boost/python/to_python_indirect.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 TO_PYTHON_INDIRECT_DWA200221_HPP
   6 # define TO_PYTHON_INDIRECT_DWA200221_HPP
   7
   8 # include <boost/python/detail/prefix.hpp>
   9
  10 # include <boost/python/object/pointer_holder.hpp>
  11 # include <boost/python/object/make_ptr_instance.hpp>
  12
  13 # include <boost/python/detail/none.hpp>
  14
  15 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
  16 # include <boost/python/converter/pytype_function.hpp>
  17 #endif
  18
  19 # include <boost/python/refcount.hpp>
  20
  21 # include <boost/type_traits/is_pointer.hpp>
  22 # include <boost/type_traits/is_polymorphic.hpp>
  23
  24 # include <boost/mpl/bool.hpp>
  25
  26 # if defined(__ICL) && __ICL < 600
  27 #  include <boost/shared_ptr.hpp>
  28 # else
  29 #  include <memory>
  30 # endif
  31
  32 namespace boost { namespace python {
  33
  34 template <class T, class MakeHolder>
  35 struct to_python_indirect
  36 {
  37     template <class U>
  38     inline PyObject*
  39     operator()(U const& ref) const
  40     {
  41         return this->execute(const_cast<U&>(ref), is_pointer<U>());
  42     }
  43 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
  44     inline PyTypeObject const*
  45     get_pytype()const
  46     {
  47         return converter::registered_pytype<T>::get_pytype();
  48     }
  49 #endif
  50  private:
  51     template <class U>
  52     inline PyObject* execute(U* ptr, mpl::true_) const
  53     {
  54         // No special NULL treatment for references
  55         if (ptr == 0)
  56             return python::detail::none();
  57         else
  58             return this->execute(*ptr, mpl::false_());
  59     }
  60
  61     template <class U>
  62     inline PyObject* execute(U const& x, mpl::false_) const
  63     {
  64         U* const p = &const_cast<U&>(x);
  65         if (is_polymorphic<U>::value)
  66         {
  67             if (PyObject* o = detail::wrapper_base_::owner(p))
  68                 return incref(o);
  69         }
  70         return MakeHolder::execute(p);
  71     }
  72 };
  73
  74 //
  75 // implementations
  76 //
  77 namespace detail
  78 {
  79   struct make_owning_holder
  80   {
  81       template <class T>
  82       static PyObject* execute(T* p)
  83       {
  84           // can't use auto_ptr with Intel 5 and VC6 Dinkum library
  85           // for some reason. We get link errors against the auto_ptr
  86           // copy constructor.
  87 # if defined(__ICL) && __ICL < 600
  88           typedef boost::shared_ptr<T> smart_pointer;
  89 # else
  90           typedef std::auto_ptr<T> smart_pointer;
  91 # endif
  92           typedef objects::pointer_holder<smart_pointer, T> holder_t;
  93
  94           smart_pointer ptr(const_cast<T*>(p));
  95           return objects::make_ptr_instance<T, holder_t>::execute(ptr);
  96       }
  97   };
  98
  99   struct make_reference_holder
 100   {
 101       template <class T>
 102       static PyObject* execute(T* p)
 103       {
 104           typedef objects::pointer_holder<T*, T> holder_t;
 105           T* q = const_cast<T*>(p);
 106           return objects::make_ptr_instance<T, holder_t>::execute(q);
 107       }
 108   };
 109 }
 110
 111 }} // namespace boost::python
 112
 113 #endif // TO_PYTHON_INDIRECT_DWA200221_HPP