Pybind11 pickle a c++ instance with dynamically allocated attributes

Suppose I have a simple class like this:

Entity.h

#include <pybind11/pybind11.h>
namespace py = pybind11;

class Entity {
public:
    int *field;
    Entity(const py::list& data);
    ~Entity();
}

Entity.cpp

#include "Entity.h"

Entity::Entity(const py::list& data) {
    field = new int[py::len(data)];
    for (int i = 0; i < length; i++) field[i] = py::int_(data[i]);
}

~Entity::Entity() { delete[] field; }

Now I bind it to Python with pybind11 like this:

Bind.cpp

#include "Entity.h"

PYBIND11_MODULE(Entity, module) {
    py::class_<Entity>(module, "Entity")
        .def(py::init<const py::list&>())
        .def(py::pickle(
            // Here I have no clue what to write
        ));
}

Pybind11 documentation suggests that the __getstate__ method be defined with py::make_tuple which should make a tuple with all the values of the attributes. The thing is, the value is a pointer, and all the data on the heap is deleted upon termination of the program.

How can I serialize an object with dynamically allocated attributes using pybind11?