heyday/dom-class — pull request #1 by camspiers (2013-08-07 09:13:16+00:00)
Title: UPDATE: Don't use double negation and and bitwise not in indexOf

The reasons for this are two-fold. It will make more sense to almost anyone reading the code (in my opinion using the bitwise not is just being intentionally clever). And it is slightly faster.

http://jsperf.com/indexof-not-not-tilde-vs-1