mozilla/rust — pull request #7944 by blake2-ppc (2013-07-21 17:43:51+00:00)
Title: DList update

Factor out internal methods to pop/push list nodes so that .merge() and .rotate_to_front(), .rotate_to_back() (new methods) can be implemented without allocating nodes.

With that, some cleanup changes to DList use of Option, and adding a missing Encodable implementation.