boost/python/bases.hpp

0001 // Copyright David Abrahams 2002.
0002 // Distributed under the Boost Software License, Version 1.0. (See
0003 // accompanying file LICENSE_1_0.txt or copy at
0004 // http://www.boost.org/LICENSE_1_0.txt)
0005 #ifndef BASES_DWA2002321_HPP
0006 # define BASES_DWA2002321_HPP
0007
0008 # include <boost/python/detail/prefix.hpp>
0009 # include <boost/python/detail/type_list.hpp>
0010 # include <boost/python/detail/type_traits.hpp>
0011 # include <boost/mpl/if.hpp>
0012 # include <boost/mpl/bool.hpp>
0013 # include <boost/preprocessor/enum_params_with_a_default.hpp>
0014 # include <boost/preprocessor/enum_params.hpp>
0015
0016 namespace boost { namespace python {
0017
0018 # define BOOST_PYTHON_BASE_PARAMS BOOST_PP_ENUM_PARAMS_Z(1, BOOST_PYTHON_MAX_BASES, Base)
0019
0020   // A type list for specifying bases
0021   template < BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(BOOST_PYTHON_MAX_BASES, typename Base, mpl::void_) >
0022   struct bases : detail::type_list< BOOST_PYTHON_BASE_PARAMS >::type
0023   {};
0024
0025   namespace detail
0026   {
0027     template <class T> struct specifies_bases
0028         : mpl::false_
0029     {
0030     };
0031
0032     template < BOOST_PP_ENUM_PARAMS_Z(1, BOOST_PYTHON_MAX_BASES, class Base) >
0033     struct specifies_bases< bases< BOOST_PYTHON_BASE_PARAMS > >
0034         : mpl::true_
0035     {
0036     };
0037     template <class T, class Prev = bases<> >
0038     struct select_bases
0039         : mpl::if_<
0040                 specifies_bases<T>
0041                 , T
0042                 , Prev
0043           >
0044     {
0045     };
0046   }
0047 # undef BOOST_PYTHON_BASE_PARAMS
0048 }} // namespace boost::python
0049
0050 #endif // BASES_DWA2002321_HPP