Chris@16: // Copyright David Abrahams 2002.
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: #ifndef MAKE_INSTANCE_DWA200296_HPP
Chris@16: # define MAKE_INSTANCE_DWA200296_HPP
Chris@16: 
Chris@16: # include <boost/python/detail/prefix.hpp>
Chris@16: # include <boost/python/object/instance.hpp>
Chris@16: # include <boost/python/converter/registered.hpp>
Chris@16: # include <boost/python/detail/decref_guard.hpp>
Chris@16: # include <boost/python/detail/none.hpp>
Chris@16: # include <boost/mpl/assert.hpp>
Chris@16: # include <boost/mpl/or.hpp>
Chris@16: # include <boost/type_traits/is_union.hpp>
Chris@16: 
Chris@16: namespace boost { namespace python { namespace objects { 
Chris@16: 
Chris@16: template <class T, class Holder, class Derived>
Chris@16: struct make_instance_impl
Chris@16: {
Chris@16:     typedef objects::instance<Holder> instance_t;
Chris@16:         
Chris@16:     template <class Arg>
Chris@16:     static inline PyObject* execute(Arg& x)
Chris@16:     {
Chris@16:         BOOST_MPL_ASSERT((mpl::or_<is_class<T>, is_union<T> >));
Chris@16: 
Chris@16:         PyTypeObject* type = Derived::get_class_object(x);
Chris@16: 
Chris@16:         if (type == 0)
Chris@16:             return python::detail::none();
Chris@16: 
Chris@16:         PyObject* raw_result = type->tp_alloc(
Chris@16:             type, objects::additional_instance_size<Holder>::value);
Chris@16:           
Chris@16:         if (raw_result != 0)
Chris@16:         {
Chris@16:             python::detail::decref_guard protect(raw_result);
Chris@16:             
Chris@16:             instance_t* instance = (instance_t*)raw_result;
Chris@16:             
Chris@16:             // construct the new C++ object and install the pointer
Chris@16:             // in the Python object.
Chris@16:             Derived::construct(&instance->storage, (PyObject*)instance, x)->install(raw_result);
Chris@16:               
Chris@16:             // Note the position of the internally-stored Holder,
Chris@16:             // for the sake of destruction
Chris@16:             Py_SIZE(instance) = offsetof(instance_t, storage);
Chris@16: 
Chris@16:             // Release ownership of the python object
Chris@16:             protect.cancel();
Chris@16:         }
Chris@16:         return raw_result;
Chris@16:     }
Chris@16: };
Chris@16:     
Chris@16: 
Chris@16: template <class T, class Holder>
Chris@16: struct make_instance
Chris@16:     : make_instance_impl<T, Holder, make_instance<T,Holder> >
Chris@16: {
Chris@16:     template <class U>
Chris@16:     static inline PyTypeObject* get_class_object(U&)
Chris@16:     {
Chris@16:         return converter::registered<T>::converters.get_class_object();
Chris@16:     }
Chris@16:     
Chris@16:     static inline Holder* construct(void* storage, PyObject* instance, reference_wrapper<T const> x)
Chris@16:     {
Chris@16:         return new (storage) Holder(instance, x);
Chris@16:     }
Chris@16: };
Chris@16:   
Chris@16: 
Chris@16: }}} // namespace boost::python::object
Chris@16: 
Chris@16: #endif // MAKE_INSTANCE_DWA200296_HPP