1 #include <iostream>
2 #include <Eigen/Dense>
3 
4 using namespace Eigen;
5 
main()6 int main()
7 {
8   Matrix4d m;
9   m.resize(4,4); // no operation
10   std::cout << "The matrix m is of size "
11             << m.rows() << "x" << m.cols() << std::endl;
12 }
13