Hello,

In functional.hpp at a couple of places, for example:

	static
        BOOST_UBLAS_INLINE
        difference_type distance_i (difference_type k, size_type /* size_i */, size_type size_j) {
            return size_j != 0 ? k / size_j : 0;
        }

k [/|%] size_[i|j] is used, where k is difference_type (signed), size_x is size_type (unsigned). This results in promoting k to unsigned, and can yield very strange results when k is negative. For example, m being a size 2x2 ublas::matrix, m.begin1() - m.end1() yields 2147483646 instad of -2. Putting a static_cast<difference_type>(size_x) in functional.hpp seems to solve the problem.

Is this known / intended? If so, what is the rationale? If it is a bug, is this a valid workaround?

BR,
Robin