ceph/src/boost/libs/python/include/boost/python/back_reference.hpp

   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 BACK_REFERENCE_DWA2002510_HPP
   6 # define BACK_REFERENCE_DWA2002510_HPP
   7
   8 # include <boost/python/detail/prefix.hpp>
   9
  10 # include <boost/python/object_fwd.hpp>
  11 # include <boost/python/detail/dependent.hpp>
  12 # include <boost/python/detail/raw_pyobject.hpp>
  13
  14 namespace boost { namespace python {
  15
  16 template <class T>
  17 struct back_reference
  18 {
  19  private: // types
  20     typedef typename detail::dependent<object,T>::type source_t;
  21  public:
  22     typedef T type;
  23
  24     back_reference(PyObject*, T);
  25     source_t const& source() const;
  26     T get() const;
  27  private:
  28     source_t m_source;
  29     T m_value;
  30 };
  31
  32 template<typename T>
  33 class is_back_reference
  34 {
  35  public:
  36     BOOST_STATIC_CONSTANT(bool, value = false);
  37 };
  38
  39 template<typename T>
  40 class is_back_reference<back_reference<T> >
  41 {
  42  public:
  43     BOOST_STATIC_CONSTANT(bool, value = true);
  44 };
  45
  46
  47 //
  48 // implementations
  49 //
  50 template <class T>
  51 back_reference<T>::back_reference(PyObject* p, T x)
  52     : m_source(detail::borrowed_reference(p))
  53       , m_value(x)
  54 {
  55 }
  56
  57 template <class T>
  58 typename back_reference<T>::source_t const& back_reference<T>::source() const
  59 {
  60     return m_source;
  61 }
  62
  63 template <class T>
  64 T back_reference<T>::get() const
  65 {
  66     return m_value;
  67 }
  68
  69 }} // namespace boost::python
  70
  71 #endif // BACK_REFERENCE_DWA2002510_HPP