| // Copyright David Abrahams and Nikolay Mladenov 2003. |
| // 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 RETURN_ARG_DWA2003719_HPP |
| # define RETURN_ARG_DWA2003719_HPP |
| # include <boost/python/default_call_policies.hpp> |
| # include <boost/python/detail/none.hpp> |
| # include <boost/python/detail/value_arg.hpp> |
| |
| #ifndef BOOST_PYTHON_NO_PY_SIGNATURES |
| # include <boost/python/converter/pytype_function.hpp> |
| #endif |
| |
| # include <boost/type_traits/add_reference.hpp> |
| # include <boost/type_traits/add_const.hpp> |
| |
| # include <boost/mpl/int.hpp> |
| # include <boost/mpl/at.hpp> |
| |
| # include <boost/static_assert.hpp> |
| # include <boost/python/refcount.hpp> |
| |
| # include <cstddef> |
| |
| namespace boost { namespace python { |
| |
| namespace detail |
| { |
| template <std::size_t> |
| struct return_arg_pos_argument_must_be_positive |
| # if defined(__GNUC__) && __GNUC__ >= 3 || defined(__EDG__) |
| {} |
| # endif |
| ; |
| |
| struct return_none |
| { |
| template <class T> struct apply |
| { |
| struct type |
| { |
| static bool convertible() |
| { |
| return true; |
| } |
| |
| PyObject *operator()( typename value_arg<T>::type ) const |
| { |
| return none(); |
| } |
| #ifndef BOOST_PYTHON_NO_PY_SIGNATURES |
| PyTypeObject const *get_pytype() const { return converter::expected_pytype_for_arg<T>::get_pytype() ; } |
| #endif |
| }; |
| }; |
| }; |
| } |
| |
| template < |
| std::size_t arg_pos=1 |
| , class Base = default_call_policies |
| > |
| struct return_arg : Base |
| { |
| private: |
| BOOST_STATIC_CONSTANT(bool, legal = arg_pos > 0); |
| |
| public: |
| typedef typename mpl::if_c< |
| legal |
| , detail::return_none |
| , detail::return_arg_pos_argument_must_be_positive<arg_pos> |
| // we could default to the base result_converter in case or |
| // arg_pos==0 since return arg 0 means return result, but I |
| // think it is better to issue an error instead, cause it can |
| // lead to confusions |
| >::type result_converter; |
| |
| template <class ArgumentPackage> |
| static PyObject* postcall(ArgumentPackage const& args, PyObject* result) |
| { |
| // In case of arg_pos == 0 we could simply return Base::postcall, |
| // but this is redundant |
| BOOST_STATIC_ASSERT(arg_pos > 0); |
| |
| result = Base::postcall(args,result); |
| if (!result) |
| return 0; |
| Py_DECREF(result); |
| return incref( detail::get(mpl::int_<arg_pos-1>(),args) ); |
| } |
| |
| template <class Sig> |
| struct extract_return_type : mpl::at_c<Sig, arg_pos> |
| { |
| }; |
| |
| }; |
| |
| template < |
| class Base = default_call_policies |
| > |
| struct return_self |
| : return_arg<1,Base> |
| {}; |
| |
| }} // namespace boost::python |
| |
| #endif // RETURN_ARG_DWA2003719_HPP |