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