🚀 go-pugleaf

In <488hg6$prm@engnews1.eng.sun.com>, clamage@Eng.Sun.COM (Steve Clamage) writes:
>Virtual things are associated with an object; static things are not
>associated with any object.

I think maybe you need to "think outside the box" a bit more :-).  The whole 
issue is whether such a restrictive viewpoint is appropriate.  A reasonable 
point of view is that virtual and static are completely orthogonal and
intersect quite nicely.  Virtual things depend on the actual type of the 
referenced object.  Static things are associated with the class of an object 
rather than with a specific instance.  Ergo, static virtual things depend on the
actual class of the referenced object, rather than the static type of the
expression by which you reference it.

>That's workable, if a bit kludgy, but it isn't obvious to me (among others)
>what programming problem is solved by this extra complication that can't be
>solved adequately already.  

I won't try to defend virtual data members, but static virtual functions solve 
the problem of safely invoking derived class code from within base class 
constructors and destructors (a programming problem which can't be solved
adequately already).

>By that, I don't mean "Can you think of a problem
>that this extension solves?" I do mean "Considering the criteria expressed in
>D&E and other places for extensions to C++, is this a good candidate?"

No.  I say that because one of those "other places" is here and clearly the 
criteria expressed implicitly during discussion of this issue indicates that 
the value of static virtual functions is too subtle to be appreciated, I guess.
That's cool.  I can't appreciate the subtle value in having all my for loops
being broken.  I do, however, acknowledge the arguments in favor of doing that.

>---
>Steve Clamage, stephen.clamage@eng.sun.com

Bill Law


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