No, they don't look similar. As far as I can tell from a one-minute look, the solution is simply a nested for_each loop and does not provide an actual sequence adapter, despite the name cross_product_view.
That's the danger of one-minute looks... I take that back. Yes, the whole thing is a sequence and output pairs are indeed lazily generated. I am not sure if this approach can be generalized to an arbitrary number of sequences. Perhaps it can be, by making the whole thing a recursive template instead of 3 separate ones. I'd try it just to see which version results in simpler code (gut feeling: the recursive template) and in faster compilation times (gut feeling: my current implementation) but customers and management are jointly snapping at my heels...
So, in view of that, could you explain why it's not a sequence adapter?
The usual explanation: needed more coffee :) ...Max...