compiler, it's doable by manually incrementing and decrementing the
reference counters to evaluate it.
-__ http://proj.llucax.com.ar/blog/dgc/blog/post/361c2fb9
+__ https://proj.llucax.com.ar/blog/dgc/blog/post/361c2fb9
__ http://en.wikipedia.org/wiki/Reference_counting
__ http://www.digitalmars.com/d/