From: timsuth@... (Tim Sutherland)
Date: 2004-10-29T09:19:00+09:00
Subject: Re: Dereferencing PtrData in Ruby/DL

In article <41816603.30703@email.byu.edu>, Jamis Buck wrote:
>Jamis Buck wrote:
>> Carl Youngblood wrote:
>> 
>>> Thanks Jamis.  Now I have another problem.  How do I get a pointer to
>>> a pointer?  Let's say I've just allocated a pointer with:
>>>
>>> mypointer = DL.malloc(DL.sizeof('P'))
>>>
>>> How do I get a pointer to that pointer?  mypointer.to_p doesn't seem 
>>> to work.
>> 
>> 
>> Try "mypointer.ptr".
>> 
>> Then "mypointer.ref" to dereference the pointer.
>
>Ack. Other way around. PtrData#ptr dereferences a pointer, while 
>PtrData#ref obtains a pointer to the pointer in question.

What do you think of the following patch to dl/doc/dl.txt? The first time I
used PtrData#ptr and PtrData#ref I had to look in the source code to see
what they did.

--- dl.txt	Sun Jan 12 06:28:59 2003
+++ dl-new.txt	Fri Oct 29 13:09:28 2004
@@ -198,10 +198,12 @@
     string is '\0'.
 
 * ptr = PtrData#ptr,+@
-  * returns the pointed value as a PtrData object ptr.
+  * returns the dereferenced value as a PtrData object ptr.
+    this is like `*ptr' in C.
 
 * ptr = PtrData#ref,-@
   * returns the reference as a PtrData object ptr.
+    this is like `&ptr' in C.
 
 * ptr = PtrData#+
   * returns the PtrData object