Re: [boost] stride_iterator_policy

From: Toon Knapen (toon_at_[hidden])
Date: 2001-08-27 09:41:10

David Abrahams wrote:
> This is a good idea, but it is common to need to select the stride at
> runtime.
Indeed, this was also on my todo list.

> 
> A couple of my colleagues made such a policy and associated generators;
> perhaps you'd like to take a look? If so, I'll see if I can convince them to
> post it.
Would be great !

> 
> An intersting fact about striding over matrices: to avoid undefined behavior
> you usually need to allocate an extra row (or column) so that there's a
> valid end iterator position.
I'm not quite following you here.
But what I think you're referring to (and what I've also been wondering 
about) is that strided_iterator can easily jump past the past-the-end 
iterator and thus begin undefined. So you need some way to detect this. 
One way is to provide the iterator_adaptor also the correct past-the-end 
iterator of the container. This would however make the strided_iterator 
less standard.

toon