[comp.lang.c++] still can't use virtuals in base constructors

dove@rocket.UUCP (Webster Dove) (05/10/89)

I have received and understand the suggestions about abstract base
classes that force the definition of a derived method.

I now want to see a discussion about the inability for the base
initializer to invoke any virtual methods.  I gather that this was
discussed previously.  Perhaps someone can send me the best of the
old discussions.  I know that during the base constructor, the derived
vtable is not yet established.  I also heard it said that this was
because the derived slot initializers have not been run.

I don't see why a preprocess could not initialize all slots and
vtables before constructors were called.  I bring this up again
because it seems to me unfortunate the the semantics of virtuals would
not be extensible to a base class.  I used to use layers of flavors
that involved intricate initialization in zetalisp and I see no way to
do this if virtuals don't exist during construction and there are no
(:after init) methods allowed.

--
		Dr. Webster Dove
		Computing Systems and Architectures
		Advanced Signal Processing Engineering (ASPEN) Dept.
		Sanders Associates (a Lockheed Company)