| Brian Silverman | 72890c2 | 2015-09-19 14:37:37 -0400 | [diff] [blame] | 1 | #include <Eigen/Core> |
| 2 | #include <iostream> |
| 3 | using namespace Eigen; |
| 4 | using namespace std; |
| 5 | |
| 6 | template<typename Derived> |
| 7 | Eigen::Block<Derived, 2, 2> |
| 8 | topLeft2x2Corner(MatrixBase<Derived>& m) |
| 9 | { |
| 10 | return Eigen::Block<Derived, 2, 2>(m.derived(), 0, 0); |
| 11 | } |
| 12 | |
| 13 | template<typename Derived> |
| 14 | const Eigen::Block<const Derived, 2, 2> |
| 15 | topLeft2x2Corner(const MatrixBase<Derived>& m) |
| 16 | { |
| 17 | return Eigen::Block<const Derived, 2, 2>(m.derived(), 0, 0); |
| 18 | } |
| 19 | |
| 20 | int main(int, char**) |
| 21 | { |
| 22 | Matrix3d m = Matrix3d::Identity(); |
| 23 | cout << topLeft2x2Corner(4*m) << endl; // calls the const version |
| 24 | topLeft2x2Corner(m) *= 2; // calls the non-const version |
| 25 | cout << "Now the matrix m is:" << endl << m << endl; |
| 26 | return 0; |
| 27 | } |