[Boost-bugs] [Boost C++ Libraries] #2129: iterator problem in ublas::basic_range (boost/numeric/ublas/storage.hpp)

Subject: [Boost-bugs] [Boost C++ Libraries] #2129: iterator problem in ublas::basic_range (boost/numeric/ublas/storage.hpp)
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-07-19 19:26:43

#2129: iterator problem in ublas::basic_range (boost/numeric/ublas/storage.hpp)
-----------------------------------+----------------------------------------
 Reporter:  brian.tyler_at_[hidden]  |       Owner:  guwi17 
     Type:  Bugs                   |      Status:  new    
Milestone:  Boost 1.36.0           |   Component:  uBLAS  
  Version:  Boost 1.35.0           |    Severity:  Problem
 Keywords:                         |  
-----------------------------------+----------------------------------------
 Decrementing (--) a forward iterator through a basic_range containing
 negative values throws an error (bad_index). This seems inconsistent
 because it is possible to increment (++) through such a range without
 throwing error.

 lines 937 - 941 of boost/numeric/ublas/storage.hpp read

 {{{
 const_iterator &operator -- () {
   BOOST_UBLAS_CHECK (it_ > 0, bad_index ());
   -- it_;
   return *this;
 }
 }}}


 Removing "BOOST_UBLAS_CHECK (it_ > 0, bad_index ());" solves the problem.
 Similarly for the += and -= operators.

 The documentation makes no mention of the range needing to consist only of
 positive values and this seems a rather arbitrary restriction.

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/2129>
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