Re: [boost] Alternative implementation for BOOST_PP_VARIADIC_SIZE

Subject: Re: [boost] Alternative implementation for BOOST_PP_VARIADIC_SIZE
From: Edward Diener (eldiener_at_[hidden])
Date: 2011-11-13 16:47:04

On 11/13/2011 3:49 PM, Peter Dimov wrote:
> Edward Diener wrote:
>> There is a comment number 7 which is mine at the bottom of
>> https://gustedt.wordpress.com/2010/06/08/detect-empty-macro-arguments/ .
>
> I don't see it.

I do not know why that is the case. Is the last comment number 6 that 
you see ? I know I added a comment and it shows up as 7 when I bring up 
the page. My comment is:

"#define AMACRO(x) ()
IS_EMPTY(AMACRO) is true, where of course it should be false.

This is the flaw in your presentation and it is well-known. See Paul 
Mensonides post at 
http://boost.2283326.n4.nabble.com/problem-with-BOOST-PP-IS-EMPTY-macro-td2603454.html.

I give a better and less complicated version of IS_EMPTY in my variadic 
data macro library in the Boost sandbox which is almost wholly based on 
Paul Mensonides brilliant version ( I have to do some tweaks for VC8 )."

Eddie