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 #ifndef OBJ_MGR_ARG_FROM_PYTHON_DWA2002628_HPP
6 # define OBJ_MGR_ARG_FROM_PYTHON_DWA2002628_HPP
7
8 # include <boost/python/detail/prefix.hpp>
9 # include <boost/python/detail/referent_storage.hpp>
10 # include <boost/python/detail/destroy.hpp>
11 # include <boost/python/detail/construct.hpp>
12 # include <boost/python/converter/object_manager.hpp>
13 # include <boost/python/detail/raw_pyobject.hpp>
14 # include <boost/python/tag.hpp>
15
16 //
17 // arg_from_python converters for Python type wrappers, to be used as
18 // base classes for specializations.
19 //
20 namespace boost { namespace python { namespace converter {
21
22 template <class T>
23 struct object_manager_value_arg_from_python
24 {
25 typedef T result_type;
26
27 object_manager_value_arg_from_python(PyObject*);
28 bool convertible() const;
29 T operator()() const;
30 private:
31 PyObject* m_source;
32 };
33
34 // Used for converting reference-to-object-manager arguments from
35 // python. The process used here is a little bit odd. Upon
36 // construction, we build the object manager object in the m_result
37 // object, *forcing* it to accept the source Python object by casting
38 // its pointer to detail::borrowed_reference. This is supposed to
39 // bypass any type checking of the source object. The convertible
40 // check then extracts the owned object and checks it. If the check
41 // fails, nothing else in the program ever gets to touch this strange
42 // "forced" object.
43 template <class Ref>
44 struct object_manager_ref_arg_from_python
45 {
46 typedef Ref result_type;
47
48 object_manager_ref_arg_from_python(PyObject*);
49 bool convertible() const;
50 Ref operator()() const;
51 ~object_manager_ref_arg_from_python();
52 private:
53 typename python::detail::referent_storage<Ref>::type m_result;
54 };
55
56 //
57 // implementations
58 //
59
60 template <class T>
object_manager_value_arg_from_python(PyObject * x)61 inline object_manager_value_arg_from_python<T>::object_manager_value_arg_from_python(PyObject* x)
62 : m_source(x)
63 {
64 }
65
66 template <class T>
convertible() const67 inline bool object_manager_value_arg_from_python<T>::convertible() const
68 {
69 return object_manager_traits<T>::check(m_source);
70 }
71
72 template <class T>
operator ()() const73 inline T object_manager_value_arg_from_python<T>::operator()() const
74 {
75 return T(python::detail::borrowed_reference(m_source));
76 }
77
78 template <class Ref>
object_manager_ref_arg_from_python(PyObject * x)79 inline object_manager_ref_arg_from_python<Ref>::object_manager_ref_arg_from_python(PyObject* x)
80 {
81 # if defined(__EDG_VERSION__) && __EDG_VERSION__ <= 243
82 // needed for warning suppression
83 python::detail::borrowed_reference x_ = python::detail::borrowed_reference(x);
84 python::detail::construct_referent<Ref>(&m_result.bytes, x_);
85 # else
86 python::detail::construct_referent<Ref>(&m_result.bytes, (python::detail::borrowed_reference)x);
87 # endif
88 }
89
90 template <class Ref>
~object_manager_ref_arg_from_python()91 inline object_manager_ref_arg_from_python<Ref>::~object_manager_ref_arg_from_python()
92 {
93 python::detail::destroy_referent<Ref>(this->m_result.bytes);
94 }
95
96 namespace detail
97 {
98 template <class T>
object_manager_ref_check(T const & x)99 inline bool object_manager_ref_check(T const& x)
100 {
101 return object_manager_traits<T>::check(get_managed_object(x, tag));
102 }
103 }
104
105 template <class Ref>
convertible() const106 inline bool object_manager_ref_arg_from_python<Ref>::convertible() const
107 {
108 return detail::object_manager_ref_check(
109 python::detail::void_ptr_to_reference(this->m_result.bytes, (Ref(*)())0));
110 }
111
112 template <class Ref>
operator ()() const113 inline Ref object_manager_ref_arg_from_python<Ref>::operator()() const
114 {
115 return python::detail::void_ptr_to_reference(
116 this->m_result.bytes, (Ref(*)())0);
117 }
118
119 }}} // namespace boost::python::converter
120
121 #endif // OBJ_MGR_ARG_FROM_PYTHON_DWA2002628_HPP
122