Daniel James writes:

I'm not sure about this, but I think the iterator categories for joint_view, transform_view and filter_view are wrong. At the moment they are set to the category of their base iterator, but I think that they should be set to forward_iterator_tag (or maybe input_iterator_tag?) because they don't implement prior, advance or distance.

I think this is the reason that the attached file fails to compile.

Yep.

Of course, this might not be the case in the new version?

I'll make sure it's fixed. Thanks for the report! -- Aleksey Gurtovoy MetaCommunications Engineering