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 BASES_DWA2002321_HPP
Chris@16: # define BASES_DWA2002321_HPP
Chris@16: 
Chris@16: # include <boost/python/detail/prefix.hpp>
Chris@16: # include <boost/type_traits/object_traits.hpp>
Chris@16: # include <boost/python/detail/type_list.hpp>
Chris@16: # include <boost/mpl/if.hpp>
Chris@16: # include <boost/mpl/bool.hpp>
Chris@16: # include <boost/preprocessor/enum_params_with_a_default.hpp>
Chris@16: # include <boost/preprocessor/enum_params.hpp>
Chris@16: 
Chris@16: namespace boost { namespace python { 
Chris@16: 
Chris@16: # define BOOST_PYTHON_BASE_PARAMS BOOST_PP_ENUM_PARAMS_Z(1, BOOST_PYTHON_MAX_BASES, Base)
Chris@16: 
Chris@16:   // A type list for specifying bases
Chris@16:   template < BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(BOOST_PYTHON_MAX_BASES, typename Base, mpl::void_) >
Chris@16:   struct bases : detail::type_list< BOOST_PYTHON_BASE_PARAMS >::type
Chris@16:   {};
Chris@16: 
Chris@16:   namespace detail
Chris@16:   {
Chris@16: # ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
Chris@16:     template <class T> struct specifies_bases
Chris@16:         : mpl::false_
Chris@16:     {
Chris@16:     };
Chris@16:     
Chris@16:     template < BOOST_PP_ENUM_PARAMS_Z(1, BOOST_PYTHON_MAX_BASES, class Base) >
Chris@16:     struct specifies_bases< bases< BOOST_PYTHON_BASE_PARAMS > >
Chris@16:         : mpl::true_
Chris@16:     {
Chris@16:     };
Chris@16: # else
Chris@16:     template < BOOST_PP_ENUM_PARAMS(BOOST_PYTHON_MAX_BASES, class Base) >
Chris@16:     static char is_bases_helper(bases< BOOST_PYTHON_BASE_PARAMS > const&);
Chris@16:     
Chris@16:     static char (& is_bases_helper(...) )[256];
Chris@16: 
Chris@16:     template <class T>
Chris@16:     struct specifies_bases
Chris@16:     {
Chris@16:      private:
Chris@16:         static typename add_reference<T>::type make();
Chris@16:         BOOST_STATIC_CONSTANT(bool, non_ref = !is_reference<T>::value);
Chris@16:      public:
Chris@16:         BOOST_STATIC_CONSTANT(bool, value = non_ref & (sizeof(is_bases_helper(make())) == 1));
Chris@16:         typedef mpl::bool_<value> type;
Chris@16:     };
Chris@16: # endif
Chris@16:     template <class T, class Prev = bases<> >
Chris@16:     struct select_bases
Chris@16:         : mpl::if_<
Chris@16:                 specifies_bases<T>
Chris@16:                 , T
Chris@16:                 , Prev
Chris@16:           >
Chris@16:     {
Chris@16:     };
Chris@16:   }
Chris@16: # undef BOOST_PYTHON_BASE_PARAMS
Chris@16: }} // namespace boost::python
Chris@16: 
Chris@16: #endif // BASES_DWA2002321_HPP