Re: Ada.Streams.Stream_IO.File_Type

["Robert I. Eachus" <rieachus@attbi.com>]

M�rio Amado Alves wrote:
>>...
>>but it could be implemented by putting:
>>
>>   type File_Type is new Ada.Finalization.Limited_Controlled with private;
>>
>>in the private part of package Ada.Streams.Stream_IO. I'm not quite sure if
>>such an implementation would be criticised on the grounds that objects of
>>File_Type could not then be declared other than at library level.

> Indeed it would be criticized by the many of us that find this Ada feature annoying.

So annoying that if there was such a requirement, I am sure that the ARG 
would immediately eliminate it!

I think that Nick Roberts was thinking of the rule that prevents 
creating a TYPE derived from Ada.Finalization.Limited_Controlled other 
than at the library level from having a record extension RM 3.9.1(3) and 
the note at RM 3.9.1(7).  I would like to loosen that up some in Ada 0Y 
to allow derived types of the form:

     type New_T is new tagged T;

in some nested contexts.  But it is probably not a high priority 
extension.  (Note that the declaration above is not currently 
syntactically legal.)  If it were added, though, the key would be 
insuring that there was no distributed overhead.  That's the hard part.

-- 

                                                        Robert I. Eachus

�In an ally, considerations of house, clan, planet, race are 
insignificant beside two prime questions, which are: 1. Can he shoot? 2. 
Will he aim at your enemy?� -- from the Laiden novels by Sharon Lee and 
Steve Miller.