Re: Choice of variant record discriminant (design question)

[christoph.grein@eurocopter.com]

Jacob Sparre Andersen wrote:
> I have declared a record type like this:
>
>    type Preprocessed_Parameters (Measurement_Count : Natural := 0) is
>       record
>          case Measurement_Count is
>             when 0 =>
>                null;
>             when others =>
>                Mean_Value      : Scalar;
>                Scaled_Variance : Scalar;
>          end case;
>       end record;
>
> I would like to return an object of that type from a function using
> this piece of code:
>
declare
  Parm: Preprocessed_Parameters (Measurement_Count => Count);
begin
>    if Count = 0 then
       null;
>    else
>       [...]
       Parm.Mean_Value := Mean;
       Parm.Scaled_Variance := Sum;
       return Parm;
>    end if;
> 
> I can't do this, since the discriminant has to be static.