code review 887042: programming_faq: added question on T vs *T method sets

programming_faq: added question on T vs *T method sets

Adding this question on Russ' recommendation - not sure if
there is some detail here I'm missing.

The associated discussion was:
http://groups.google.com/group/golang-nuts/t/ec6b27e332ed7f77

[adg, 2010-04-05 00:06:44]

Hello rsc, r (cc: golang-dev@googlegroups.com),

I'd like you to review this change.

[adg, 2010-04-05 00:08:51]

Hello rsc, r (cc: golang-dev@googlegroups.com),

Please take another look.

[rsc1, 2010-04-05 00:20:25]

Looks good but I'd like to include an example.

http://codereview.appspot.com/887042/diff/6001/7001
File doc/go_programming_faq.html (right):

http://codereview.appspot.com/887042/diff/6001/7001#newcode130
doc/go_programming_faq.html:130: <h3 id="t_tptr_visibility">
different_method_sets
would probably be easier to remember

http://codereview.appspot.com/887042/diff/6001/7001#newcode145
doc/go_programming_faq.html:145: This is because it is possible to take the
value of any pointer (and thus
(The important part here is that it affects use in interfaces.)
Rephrasing a bit and adding an example:

<p>
If an interface value contains a pointer <code>*T</code>,
a method call can obtain a value by dereferencing the pointer,
but if an interface value contains a value <code>T</code>,
there is no useful way for a method call to obtain a pointer.
</p>

<p>
For example, if not for this restriction, then this code:
</p>

<pre>
var buf bytes.Buffer
io.Copy(buf, os.Stdin)
</pre>

<p>
would copy standard input into a <i>copy</i> of <code>buf</code>,
not into <code>buf</code> itself.
This is almost never the desired behavior.
</p>

[adg, 2010-04-05 00:53:22]

Hello rsc, r (cc: golang-dev@googlegroups.com),

Please take another look.

[rsc, 2010-04-05 02:44:46]

LGTM

but wait for r

[r, 2010-04-05 06:41:34]

LGTM 

although i doubt this is the end of the issue

[adg, 2010-04-05 08:17:15]

*** Submitted as http://code.google.com/p/go/source/detail?r=a54b92816a65 ***

programming_faq: added question on T vs *T method sets

Adding this question on Russ' recommendation - not sure if
there is some detail here I'm missing.

The associated discussion was:
http://groups.google.com/group/golang-nuts/t/ec6b27e332ed7f77

R=rsc, r
CC=golang-dev
http://codereview.appspot.com/887042