RE: [sv-ec] Query related to virtual methods in a class

This sentence has already been changed by mantis 1308 and approved by
the 1800 WG.

> -----Original Message-----
> From: owner-sv-ec@server.eda.org [mailto:owner-sv-ec@server.eda.org]
On
> Behalf Of Vreugdenhil, Gordon
> Sent: Friday, October 20, 2006 8:26 AM
> To: mills@lcdm-eng.com
> Cc: sv-ec@server.eda.org
> Subject: Re: [sv-ec] Query related to virtual methods in a class
> 
> 
> 
> Don Mills wrote:
> [...]
> > My conclusions are, none of the extended classes mid1, mid2, mid3
are
> > required to included and define the virtual task declared in virtual
> > base classes.
> >
> > The reason I am asking all this is due to a sentence in section
7.19:
> > "In general, if an abstract class has any virtual methods, all of
the
> > methods must be overridden (and provided with a method body) for the
> > subclass to be instantiated."
> 
> Ah - this is the root of the problem.  This sentence is confusing
> due to the earlier state of the LRM where "pure" wasn't used.  The
> "method body" part of this used to be significant and isn't any
> longer due to using "pure" to disambiguate a pure virtual from
> a virtual with a trivial implementation.
> 
> The sentence should be changed to something along the lines of the
> following:
>       If an abstract class has any pure virtual methods, any class
>       extension shall either be abstract or shall override every
>       remaining pure virtual method with an implementation of the
method.
> 
> I threw in "remaining" to allude to the fact that intermediate
> extensions (the "mid" classes) could have provided implementations
> for some of the pure virtuals already.
> 
> > This implies to me that the virtual methods must be defined in the
> > extended classes.  Ummm, that is not what I am seeing from
simulation.
> >
> > (Note that I did not make any of the task "pure".)
> 
> 
> Gord.
> 
> --
> --------------------------------------------------------------------
> Gordon Vreugdenhil                                503-685-0808
> Model Technology (Mentor Graphics)                gordonv@model.com