1 // Copyright Gottfried Ganßauge 2003..2006.
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)
6 * Generic Conversion of opaque C++-pointers to a Python-Wrapper.
8 # ifndef OPAQUE_POINTER_CONVERTER_HPP_
9 # define OPAQUE_POINTER_CONVERTER_HPP_
11 # include <boost/python/detail/prefix.hpp>
12 # include <boost/python/lvalue_from_pytype.hpp>
13 # include <boost/python/to_python_converter.hpp>
14 # include <boost/python/converter/registrations.hpp>
15 # include <boost/python/detail/dealloc.hpp>
16 # include <boost/python/detail/none.hpp>
17 # include <boost/python/type_id.hpp>
18 # include <boost/python/errors.hpp>
20 # include <boost/type_traits/remove_pointer.hpp>
21 # include <boost/type_traits/is_pointer.hpp>
22 # include <boost/type_traits/is_void.hpp>
24 # include <boost/implicit_cast.hpp>
26 # include <boost/mpl/eval_if.hpp>
27 # include <boost/mpl/identity.hpp>
28 # include <boost/mpl/assert.hpp>
32 // registers to- and from- python conversions for a type Pointee.
35 // In addition you need to define specializations for type_id
36 // on the type pointed to by Pointer using
37 // BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID(Pointee)
39 // For an example see libs/python/test/opaque.cpp
41 namespace boost { namespace python {
43 template <class Pointee>
48 if (type_object.tp_name == 0)
50 type_object.tp_name = const_cast<char*>(type_id<Pointee*>().name());
51 if (PyType_Ready (&type_object) < 0)
53 throw error_already_set();
56 this->register_self();
60 static opaque instance;
63 static void* extract(PyObject* op)
65 return PyObject_TypeCheck(op, &type_object)
66 ? static_cast<python_instance*>(implicit_cast<void*>(op))->x
71 static PyObject* wrap(void const* px)
73 Pointee* x = *static_cast<Pointee*const*>(px);
76 return detail::none();
78 if ( python_instance *o = PyObject_New(python_instance, &type_object) )
81 return static_cast<PyObject*>(implicit_cast<void*>(o));
85 throw error_already_set();
91 converter::registration const *existing =
92 converter::registry::query (type_id<Pointee*>());
94 if ((existing == 0) || (existing->m_to_python == 0))
96 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
97 converter::registry::insert(&extract, type_id<Pointee>(), &get_pytype);
98 converter::registry::insert(&wrap, type_id<Pointee*>(), &get_pytype);
100 converter::registry::insert(&extract, type_id<Pointee>());
101 converter::registry::insert(&wrap, type_id<Pointee*>());
106 struct python_instance
112 static PyTypeObject type_object;
113 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
114 static PyTypeObject const *get_pytype(){return &type_object; }
118 template <class Pointee>
119 opaque<Pointee> opaque<Pointee>::instance;
121 template <class Pointee>
122 PyTypeObject opaque<Pointee>::type_object =
124 PyVarObject_HEAD_INIT(NULL, 0)
126 sizeof( BOOST_DEDUCED_TYPENAME opaque<Pointee>::python_instance ),
128 ::boost::python::detail::dealloc,
134 0, /* tp_as_number */
135 0, /* tp_as_sequence */
136 0, /* tp_as_mapping */
142 0, /* tp_as_buffer */
147 0, /* tp_richcompare */
148 0, /* tp_weaklistoffset */
156 0, /* tp_descr_get */
157 0, /* tp_descr_set */
158 0, /* tp_dictoffset */
167 0, /* tp_subclasses */
169 #if PYTHON_API_VERSION >= 1012
173 }} // namespace boost::python
175 // If you change the below, don't forget to alter the end of type_id.hpp
176 # define BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID(Pointee) \
177 namespace boost { namespace python { \
179 inline type_info type_id<Pointee>() \
181 return type_info (typeid (Pointee *)); \
184 inline type_info type_id<const volatile Pointee&>() \
186 return type_info (typeid (Pointee *)); \
190 # endif // OPAQUE_POINTER_CONVERTER_HPP_