Re: Ada 9X: Eliminating the re-emergence of predefined operations

[cis.ohio-state.edu!math.ohio-state.edu!darwin.sura.net!news.dfn.de!scsing .switch.ch!epflnews!disuns2.epfl.ch!lglsun!madmats@ucbvax.Berkeley.EDU (Mats W]

In article <CDGv9s.DDK@inmet.camb.inmet.com>, stt@spock.camb.inmet.com (Tucker 
Taft) writes:

|> [much interesting stuff deleted]

|> By the way, one possible alternative approach to the problem,
|> which would not impose much of a burden on shared generics,
|> would be to prevent reemergence for the "=" of all record types,
|> whether tagged or untagged.  One might then argue for disallowing 
|> overriding the predefined "=" for other types (though
|> you could still overload it).  These choices are always hard...

I think your post makes a good argument in favor of forbidding the
redefinition of "=" for non-tagged non-limited types, in order to
preserve the consitency of already written Ada-83 components. I wasn't
aware of the re-emergence in record types, which I think should be
avoided at almost any price.

Well, in fact, I would take the approach that is hardest on
implementors with respect to sharing code in instances, but too many
people would disagree...

|> S. Tucker Taft     stt@inmet.com
|> Ada 9X Mapping/Revision Team
|> Intermetrics, Inc.
|> Cambridge, MA  02138

-- 
Mats Weber
e-mail: mats.weber@lglsun.epfl.ch