minad/unit — pull request #10 by pivotale20 (2011-11-15 20:15:16+00:00)
Title: Handful of changes

* `Unit#abs` for absolute value
* `Unit#zero?` so `Unit` acts more like `Numeric`
* Fix definition of Watt
* `Unit#in!` works like `Unit#in` but raises exception if units don't exactly match