Re: [boost] [preprocessor] Maybe a improvement of BOOST_PP_IS_EMPTY

Subject: Re: [boost] [preprocessor] Maybe a improvement of BOOST_PP_IS_EMPTY
From: Paul Mensonides (pmenso57_at_[hidden])
Date: 2012-11-22 08:30:17

On 11/22/2012 3:05 AM, Zhenghui Zhou wrote:

>> On 11/20/2012 7:36 PM, Edward Diener wrote:
>>
>>> On 11/20/2012 7:43 AM, Zhenghui Zhou wrote:
>>>
>>>> As I known, the undocument interface BOOST_PP_IS_EMPTY is not a general
>>>> implementation to condider emptiness. There is a undefined behaviours
>>>> when
>>>> token concatenation return a invalid preprocessing token.
>>>> Particularly, gcc
>>>> restriction reports error.
>>>>
>>>
>>> See BOOST_IS_EMPTY in my variadic macros library in the sandbox.

See also, CHAOS_PP_IS_EMPTY_NON_FUNCTION in Chaos.

http://sourceforge.net/projects/chaos-pp/

It is the closest that you can get to a general-purpose 
emptiness-detection macro.  It's only limitation is that the input 
cannot end in the name of a function-like macro.

Regards,
Paul Mensonides