gistfile1.py

#define BOOST_PYTHON_STATIC_LIB
#include <boost/python.hpp>
#include <boost/ref.hpp>
#include <iostream>

namespace py = boost::python;

class IntValue
{
public:
	IntValue() {}
	IntValue(int value) : value_(value) {}

	int get() const { return value_; }
	void set(int value) { value_ = value; }

	static void py_export()
	{
		py::class_<IntValue>("IntValue")
			.def("get", &IntValue::get)
			.def("set", &IntValue::set)		
			.add_property("value", &IntValue::get, &IntValue::set)
			;
	}

private:
	int value_;
};

BOOST_PYTHON_MODULE(foo)
{
	IntValue::py_export();
}

void test()
{
	try
	{
		py::object main_module = py::import("__main__");
		py::object main_namespace = main_module.attr("__dict__");

		int a = 1;
		IntValue b(2);
		IntValue c(3);
		IntValue* d = new IntValue(4);
		IntValue* e = new IntValue(5);

		py::exec("import foo", main_namespace);
		main_namespace["a"] = a;
		main_namespace["b"] = b;
		main_namespace["c"] = boost::ref(c);
		main_namespace["d"] = d;
		main_namespace["e"] = boost::ref(*e);

		py::exec(
			"a *= 10\n"
			"b.value *= 10\n"
			"c.value *= 10\n"
			"d.value *= 10\n"
			"e.value *= 10\n"
			, main_namespace);

		std::cout << a << std::endl;		// 1
		std::cout << b.get() << std::endl;	// 2
		std::cout << c.get() << std::endl;	// 30
		std::cout << d->get() << std::endl;	// 4
		std::cout << e->get() << std::endl;	// 50

		delete d;
		delete e;
	}
	catch (const py::error_already_set&)
	{
		 PyErr_Print();
	}
}

int main(int argc, char** argv)
{
	PyImport_AppendInittab("foo", initfoo);
	Py_Initialize();

	test();

	Py_Finalize();
}