generate a compilation error when using ReturnByValue::coeff() or coeffRef(), instead of doing an infinite recursion
generate a compilation error when using ReturnByValue::coeff() or coeffRef(),
instead of doing an infinite recursion

mjbshaw/Eigen,madlib/eigen_backup,mjbshaw/Eigen,mjbshaw/Eigen,madlib/eigen_backup,rotorliu/eigen,madlib/eigen_backup,rotorliu/eigen,madlib/eigen_backup,rotorliu/eigen,rotorliu/eigen,mjbshaw/Eigen