Re: [boost] throw_exception rev. 44954 -> g++ warnings

From: Ralf W. Grosse-Kunstleve (rwgk_at_[hidden])
Date: 2008-05-03 09:42:14

> Right, warning free code is a good idea.
>
> Nevertheless one should specify Boost include path via -isystem
> path/to/boost and not via -I path/to/boost if one doesn't want to see
> the warnings in system libraries with gcc.

That's a bit like putting black tape over a "check-engine" light.
My primary question still is:
What is the disadvantage of adding the virtual destructors?
The Stroustrup book has a very clear recommendation (below).
Why not follow this advice? I'm keen to learn the facts.
Ralf

Stroustrup 2000
Section 12.4.2 (page 319 in my edition):

Many classes require some form of cleanup for an object before it goes away. Since the abstract class lval_box cannot know if a derived class requires such cleanup, it must assume that it does require some. We ensure proper cleanup by defining a virtual destructor lval_box::~lval_box() in the base and overriding
it suitably in derived classes.
...
... We have no way of knowing exactly to which class the object pointed to by p belongs, but thanks to lval_box's virtual destructor, proper cleanup as (optionally) defined by that class' destructor will be called.