* include/ruby/ruby.h (rb_data_type_t): Add comments.

And add a member variable "data", a multi-purpose storage
  area for rb_data_type.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@24835 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Fri Sep 11 05:00:19 2009  Koichi Sasada  <ko1@atdot.net>
+
+	* include/ruby/ruby.h (rb_data_type_t): Add comments.
+	  And add a member variable "data", a multi-purpose storage
+	  area for rb_data_type.
+
 Fri Sep 11 02:14:21 2009  Tanaka Akira  <akr@fsij.org>
 
 	* test/dl: use require_relative to require test_base.rb.

include/ruby/ruby.h

@@ -741,7 +741,10 @@ typedef struct rb_data_type_struct {
     void (*dmark)(void*);
     void (*dfree)(void*);
     size_t (*dsize)(const void *);
-    void *ary[4]; /* for extension */
+    void *reserved[3]; /* For future extension.
+                          This array *must* be filled with ZERO. */
+    void *data;        /* This area can be used for any purpose
+                          by a programmer who define the type. */
 } rb_data_type_t;
 
 struct RTypedData {