Test Eigen Alignement issue http://eigen.tuxfamily.org/dox-devel/group__TopicStructHavingEigenMembers.html

eigen_test.cpp

/**
 * @file eigen_test.cpp
 * @authors Giulio Romualdi
 * @copyright This software may be modified and  distributed under the terms of the GNU Lesser
 * General Public License v2.1 or any later version.
 * @date 2020
 */

// Please compile the file with c++17
// e.g. g++ -mavx -std=c++17 -o eigen_test -I/usr/include/eigen3/ ./eigen_test.cpp

#include <Eigen/Dense>

class Foo {

  Eigen::Vector4d v;

public:
  Eigen::Vector4d &getV() { return v; }

  const Eigen::Vector4d &getV() const { return v; }
};


int main() {
  Foo *foo = new Foo;
  foo->getV() << 1, 2, 3, 4;

  delete foo;
  return 0;
}