1 // Copyright David Abrahams 2002.
2 // Distributed under the Boost Software License, Version 1.0. (See
3 // accompanying file LICENSE_1_0.txt or copy at
4 // http://www.boost.org/LICENSE_1_0.txt)
5 #include <boost/python/class.hpp>
6 #include <boost/python/module.hpp>
7 #include <boost/python/def.hpp>
8 #include <boost/python/has_back_reference.hpp>
9 #include <boost/python/back_reference.hpp>
10 #include <boost/ref.hpp>
11 #include <boost/utility.hpp>
12 #include <memory>
13 #define BOOST_ENABLE_ASSERT_HANDLER
14 #include <boost/assert.hpp>
15 #include <boost/python/copy_const_reference.hpp>
16 #include <boost/python/return_value_policy.hpp>
17 #include <boost/mpl/bool.hpp>
18
19 // This test shows that a class can be wrapped "as itself" but also
20 // acquire a back-reference iff has_back_reference<> is appropriately
21 // specialized.
22 using namespace boost::python;
23
24 struct X
25 {
XX26 explicit X(int x) : x(x), magic(7654321) { ++counter; }
XX27 X(X const& rhs) : x(rhs.x), magic(7654321) { ++counter; }
~XX28 virtual ~X() { BOOST_ASSERT(magic == 7654321); magic = 6666666; x = 9999; --counter; }
29
setX30 void set(int _x) { BOOST_ASSERT(magic == 7654321); this->x = _x; }
valueX31 int value() const { BOOST_ASSERT(magic == 7654321); return x; }
countX32 static int count() { return counter; }
33 private:
34 void operator=(X const&);
35 private:
36 int x;
37 long magic;
38 static int counter;
39 };
40
41 int X::counter;
42
43 struct Y : X
44 {
YY45 Y(PyObject* self, int x) : X(x), self(self) {}
YY46 Y(PyObject* self, Y const& rhs) : X(rhs), self(self) {}
47 private:
48 Y(Y const&);
49 PyObject* self;
50 };
51
52 struct Z : X
53 {
ZZ54 Z(PyObject* self, int x) : X(x), self(self) {}
ZZ55 Z(PyObject* self, Z const& rhs) : X(rhs), self(self) {}
56 private:
57 Z(Z const&);
58 PyObject* self;
59 };
60
copy_Y(Y const & y)61 Y const& copy_Y(Y const& y) { return y; }
copy_Z(Z const & z)62 Z const& copy_Z(Z const& z) { return z; }
63
64 namespace boost { namespace python
65 {
66 template <>
67 struct has_back_reference<Y>
68 : mpl::true_
69 {
70 };
71
72 template <>
73 struct has_back_reference<Z>
74 : mpl::true_
75 {
76 };
77 }}
78
79 // prove that back_references get initialized with the right PyObject*
y_identity(back_reference<Y const &> y)80 object y_identity(back_reference<Y const&> y)
81 {
82 return y.source();
83 }
84
85 // prove that back_references contain the right value
y_equality(back_reference<Y const &> y1,Y const & y2)86 bool y_equality(back_reference<Y const&> y1, Y const& y2)
87 {
88 return &y1.get() == &y2;
89 }
90
BOOST_PYTHON_MODULE(back_reference_ext)91 BOOST_PYTHON_MODULE(back_reference_ext)
92 {
93 def("copy_Y", copy_Y, return_value_policy<copy_const_reference>());
94 def("copy_Z", copy_Z, return_value_policy<copy_const_reference>());
95 def("x_instances", &X::count);
96
97 class_<Y>("Y", init<int>())
98 .def("value", &Y::value)
99 .def("set", &Y::set)
100 ;
101
102 class_<Z,std::auto_ptr<Z> >("Z", init<int>())
103 .def("value", &Z::value)
104 .def("set", &Z::set)
105 ;
106
107 def("y_identity", y_identity);
108 def("y_equality", y_equality);
109
110 }
111
112 #include "module_tail.cpp"
113