mozilla/rust — pull request #7931 by blake2-ppc (2013-07-20 17:22:43+00:00)
Title: Add .chain_mut_ref() for Option

First, clean up the uses of "None" and "Some" to always use consistent title case matching the variant names.

Add .chain_mut_ref() which is a missing method. A use case example for this method is extraction of an optional value from an Option value.