From: Rob Pike <r@golang.org>
Date: Fri, 2 May 2008 06:51:33 +0000 (-0700)
Subject: Explain about pointer types for mutually recursive structures.
X-Git-Tag: weekly.2009-11-06~3784
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=f5c07634322229391ef25513a8c3efa77e423649;p=gostls13.git

Explain about pointer types for mutually recursive structures.

SVN=117463
---

diff --git a/doc/go_lang.txt b/doc/go_lang.txt
index 3479d29874..7fc7c27ffb 100644
--- a/doc/go_lang.txt
+++ b/doc/go_lang.txt
@@ -683,6 +683,15 @@ We do not allow pointer arithmetic of any kind.
   *int
   *map[string] *chan
 
+It is legal to write a pointer type (only) such as *T or **T even if T
+is not yet defined as a type name.  This allows the construction of
+mutually recursive data types such as structs:
+
+	type S1 struct { s2 *S2 }  // S2 is not yet declared
+	type S2 struct { s1 *S1 }
+
+By the end of the package source, such types must be fully declared.
+
 There are no pointer literals.