[Boost-bugs] [Boost C++ Libraries] #2047: [preprocessor] Support for enumerating through empty sequences

Subject: [Boost-bugs] [Boost C++ Libraries] #2047: [preprocessor] Support for enumerating through empty sequences
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-06-25 10:03:26

#2047: [preprocessor] Support for enumerating through empty sequences
-----------------------------+----------------------------------------------
 Reporter:  andysem_at_[hidden]  |        Type:  Feature Requests            
   Status:  new              |   Milestone:  Boost 1.36.0                
Component:  None             |     Version:  Boost Development Trunk     
 Severity:  Not Applicable   |    Keywords:  preprocessor seq enumeration
-----------------------------+----------------------------------------------
 Currently it is not easy to enumerate through a preprocessor sequence that
 may be empty. Currently, attempting to use BOOST_PP_SEQ_ENUM on an empty
 sequence (BOOST_PP_SEQ_NIL, for example) results in a compilation error
 saying that BOOST_PP_SEQ_ENUM_0 is not defined.

 Support for empty sequences is very useful, for example, when one wants to
 expand a sequence into function call arguments with possibility to call
 the function with no arguments.

 It seems, it is trivial to support this feature by adding "#define
 BOOST_PP_SEQ_ENUM_0" in "boost/preprocessor/seq/enum.hpp".

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/2047>
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