From 2d236695aa5726525ef7320bdbaa418f23d0aff9 Mon Sep 17 00:00:00 2001
From: Ryan Scheel <ryan.havvy@gmail.com>
Date: Sat, 14 Jul 2012 16:17:22 -0700
Subject: [PATCH] Use of the type  in interfaces

---
 doc/tutorial.md | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/doc/tutorial.md b/doc/tutorial.md
index 45890caef88..e481e4daf02 100644
--- a/doc/tutorial.md
+++ b/doc/tutorial.md
@@ -2508,6 +2508,18 @@ Note that functions do not explicitly have the type parameters that
 are provided by the iface. It will cause a compile-time error if you
 include them in the iface or impl.
 
+## Use of the type `self` in interfaces
+
+Interfaces may use `self` as a type where the implementation uses its
+own type. This defines an interface for testing equality of a type with
+itself:
+
+~~~~
+iface eq {
+  fn equals(other: self) -> bool;
+}
+~~~~
+
 ## Casting to an interface type
 
 The above allows us to define functions that polymorphically act on