Re: virtual destructor unexpected pass

[Todd Vierling <tv at pobox dot com>]

On 2 Sep 1998, Alexandre Oliva wrote:

: > It causes a link error that ~A() is undefined; I believe that the
: > destructor in A below is an error and there should be a compiler
: > error instead.
: 
: Nope, it is valid to declare an pure virtual destructor, but it *must*
: be defined anyway if you instantiate any subclass of the class.  A
: compile-time error would be wrong, because the destructor could be
: defined in another translation unit.

If it's defined in another unit for the superclass, doesn't that mean it
shouldn't have the "= 0" clause (pure virtual)?  The problem I describe in
my case is that, in the case of the pure virtual destructor, that the
compiler still puts in references to this destructor - which does not, nor
will ever, exist!  Hence the link error.

If this is standards-conformant to have a pure virtual destructor, I then
believe that the correct thing here is for the compiler to treat such a
destructor as being a null clause, i.e. {}.  Otherwise, you can't use pure
virtual destructors, because they won't link.

-- 
-- Todd Vierling (Personal tv@pobox.com; Bus. todd_vierling@xn.xerox.com)