From: Russ Cox <rsc@golang.org>
Date: Thu, 21 May 2009 01:16:04 +0000 (-0700)
Subject: new, stricter interface rule:
X-Git-Tag: weekly.2009-11-06~1588
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=b89a54e5c68df4d4d9b39512accd3a69b082cbba;p=gostls13.git

new, stricter interface rule:
in x.(T) x cannot be a nil (uninitialized) interface variable.

remove TODO per discussion.

DELTA=3  (1 added, 1 deleted, 1 changed)
OCL=29123
CL=29134
---

diff --git a/doc/go_spec.html b/doc/go_spec.html
index 7e66b6542f..4809d0751f 100644
--- a/doc/go_spec.html
+++ b/doc/go_spec.html
@@ -2210,7 +2210,8 @@ x.(T)
 </pre>
 
 <p>
-asserts that the value stored in <code>x</code> is of type <code>T</code>.
+asserts that <code>x</code> is not the zero interface value
+and that the value stored in <code>x</code> is of type <code>T</code>.
 The notation <code>x.(T)</code> is called a <i>type assertion</i>.
 The type of <code>x</code> must be an interface type.
 </p>
@@ -2220,7 +2221,6 @@ that the dynamic type of <code>x</code> is identical to the type <code>T</code>
 (§Type identity and compatibility).
 If <code>T</code> is an interface type, <code>x.(T)</code> asserts that the dynamic type
 of <code>T</code> implements the interface <code>T</code> (§Interface types).
-<font color=red>TODO: gri wants an error if x is already of type T.</font>
 </p>
 <p>
 If the type assertion holds, the value of the expression is the value