SI-6399 Adds API docs for Any and AnyVal

- Updates AnyVal docs to address value classes.
- Updates Any docs to address universal traits.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/library-aux/scala/Any.scala b/src/library-aux/scala/Any.scala
index 031b7d9d8c..07a9ffa8d5 100644
--- a/src/library-aux/scala/Any.scala
+++ b/src/library-aux/scala/Any.scala
@@ -10,6 +10,25 @@ package scala
 
 /** Class `Any` is the root of the Scala class hierarchy.  Every class in a Scala
  *  execution environment inherits directly or indirectly from this class.
+ *
+ * Starting with Scala 2.10 it is possible to directly extend `Any` using ''universal traits''.
+ * A ''universal trait'' is a trait that extends `Any`, only has `def`s as members, and does no initialization.
+ *
+ * The main use case for universal traits is to allow basic inheritance of methods for [[scala.AnyVal value classes]].
+ * For example,
+ *
+ * {{{
+ *     trait Printable extends Any {
+ *       def print(): Unit = println(this)
+ *     }
+ *     class Wrapper(val underlying: Int) extends AnyVal with Printable
+ *
+ *     val w = new Wrapper(3)
+ *     w.print()
+ * }}}
+ *
+ * See the [[http://docs.scala-lang.org/sips/pending/value-classes.html value classes guide]] for more
+ * details on the interplay of universal traits and value classes.
  */
 abstract class Any {
   /** Compares the receiver object (`this`) with the argument object (`that`) for equivalence.