Re: [Boost-bugs] [Boost C++ Libraries] #4421: fix for #4400

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #4421: fix for #4400
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-07-15 21:28:43

#4421: fix for #4400
-------------------------------------------+--------------------------------
  Reporter:  Wolf Lammen <ookami1@…>       |       Owner:  no-maintainer
      Type:  Patches                       |      Status:  new          
 Milestone:  Boost 1.44.0                  |   Component:  preprocessor 
   Version:  Boost 1.44.0                  |    Severity:  Problem      
Resolution:                                |    Keywords:               
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Comment (by Wolf Lammen <ookami1@…>):

 The more I look into the preprocessor source code, the more I am
 convinced, Mr. Mensonides wanted his macros to be able to handle empty
 sequences. This is in contrast to how I read the preprocessor
 documentation:

 ''"Sequences are data structures that merge the properties of both lists
 and tuples with the exception that a seq cannot be empty.  Therefore, an
 'empty' seq is considered a special case scenario that must be handled
 separately in C++."''

 If my assumption above is right, BOOST_PP_SEQ_REST_N works incorrect for
 256 as its first argument.

 So here is an alternative patch seq_split.patch, that fixes _both_
 BOOST_PP_SEQ_REST_N and BOOST_PP_SEQ_REPLACE, and, to boot, simplifies
 code in seq/rest_n.cpp and seq/first_n.cpp.

 IMHO, it should be preferred over my previous patch seq_replace.patch,
 that fixes BOOST_PP_SEQ_REPLACE only.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/4421#comment:1>
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