| #include <Eigen/Core> |
| #include <iostream> |
| |
| template<typename Derived> |
| Eigen::Block<Derived> |
| topLeftCorner(Eigen::MatrixBase<Derived>& m, int rows, int cols) |
| { |
| return Eigen::Block<Derived>(m.derived(), 0, 0, rows, cols); |
| } |
| |
| template<typename Derived> |
| const Eigen::Block<const Derived> |
| topLeftCorner(const Eigen::MatrixBase<Derived>& m, int rows, int cols) |
| { |
| return Eigen::Block<const Derived>(m.derived(), 0, 0, rows, cols); |
| } |
| |
| int main(int, char**) |
| { |
| Eigen::Matrix4d m = Eigen::Matrix4d::Identity(); |
| std::cout << topLeftCorner(4*m, 2, 3) << std::endl; // calls the const version |
| topLeftCorner(m, 2, 3) *= 5; // calls the non-const version |
| std::cout << "Now the matrix m is:" << std::endl << m << std::endl; |
| return 0; |
| } |