parent type must not be outside generic body

parent type must not be outside generic body

[Victor Porton]

1. What in ARM95 deprecated this?

2. What are methods of workaround of this where to
declare this type?

x.adb:3:24: parent type must not be outside generic body

x.ads:

generic
package X is

    type Base is tagged null record;

    procedure P;

end;

x.adb:

package body X is

   type Derived is new Base with null record;

   procedure P is
   begin
      null;
   end;

end X;

Re: parent type must not be outside generic body

[Eric G. Miller]

In <3dd6c668$0$301$bed64819@news.gradwell.net>, Victor Porton wrote:

> 1. What in ARM95 deprecated this?

Maybe...

                      3.9.1 Type Extensions 

   4
      A type extension shall not be declared in a generic body if the parent
      type is declared outside that body.

> 2. What are methods of workaround of this where to
> declare this type?

Maybe use a private section in the generic spec?

generic
package Foo_Generic is

   type Foo is tagged null record;
   
private

   type Bar is new Foo with null record;

end Foo_Generic;