2013/12/13 Sebastian Redl <sebastian.redl@getdesigned.at>

On 2013-12-13 13:56, Andrzej Krzemienski wrote:
>
> There is no harm, except that this is defined as UB. Could the rule be
> relaxed to say that if the derived type is layout-compatible with the
> base class and its destructor is implicitly declared or explicitly
> defaulted, the behaviur is well defined?

This would turn a rather simple rule...

Yes, I am proposing a more complex rule.

You're not getting rid of a category of undefined behavior.

Correct. And that is not my goal.

This is fragile.

Now it is all UB. Is it not fragile already?

It's hard to teach.

I do not expect that this thing I am proposing would be taught. What you would teach people doesn't change: use virtual or protected destructors in base classes. This thing would be only exploited by programmers that feel they know what they are doing -- at their own risk.

the simpler rule is just better by virtue of being simpler.

True.

Regards,

&rzej