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
>>>> 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.
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.