# Double [![travis][status]][travis] ![repliee][repliee] ## Description Something can be [familiar, yet foreign at once][uncanny]—particularly when metaprogramming. **Double** allows you to use a constant even before it is defined. ## Usage ```ruby class Foo extend Double Bar end ``` [status]: https://secure.travis-ci.org/hakanensari/double.png [travis]: http://travis-ci.org/hakanensari/double [uncanny]: http://www-rohan.sdsu.edu/~amtower/uncanny.html [repliee]: http://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Repliee_Q2.jpg/344px-Repliee_Q2.jpg