github/ReactiveCocoa — pull request #65 by joshaber (2012-09-25 02:47:34+00:00)
Title: Derived assignment

This comes out of some discussion in #63.

It abuses keyed subscripting to let you make more natural subscribable-derived assignment:

``` objc
RAC(self.someObject.someThing) = someSubscribable;
RAC_OBJ(someOtherObject, property) = someSubscribable;
```