id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
2129	iterator problem in ublas::basic_range (boost/numeric/ublas/storage.hpp)	brian.tyler@…	Gunter	"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."	Feature Requests	new	To Be Determined	uBLAS	Boost 1.35.0	Optimization