Re: Problem with generic parameter

[Marius Amado Alves <amado.alves@netcabo.pt>]

I, Marius Amado Alves, just wrote:

> I think this is legal, so the compiler is buggy. But I find it an 
> unlogical generic idiom, and probably the bug has passed unnoticed 
> before for this reason. That is, nobody wrote this before. What I find 
> unlogical is the Generic_Root.Child parameters. I would find it 
> logical to represent the array type as an exported entity instead of a 
> generic parameter.
>
> generic
>    type Indices is (<>);
> package Generic_Root
>    type Measurement is array (Indices) of Measurement;

Here's the complete 'logical' idiom, which also corrects faults above:

generic
    type Indices is (<>);
package Generic_Root.Child_By_Marius is
    type Measurement_Array is
       array (Indices range <>) of Measurement;
end;

with Generic_Root;
with Generic_Root.Child_By_Marius;
procedure Marius_Demo is
    type Scalar is digits 15;
    package Measurements is
       new Generic_Root (Scalar => Scalar);
    package Measurements_Text_IO is
       new Measurements.Child_By_Marius
         (Indices => Positive);
    -- now here you have your unconstrained array type
    -- it is Measurements_Text_IO.Measurement_Array
    -- and you have defined it only once
    -- and the whole thing compiles
begin
    null;
end;