[Boost-bugs] [Boost C++ Libraries] #6010: Linkage problems in assignment.hpp

Subject: [Boost-bugs] [Boost C++ Libraries] #6010: Linkage problems in assignment.hpp
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-10-11 18:03:01

#6010: Linkage problems in assignment.hpp
---------------------------------+------------------------------------------
 Reporter:  nasos_i@…            |       Owner:  guwi17 
     Type:  Bugs                 |      Status:  new    
Milestone:  Boost 1.48.0         |   Component:  uBLAS  
  Version:  Boost 1.47.0         |    Severity:  Problem
 Keywords:                       |  
---------------------------------+------------------------------------------
 Original report in uBlas mailing list:

 {{{
 Hi,

 I started using ublas's "<<=" assignment, and I'm starting to regret it.
 First symptom: if I compile with the gcc flag -Wmissing-prototypes I get
 the following warnings:

 In file included from
 /Users/devernay/Development/stereocam/surf/CameraMatrixP.hpp:16,
                  from
 /Users/devernay/Development/stereocam/surf/TriFocalTensor/Trifocaltensor.hpp:18,
                  from
 /Users/devernay/Development/stereocam/surf/TriFocalTensor/TrifocaltensorBundleAdjustement.cpp:20:
 /opt/local/include/boost/numeric/ublas/assignment.hpp:454: warning: no
 previous prototype for 'boost::numeric::ublas::begin1_manip
 boost::numeric::ublas::begin1()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:498: warning: no
 previous prototype for 'boost::numeric::ublas::begin2_manip
 boost::numeric::ublas::begin2()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:543: warning: no
 previous prototype for 'boost::numeric::ublas::next_row_manip
 boost::numeric::ublas::next_row()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:587: warning: no
 previous prototype for 'boost::numeric::ublas::next_column_manip
 boost::numeric::ublas::next_column()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:888: warning: no
 previous prototype for
 'boost::numeric::ublas::traverse_policy::by_row_policy<boost::numeric::ublas::traverse_policy::wrap>
 boost::numeric::ublas::traverse_policy::by_row()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:892: warning: no
 previous prototype for
 'boost::numeric::ublas::traverse_policy::by_row_policy<boost::numeric::ublas::traverse_policy::wrap>
 boost::numeric::ublas::traverse_policy::by_row_wrap()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:896: warning: no
 previous prototype for
 'boost::numeric::ublas::traverse_policy::by_row_policy<boost::numeric::ublas::traverse_policy::no_wrap>
 boost::numeric::ublas::traverse_policy::by_row_no_wrap()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:900: warning: no
 previous prototype for
 'boost::numeric::ublas::traverse_policy::by_column_policy<boost::numeric::ublas::traverse_policy::wrap>
 boost::numeric::ublas::traverse_policy::by_column()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:904: warning: no
 previous prototype for
 'boost::numeric::ublas::traverse_policy::by_column_policy<boost::numeric::ublas::traverse_policy::wrap>
 boost::numeric::ublas::traverse_policy::by_column_wrap()'
 /opt/local/include/boost/numeric/ublas/assignment.hpp:908: warning: no
 previous prototype for
 'boost::numeric::ublas::traverse_policy::by_column_policy<boost::numeric::ublas::traverse_policy::no_wrap>
 boost::numeric::ublas::traverse_policy::by_column_no_wrap()'

 But the second symptom is more critical: Since these symbols are defined
 in EVERY file that includes them, I cannot link anything and I get tons of
 "multiply defined symbols".

 Looking at the file, I found out that:
 - begin1(), begin2(), and a few others are not inlined, but conditionally
 inlined, using BOOST_UBLAS_INLINE (which inlines only if NDEBUG is
 defined), and are NOT members of classes, thus the multiply defined
 symbols...
 - boost::numeric::ublas::traverse_policy::by_row() and other are just
 defined, and not inlined.

 So, really, what's the solution?
 Here's what I think:

 BOOST_UBLAS_INLINE should ONY be used for class members, NOT for
 functions, which should be simply declared "inline".

 by_row() and friends should either be inlined or declared as static
 members of an empty class.

 I tried putting the magic word "inline" in front of each of these, and it
 works.

 fred
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6010>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.