Re: [boost] [preprocessor]BOOST_PP_CHECK_2 with wrong number args

Subject: Re: [boost] [preprocessor]BOOST_PP_CHECK_2 with wrong number args
From: Larry Evans (cppljevans_at_[hidden])
Date: 2011-08-24 17:57:28

On 08/24/11 16:34, Edward Diener wrote:
[snip]
>> This results in the errors reported here:
>>
>> http://article.gmane.org/gmane.comp.lib.boost.devel/222795
>>
>> when that line is changed to:
>>
>> #    define BOOST_PP_CHECK_1(chk) BOOST_PP_CHECK_2(chk,_)
>>
>> the reported error goes away; however, several other errors
>> occur about too many instead of too few arguments passed to
>> BOOST_PP_CHECK_2.
>>
>> Is this a BOOST_PP bug?  If not; how can the errors reported
>> in:
>>
>> http://article.gmane.org/gmane.comp.lib.boost.devel/222795
>>
>> be avoided?
> 
> I believe it is allowable because of placeholder expressions, but this
> may have been because of C99, whereas a preprocessor that does not
> support C99 may not work.
> 
> BTW, nothing has changed with BOOST_PP_CHECK with Boost 1.47, as the
> code has appeared the way it is for a long time.
> 
> What compiler are you using ? Is there a C99 or a C++0x mode you can
> turn on in the command line somehow ?

Here's the compile command and part of output:

/home/evansl/download/gcc/4.6.0-release/install/bin/g++ -c -Wall
-ftemplate-depth-300 -O0 -fpermissive -I.
-I/home/evansl/prog_dev/boost-svn/ro/boost_1_47_0 curryable.cpp
In file included from
/home/evansl/prog_dev/boost-svn/ro/boost_1_47_0/boost/preprocessor/iteration/detail/iter/forward2.hpp:50:0,
                 from ./curryable.hpp:157,
                 from
/home/evansl/prog_dev/boost-svn/ro/boost_1_47_0/boost/preprocessor/iteration/detail/iter/forward1.hpp:47,
                 from curryable.hpp:113,
                 from curryable.cpp:1:
./curryable.hpp:117:1: error: macro "BOOST_PP_CHECK_2" requires 2
arguments, but only 1 given
./curryable.hpp:117:1: error: macro "BOOST_PP_CHECK_2" requires 2
arguments, but only 1 given

I don't see anything on the above command line that indicates
a c99 or c++0x mode, except maybe the -fpermissive.

Thanks for the help.

-regards,
Larry