Re: [boost] Is there any interest in a library that provides container

From: Dave Harris (brangdon_at_[hidden])
Date: 2005-10-26 13:08:43

In-Reply-To: <1130256273.28161.245978560_at_[hidden]>
atompkins_at_[hidden] (Andy Tompkins) wrote (abridged):
> I have read a few times that people sometimes wish that std::vector (or
> other containers) had a virtual destructor.

Generally when I've wished for that I've also wished for a few other 
virtual functions. For example, a hook which gets called whenever an item 
is added to the vector, and another which is called when items are 
removed. I think a vector which is designed to be derived from would need 
more than just a virtual destructor. If you are adding a vtable you might 
as well get some milage out of it.

On the other hand, I rarely need my container to be polymorphic - at 
least, not with respect to some library base class like std::vector or 
boost::virtual_vector. Nor do I usually want my container to have the 
entire interface of vector. For example, I may not want to allow arbitrary 
insertion at all. So I tend to write a custom wrapper class that has 
vector as a private member and just exposes what I need.

In general inheriting from anything in the std library has the drawback 
that it injects unknown junk names into your class. Inheriting from a 
boost class is hardly better.

So overall, I'm not in favour.

-- Dave Harris, Nottingham, UK.