[Boost-bugs] [Boost C++ Libraries] #7306: Regression from Changeset 80234: preprocessor undefined behaviour in type_traits

Subject: [Boost-bugs] [Boost C++ Libraries] #7306: Regression from Changeset 80234: preprocessor undefined behaviour in type_traits
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-08-31 02:39:32

#7306: Regression from Changeset 80234: preprocessor undefined behaviour in
type_traits
---------------------------------------------+------------------------------
 Reporter:  Hubert Tong <hstong@…>           |       Owner:  johnmaddock
     Type:  Bugs                             |      Status:  new        
Milestone:  To Be Determined                 |   Component:  type_traits
  Version:  Boost Development Trunk          |    Severity:  Regression 
 Keywords:                                   |  
---------------------------------------------+------------------------------
 process_jam_log refuses to build for the AIX runner.
 The build appears to be choking on undefined behaviour introduced in the
 subject changeset.

 {{{
    306      BOOST_STATIC_CONSTANT(bool, value =
    307  #ifndef BOOST_NO_RVALUE_REFERENCES
    308          sizeof( _m_check(static_cast<rvalue_type>(_m_from)) ) ==
 sizeof(::boost::type_traits::yes_type)
    309  #else
    310          sizeof( _m_check(_m_from) ) ==
 sizeof(::boost::type_traits::yes_type)
    311  #endif
    312          );

 }}}

 N3290 subclause 16.3 [cpp.replace] paragraph 11 (re: invocations of a
 function-like macro):

 ...

 If there are sequences of preprocessing tokens within the list of
 arguments that would otherwise act as preprocessing directives, the
 behaviour is undefined.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7306>
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