source: NonGTP/Boost/boost/python/extract.hpp @ 857

Revision 857, 6.0 KB checked in by igarcia, 19 years ago (diff)
Line 
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 EXTRACT_DWA200265_HPP
6# define EXTRACT_DWA200265_HPP
7
8# include <boost/python/detail/prefix.hpp>
9
10# include <boost/python/converter/object_manager.hpp>
11# include <boost/python/converter/from_python.hpp>
12# include <boost/python/converter/rvalue_from_python_data.hpp>
13# include <boost/python/converter/registered.hpp>
14# include <boost/python/converter/registered_pointee.hpp>
15
16# include <boost/python/object_core.hpp>
17# include <boost/python/refcount.hpp>
18
19# include <boost/python/detail/copy_ctor_mutates_rhs.hpp>
20# include <boost/python/detail/void_ptr.hpp>
21# include <boost/python/detail/void_return.hpp>
22# include <boost/utility.hpp>
23# include <boost/call_traits.hpp>
24
25namespace boost { namespace python {
26
27namespace api
28{
29  class object;
30}
31
32namespace converter
33{
34  template <class Ptr>
35  struct extract_pointer
36  {
37      typedef Ptr result_type;
38      extract_pointer(PyObject*);
39     
40      bool check() const;
41      Ptr operator()() const;
42     
43   private:
44      PyObject* m_source;
45      void* m_result;
46  };
47 
48  template <class Ref>
49  struct extract_reference
50  {
51      typedef Ref result_type;
52      extract_reference(PyObject*);
53     
54      bool check() const;
55      Ref operator()() const;
56     
57   private:
58      PyObject* m_source;
59      void* m_result;
60  };
61 
62  template <class T>
63  struct extract_rvalue : private noncopyable
64  {
65      typedef typename mpl::if_<
66          python::detail::copy_ctor_mutates_rhs<T>
67        , T&
68        , typename call_traits<T>::param_type
69      >::type result_type;
70
71      extract_rvalue(PyObject*);
72
73      bool check() const;
74      result_type operator()() const;
75   private:
76      PyObject* m_source;
77      mutable rvalue_from_python_data<T> m_data;
78  };
79 
80  template <class T>
81  struct extract_object_manager
82  {
83      typedef T result_type;
84      extract_object_manager(PyObject*);
85
86      bool check() const;
87      result_type operator()() const;
88   private:
89      PyObject* m_source;
90  };
91 
92  template <class T>
93  struct select_extract
94  {
95      BOOST_STATIC_CONSTANT(
96          bool, obj_mgr = is_object_manager<T>::value);
97
98      BOOST_STATIC_CONSTANT(
99          bool, ptr = is_pointer<T>::value);
100   
101      BOOST_STATIC_CONSTANT(
102          bool, ref = is_reference<T>::value);
103
104      typedef typename mpl::if_c<
105          obj_mgr
106          , extract_object_manager<T>
107          , typename mpl::if_c<
108              ptr
109              , extract_pointer<T>
110              , typename mpl::if_c<
111                  ref
112                  , extract_reference<T>
113                  , extract_rvalue<T>
114                >::type
115            >::type
116         >::type type;
117  };
118}
119
120template <class T>
121struct extract
122    : converter::select_extract<T>::type
123{
124 private:
125    typedef typename converter::select_extract<T>::type base;
126 public:
127    typedef typename base::result_type result_type;
128   
129    operator result_type() const
130    {
131        return (*this)();
132    }
133   
134    extract(PyObject*);
135    extract(api::object const&);
136};
137
138//
139// Implementations
140//
141template <class T>
142inline extract<T>::extract(PyObject* o)
143    : base(o)
144{
145}
146
147template <class T>
148inline extract<T>::extract(api::object const& o)
149    : base(o.ptr())
150{
151}
152
153namespace converter
154{
155  template <class T>
156  inline extract_rvalue<T>::extract_rvalue(PyObject* x)
157      : m_source(x)
158      , m_data(
159          (rvalue_from_python_stage1)(x, registered<T>::converters)
160          )
161  {
162  }
163 
164  template <class T>
165  inline bool
166  extract_rvalue<T>::check() const
167  {
168      return m_data.stage1.convertible;
169  }
170
171  template <class T>
172  inline typename extract_rvalue<T>::result_type
173  extract_rvalue<T>::operator()() const
174  {
175      return *(T*)(
176          // Only do the stage2 conversion once
177          m_data.stage1.convertible ==  m_data.storage.bytes
178             ? m_data.storage.bytes
179             : (rvalue_from_python_stage2)(m_source, m_data.stage1, registered<T>::converters)
180          );
181  }
182
183  template <class Ref>
184  inline extract_reference<Ref>::extract_reference(PyObject* obj)
185      : m_source(obj)
186      , m_result(
187          (get_lvalue_from_python)(obj, registered<Ref>::converters)
188          )
189  {
190  }
191
192  template <class Ref>
193  inline bool extract_reference<Ref>::check() const
194  {
195      return m_result != 0;
196  }
197
198  template <class Ref>
199  inline Ref extract_reference<Ref>::operator()() const
200  {
201      if (m_result == 0)
202          (throw_no_reference_from_python)(m_source, registered<Ref>::converters);
203     
204      return python::detail::void_ptr_to_reference(m_result, (Ref(*)())0);
205  }
206
207  template <class Ptr>
208  inline extract_pointer<Ptr>::extract_pointer(PyObject* obj)
209      : m_source(obj)
210      , m_result(
211          obj == Py_None ? 0 : (get_lvalue_from_python)(obj, registered_pointee<Ptr>::converters)
212          )
213  {
214  }
215
216  template <class Ptr>
217  inline bool extract_pointer<Ptr>::check() const
218  {
219      return m_source == Py_None || m_result != 0;
220  }
221
222  template <class Ptr>
223  inline Ptr extract_pointer<Ptr>::operator()() const
224  {
225      if (m_result == 0 && m_source != Py_None)
226          (throw_no_pointer_from_python)(m_source, registered_pointee<Ptr>::converters);
227     
228      return Ptr(m_result);
229  }
230
231  template <class T>
232  inline extract_object_manager<T>::extract_object_manager(PyObject* obj)
233      : m_source(obj)
234  {
235  }
236
237  template <class T>
238  inline bool extract_object_manager<T>::check() const
239  {
240      return object_manager_traits<T>::check(m_source);
241  }
242
243  template <class T>
244  inline T extract_object_manager<T>::operator()() const
245  {
246      return T(
247          object_manager_traits<T>::adopt(python::incref(m_source))
248          );
249  }
250}
251 
252}} // namespace boost::python::converter
253
254#endif // EXTRACT_DWA200265_HPP
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