Sebastian Redl <sebastian.redl@getdesigned.at> writes:
Hi,
A few days ago, I made a comment about std::distance() and std::advance() being reimplemented for the new style iterator concepts. Dave said that patches are welcome.
So I sat down and wrote some preliminary versions of the two functions. They are in the attached file. The file parses cleanly, but I have not tried instantiating any of the templates yet.
I have a question, though. Does it make sense to implement boost::distance for single pass iterators? Is there anything useful that could be done with the resulting information?
Sure, you could (destructively) count the number of elements remaining in a stream. Single-pass iterators are the traversal equivalent of input iterators, and I'm pretty sure std::distance works on those.
Aside from that, I'd be happy to receive any suggestions for code improvement, adherence to Boost standards, and so on.
<snip>
template <class BidirectionalTraversableIterator, class Distance> void advance(boost::bidirectional_traversal_tag, BidirectionalTraversableIterator &i, Distance n)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ That's "traversal," not "traversable" -- Dave Abrahams Boost Consulting www.boost-consulting.com