SWIG with Eigen3

CMakeLists.txt

cmake_minimum_required(VERSION 3.0)

project(mytest)

FIND_PACKAGE(SWIG REQUIRED)
FIND_PACKAGE(Eigen3 REQUIRED)
INCLUDE(${SWIG_USE_FILE})

if (NOT MSVC)
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
endif()

FIND_PACKAGE(PythonLibs 2 REQUIRED)
INCLUDE_DIRECTORIES(${PYTHON_INCLUDE_PATH})
INCLUDE_DIRECTORIES(${EIGEN3_INCLUDE_DIR})

INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})

SET_SOURCE_FILES_PROPERTIES(mytest.i PROPERTIES CPLUSPLUS ON)
SWIG_ADD_MODULE(mytest python mytest.i)
SWIG_LINK_LIBRARIES(
  mytest
  ${PYTHON_LIBRARIES}
  )

mytest.hpp

#ifndef MYTEST_HPP
#define MYTEST_HPP

#include <iostream>
#include <Eigen/Dense>

void
print_norm(const Eigen::Vector3d & x) {
  std::cout << x.norm() << std::endl;
}

void
print_norms(const std::vector<Eigen::Vector3d> & xs) {
  for (const auto & x: xs) {
      std::cout << x.norm() << std::endl;
  }
}

#endif // MYTEST_HPP

mytest.i

%module mytest

%{
#define SWIG_FILE_WITH_INIT
#include "mytest.hpp"
%}

%include "mytest.hpp"

test.py

import mytest

a = [1, 1, 0]
mytest.print_norm(a)