You would almost never use raw C++ when working with linear algebra stuff. You use a library like Eigen that interfaces with BLAS, LAPACK, etc., so you definite

You would almost never use raw C++ when working with linear algebra stuff. You use a library like Eigen that interfaces with BLAS, LAPACK, etc., so you definitely get all the advantages of those highly tuned libraries, plus the speed of C++ and potential flexibility of not having to make multiple array copies and so on.