// Copyright David Abrahams 2002.

// Distributed under the Boost Software License, Version 1.0. (See

// accompanying file LICENSE_1_0.txt or copy at

// http://www.boost.org/LICENSE_1_0.txt)

#include <boost/python/class.hpp>

#include <boost/python/module.hpp>

#include <boost/python/def.hpp>

#include <boost/python/has_back_reference.hpp>

#include <boost/python/back_reference.hpp>

#include <boost/ref.hpp>

#include <boost/utility.hpp>

#include <memory>

#define BOOST_ENABLE_ASSERT_HANDLER

#include <boost/assert.hpp>

#include <boost/python/copy_const_reference.hpp>

#include <boost/python/return_value_policy.hpp>

#include <boost/mpl/bool.hpp>

// This test shows that a class can be wrapped "as itself" but also

// acquire a back-reference iff has_back_reference<> is appropriately

// specialized.

using namespace boost::python;

struct X

{

explicit X(int x) : x(x), magic(7654321) { ++counter; }

X(X const& rhs) : x(rhs.x), magic(7654321) { ++counter; }

virtual ~X() { BOOST_ASSERT(magic == 7654321); magic = 6666666; x = 9999; --counter; }

void set(int _x) { BOOST_ASSERT(magic == 7654321); this->x = _x; }

int value() const { BOOST_ASSERT(magic == 7654321); return x; }

static int count() { return counter; }

private:

void operator=(X const&);

private:

int x;

long magic;

static int counter;

};

int X::counter;

struct Y : X

{

Y(PyObject* self, int x) : X(x), self(self) {}

Y(PyObject* self, Y const& rhs) : X(rhs), self(self) {}

private:

Y(Y const&);

PyObject* self;

};

struct Z : X

{

Z(PyObject* self, int x) : X(x), self(self) {}

Z(PyObject* self, Z const& rhs) : X(rhs), self(self) {}

private:

Z(Z const&);

PyObject* self;

};

Y const& copy_Y(Y const& y) { return y; }

Z const& copy_Z(Z const& z) { return z; }

namespace boost { namespace python

{

template <>

struct has_back_reference<Y>

: mpl::true_

{

};

template <>

struct has_back_reference<Z>

: mpl::true_

{

};

}}

// prove that back_references get initialized with the right PyObject*

object y_identity(back_reference<Y const&> y)

{

return y.source();

}

// prove that back_references contain the right value

bool y_equality(back_reference<Y const&> y1, Y const& y2)

{

return &y1.get() == &y2;

}

BOOST_PYTHON_MODULE(back_reference_ext)

{

def("copy_Y", copy_Y, return_value_policy<copy_const_reference>());

def("copy_Z", copy_Z, return_value_policy<copy_const_reference>());

def("x_instances", &X::count);

class_<Y>("Y", init<int>())

.def("value", &Y::value)

.def("set", &Y::set)

;

class_<Z,std::shared_ptr<Z> >("Z", init<int>())

.def("value", &Z::value)

.def("set", &Z::set)

;

def("y_identity", y_identity);

def("y_equality", y_equality);

}

#include "module_tail.cpp"