ublas/traits.hpp forgot to include some headers. Here is what happens: g++ -c -x c++ /usr/include/boost/numeric/ublas/traits.hpp /usr/include/boost/numeric/ublas/traits.hpp:1428: error: ISO C++ forbids declaration of `forward_iterator_base' with no type /usr/include/boost/numeric/ublas/traits.hpp:1428: error: template-id ` forward_iterator_base<std::forward_iterator_tag, I, T>' used as a declarator /usr/include/boost/numeric/ublas/traits.hpp:1428: error: syntax error before `; ' token /usr/include/boost/numeric/ublas/traits.hpp:1436: error: ISO C++ forbids declaration of `bidirectional_iterator_base' with no type /usr/include/boost/numeric/ublas/traits.hpp:1436: error: template-id ` bidirectional_iterator_base<std::bidirectional_iterator_tag, I, T>' used as a declarator /usr/include/boost/numeric/ublas/traits.hpp:1436: error: syntax error before `; ' token /usr/include/boost/numeric/ublas/traits.hpp:1443: error: ISO C++ forbids declaration of `bidirectional_iterator_base' with no type /usr/include/boost/numeric/ublas/traits.hpp:1443: error: template-id ` bidirectional_iterator_base<boost::numeric::ublas::sparse_bidirectional_iterator_tag, I, T>' used as a declarator /usr/include/boost/numeric/ublas/traits.hpp:1443: error: syntax error before `; ' token /usr/include/boost/numeric/ublas/traits.hpp:1451: error: ISO C++ forbids declaration of `random_access_iterator_base' with no type /usr/include/boost/numeric/ublas/traits.hpp:1451: error: template-id ` random_access_iterator_base<std::bidirectional_iterator_tag, I, T>' used as a declarator /usr/include/boost/numeric/ublas/traits.hpp:1451: error: syntax error before `; ' token /usr/include/boost/numeric/ublas/traits.hpp:1458: error: ISO C++ forbids declaration of `random_access_iterator_base' with no type /usr/include/boost/numeric/ublas/traits.hpp:1458: error: template-id ` random_access_iterator_base<boost::numeric::ublas::packed_random_access_iterator_tag, I, T>' used as a declarator /usr/include/boost/numeric/ublas/traits.hpp:1458: error: syntax error before `; ' token /usr/include/boost/numeric/ublas/traits.hpp:1465: error: ISO C++ forbids declaration of `random_access_iterator_base' with no type /usr/include/boost/numeric/ublas/traits.hpp:1465: error: template-id ` random_access_iterator_base<boost::numeric::ublas::dense_random_access_iterator_tag, I, T>' used as a declarator /usr/include/boost/numeric/ublas/traits.hpp:1465: error: syntax error before `; ' token