test_shared_cpp_owner.cpp

#include "pybind11_utils/shared_cpp_owner.h"

#include <pybind11/pybind11.h>

#include <tuple>
#include <unordered_map>

namespace py = pybind11;
using namespace pybind11::literals;

class Base;
static std::unordered_map<std::string, Base*> bases;

class Base {
 std::string name_;

public:
 Base(std::string const& name) : name_{name} { bases[name] = this; }
 virtual std::string fn() const = 0;
 virtual ~Base() { bases.erase(name_); }
};

MO2_PYBIND11_SHARED_CPP_HOLDER(Base);

class CppBase : public Base {
public:
 using Base::Base;
 std::string fn() const override { return "CppBase::fn()"; }
};

class PyBase : public Base {
public:
 using Base::Base;
 std::string fn() const override { PYBIND11_OVERRIDE_PURE(std::string, Base, fn, ); }
};

PYBIND11_MODULE(shared_cpp_owner, m)
{
 static std::shared_ptr<Base> base_ptr;

 py::class_<Base, PyBase, std::shared_ptr<Base>>(m, "Base")
 .def(py::init<std::string>())
 .def("fn", &Base::fn);

 m.def("is_alive", [](std::string const& name) {
 return bases.find(name) != bases.end();
 });

 m.def("create", [](std::string const& name) -> std::shared_ptr<Base> {
 return std::make_shared<CppBase>(name);
 });
 m.def("create_and_store", [](std::string const& name) {
 base_ptr = std::make_shared<CppBase>(name);
 return base_ptr;
 });
 m.def("store", [](std::shared_ptr<Base> ptr) {
 base_ptr = ptr;
 });
 m.def("clear", []() {
 base_ptr.reset();
 });

 m.def("call_fn", [](std::string const& name) {
 auto it = bases.find(name);
 return it != bases.end() ? it->second->fn() : "";
 });
}