Inheriting matrix_array

Dear all, I am evaluating aspects of the boost library. I wish to generate a simple implementation of ray transfer (ABCD) matricies, http://en.wikipedia.org/wiki/ABCD_matrix Since these matricies are 2x2 and will need multiplication, trace and other similar matrix like operations it makes sense to use: matrix_array<double,2> or boost::numeric::ublas::matrix_scalar<double> I wish to generate a ray transfer matrix class by overloading (say) matrix_array<double,2> and adding member functions such as: class rtm : boost::multi_array<double,2> { public: void setA(double val) { boost::multi_array<double,2>::operator()(0,0) = val; } }; Now, this is wrong... Essentially I just want to know something very simple.... When I inherit multi_array or any other class that I want to use the [] or (x,x) notation to access elements (subscript operators) how on earth do I do it? Your help will be greatly appreciated, this is driving me crazy! -ed