Re: List container strawman

[Ted Dennison<dennison@telepath.com>]

In article <9s6a60$a49$1@nh.pace.co.uk>, Marin David Condic says...
>generic
>    type Something is private ;
>package A_Package is
>    type Something_Else is private ;
>private
>    type Something_Else is record
>        X : Some_Type_Derived_From_Controlled_Along_Some_With_Chain ;
>    end record ;
>end A_Package ;
>
>Without having passed anything like this past a compiler, I just don't know
>if it is legal and gets Ted the ability to instantiate the generic from
>within a non-library-level scope.

The problem with this approach is that the X field in Something_Else can have no
knowledge of any of other the fields in Something_Else, and thus is unable to
control it. It can control itself, but not its parent Something_Else. 

I think you can sometimes use tricks like this if the thing being controlled has
nothing to do with any of the generic parameters (or anything dependant upon
them). But in all other cases you are hosed, as near as I can tell.

---
T.E.D.    homepage   - http://www.telepath.com/dennison/Ted/TED.html

No trees were killed in the sending of this message. 
However a large number of electrons were terribly inconvenienced.