Re: 'address on a subprogram parameter

["J-P. Rosen" <rosen@adalog.fr>]

Le 20/04/2021 à 17:10, Vincent Marciante a écrit :
> I think that I used to know this but currently am not sure:
> 
> Assuming the a value is passed by reference, is 'Address of a parameter
> always the address of the object that is passed as in:
> 
> ...
> 
>    type Big_Record is ...
> 
>    Object : Big_Record;
> 
>    procedure Proc (Param :  in out Big_Record) is
>    begin
>      if  Param'Address /= Object'Address  then
>           raise Constraint_Error;
>      end if;
>    end;
> 
> begin
>    Proc(Object);
>    ...
> 
As usual, the real question is "why do you need that?"

If you want to check whether a parameter IS a certain variable, use 
Param'Has_Same_Storage(Object). If you want to check whether variables 
have a part in common, use Param'Overlaps_Storage (Object).
See 13.3 (73.1/3 .. 73.10/3)


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J-P. Rosen
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