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From: favierp@sofreavia.fr (Pierre Favier)
Newsgroups: comp.lang.ada
Subject: Re: How to test object hierarchy
Date: 18 Dec 2003 23:45:44 -0800
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Stephen Leake <stephen_leake@acm.org> wrote in message news:<mailman.138.1071792945.31149.comp.lang.ada@ada-france.org>...
> favierp@sofreavia.fr (Pierre Favier) writes:
> 
> > I am wondering how to test for two objects which types both derive from a
> > common root type if one of them derives from the other. 
> 
> Interesting. Here's one way:
> 
> ......
>
> It does seem like you aught to be able to do this without string operations.

Yes. I had thought of using tag's Expanded_Name like you suggested but was
wondering whether there was a language feature that I was overlooking.

If you look at spec of package Ada.Tags in GNAT you see the following
function in the private part of the spec:

   function CW_Membership (Obj_Tag : Tag; Typ_Tag : Tag) return Boolean;
   --  Given the tag of an object and the tag associated to a type, return
   --  true if Obj is in Typ'Class.

which could be used as is for two object tags instead of an object tag and
a type tag. 

Why not make it public? Is any addition of this sort planned for Ada 200X?