now we also have a examples/ directory for self-contained examples,

and this is already used to document DynBlock

doc/examples/class_DynBlock.cpp

@@ -0,0 +1,19 @@
+#include <Eigen/Core.h>
+USING_EIGEN_DATA_TYPES
+using namespace std;
+
+template<typename Scalar, typename Derived>
+Eigen::DynBlock<Derived>
+topLeftCorner(const Eigen::MatrixBase<Scalar, Derived>& m, int rows, int cols)
+{
+  return m.dynBlock(0, 0, rows, cols);
+}
+
+int main(int, char**)
+{
+  Matrix4d m = Matrix4d::identity();
+  cout << topLeftCorner(m, 2, 3) << endl;
+  topLeftCorner(m, 2, 3) *= 5;
+  cout << "Now the matrix m is:" << endl << m << endl;
+  return 0;
+}