mozilla/rust — pull request #8354 by blake2-ppc (2013-08-06 21:44:17+00:00)
Title: External iterators for TreeMap and TreeSet

Root out the last of all `each_*` methods and the set operation methods (except `mutate_values` that does live on).

Implement a gang of iterators for difference, sym difference, intersection, union of two sets. Also implement `.rev_iter()` for the map and the set.