Scalar * Vector

[JanOnGitHub]

It would be really nice if multiplications of vectors with scalars would result in the correct boost unit:

using namespace boost::units::si;
using namespace boost::units;
using namespace Eigen;
Matrix<quantity<si::velocity>,3,1> velocity = {1.0 * meter / second,1.0 * meter / second, 1.0 * meter / second};
quantity<si::time> duration = 5.0 * second;
Matrix<quantity<si::length>,3,1> length = duration * velocity;