote:
> What if I want to make a function which returns either a value of type T or
> a value signifying "nothing" (like null pointer)?

What's wrong with discriminated records?

Type Some_Container( Empty : Boolean ) is
   case Empty is
    When True  => Null;
    When False => Item : T;
   end case;
end record;

> To make things worse, T is a controlled type, so if we return just "access
> T" the finalization of the object of type T may be easily overlooked.

It seems that you're trying to program C/C++ in Ada, don't, that way 
lies only pain.