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Date: Thu, 01 May 2003 15:00:49 +0200
From: =?ISO-8859-15?Q?Rodrigo_Garc=EDa?= <rodrigo.garcia.ARROBA.epfl.ch>
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Subject: Re: Generic formal access types
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Date: 2003-05-01T15:00:49+02:00
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Martin Krischik wrote:
> Rodrigo Garc�a <rodrigo.garcia.ARROBA.epfl.ch> wrote:
> 
> should
> 
> generic
>      type Access_Type is private;
>     Null_Value : Access_Type := nul;
> 
> not work as well?

   No, it does not work. The compiler does not know until you 
instantiate the package wether Access_Type is really an access type, so 
it will not accept "null" as initial value for Null_Value. That is, in 
fact, the problem and the reason why I would want to express somehow 
that "Access_Type" must be instantiated by an actual access type without 
necessarily specifying the accessed object type.

   I do not know if I made myself clear, but you can always try to 
compile your solution in order to convince you...

Rodrigo

> 
> Regards
> 
> Martin
> 
> 
>>That seems a nice workaround, although I still have to pass two
>>parameters during instantiation. I will give it a try!
>>
>>Thanks,
>>
>>Rodrigo
>>
>>Chad R. Meiners wrote:
>>
>>How about
>>
>>generic
>>    type Access_Type is private;
>>    Null_Value : Access_Type;
>>
>>-CRM
> 
>