Dear All, Is there specifically a way I can do the following? boost::numeric::ublas::scalar_matrix<double> mD(3,3); boost::numeric::ublas::scalar_matrix<complex<double> > mC(3,3); mC = mD; Since I can do, complex<double> a; double b; a = b; without any problem why can the same thing be done with the container? Perhaps this is a more general point with C++ containers. If I can carry out a type conversion on the contained object (e.g. double -> complex<double> assuming the double is real) is there a way I can make sure the same carries through for casting of the contained objects? -ed -- Dr. Edward Grace Photonics Group, Physics Department Blackett Laboratory Imperial College SW7 2BW t: 020 759 47719 e: ej.grace@imperial.ac.uk w: http://ptweb.op.ph.ic.ac.uk/~graceej