Chris@16: 
Chris@16: #if !defined(BOOST_PP_IS_ITERATING)
Chris@16: 
Chris@16: ///// header body
Chris@16: 
Chris@16: #ifndef BOOST_MPL_INHERIT_HPP_INCLUDED
Chris@16: #define BOOST_MPL_INHERIT_HPP_INCLUDED
Chris@16: 
Chris@16: // Copyright Aleksey Gurtovoy 2001-2004
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. 
Chris@16: // (See accompanying file LICENSE_1_0.txt or copy at 
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // See http://www.boost.org/libs/mpl for documentation.
Chris@16: 
Chris@101: // $Id$
Chris@101: // $Date$
Chris@101: // $Revision$
Chris@16: 
Chris@16: #if !defined(BOOST_MPL_PREPROCESSING_MODE)
Chris@16: #   include <boost/mpl/empty_base.hpp>
Chris@16: #   include <boost/mpl/aux_/na_spec.hpp>
Chris@16: #   include <boost/mpl/aux_/lambda_support.hpp>
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/mpl/aux_/config/use_preprocessed.hpp>
Chris@16: 
Chris@16: #if !defined(BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS) \
Chris@16:     && !defined(BOOST_MPL_PREPROCESSING_MODE)
Chris@16: 
Chris@16: #   define BOOST_MPL_PREPROCESSED_HEADER inherit.hpp
Chris@16: #   include <boost/mpl/aux_/include_preprocessed.hpp>
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16: #   include <boost/mpl/limits/arity.hpp>
Chris@16: #   include <boost/mpl/aux_/preprocessor/params.hpp>
Chris@16: #   include <boost/mpl/aux_/preprocessor/default_params.hpp>
Chris@16: #   include <boost/mpl/aux_/preprocessor/enum.hpp>
Chris@16: #   include <boost/mpl/aux_/config/ctps.hpp>
Chris@16: #   include <boost/mpl/aux_/config/dtp.hpp>
Chris@16: 
Chris@16: #   include <boost/preprocessor/iterate.hpp>
Chris@16: #   include <boost/preprocessor/dec.hpp>
Chris@16: #   include <boost/preprocessor/cat.hpp>
Chris@16: 
Chris@16: namespace boost { namespace mpl {
Chris@16: 
Chris@16: // 'inherit<T1,T2,..,Tn>' metafunction; returns an unspecified class type
Chris@16: // produced by public derivation from all metafunction's parameters 
Chris@16: // (T1,T2,..,Tn), except the parameters of 'empty_base' class type; 
Chris@16: // regardless the position and number of 'empty_base' parameters in the 
Chris@16: // metafunction's argument list, derivation from them is always a no-op;
Chris@16: // for instance:
Chris@16: //      inherit<her>::type == her
Chris@16: //      inherit<her,my>::type == struct unspecified : her, my {};
Chris@16: //      inherit<empty_base,her>::type == her
Chris@16: //      inherit<empty_base,her,empty_base,empty_base>::type == her
Chris@16: //      inherit<her,empty_base,my>::type == struct unspecified : her, my {};
Chris@16: //      inherit<empty_base,empty_base>::type == empty_base
Chris@16: 
Chris@16: #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
Chris@16: 
Chris@16: template< 
Chris@16:       typename BOOST_MPL_AUX_NA_PARAM(T1)
Chris@16:     , typename BOOST_MPL_AUX_NA_PARAM(T2)
Chris@16:     > 
Chris@16: struct inherit2
Chris@16:     : T1, T2
Chris@16: {
Chris@16:     typedef inherit2 type;
Chris@16:     BOOST_MPL_AUX_LAMBDA_SUPPORT(2, inherit2, (T1,T2))
Chris@16: };
Chris@16: 
Chris@16: template< typename T1 > 
Chris@16: struct inherit2<T1,empty_base>
Chris@16: {
Chris@16:     typedef T1 type;
Chris@16:     BOOST_MPL_AUX_LAMBDA_SUPPORT_SPEC(2, inherit2, (T1,empty_base))
Chris@16: };
Chris@16: 
Chris@16: template< typename T2 > 
Chris@16: struct inherit2<empty_base,T2>
Chris@16: {
Chris@16:     typedef T2 type;
Chris@16:     BOOST_MPL_AUX_LAMBDA_SUPPORT_SPEC(2, inherit2, (empty_base,T2))
Chris@16: };
Chris@16: 
Chris@16: // needed to disambiguate the previous two in case when both 
Chris@16: // T1 and T2 == empty_base
Chris@16: template<> 
Chris@16: struct inherit2<empty_base,empty_base>
Chris@16: {
Chris@16:     typedef empty_base type;
Chris@16:     BOOST_MPL_AUX_LAMBDA_SUPPORT_SPEC(2, inherit2, (empty_base,empty_base))
Chris@16: };
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16: template< bool C1, bool C2 >
Chris@16: struct inherit2_impl
Chris@16: {
Chris@16:     template< typename Derived, typename T1, typename T2 > struct result_ 
Chris@16:         : T1, T2
Chris@16:     {
Chris@16:         typedef Derived type_;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct inherit2_impl<false,true>
Chris@16: {
Chris@16:     template< typename Derived, typename T1, typename T2 > struct result_
Chris@16:         : T1
Chris@16:     {
Chris@16:         typedef T1 type_;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct inherit2_impl<true,false>
Chris@16: {
Chris@16:     template< typename Derived, typename T1, typename T2 > struct result_
Chris@16:         : T2 
Chris@16:     {
Chris@16:         typedef T2 type_;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct inherit2_impl<true,true>
Chris@16: {
Chris@16:     template< typename Derived, typename T1, typename T2 > struct result_
Chris@16:     {
Chris@16:         typedef T1 type_;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: template< 
Chris@16:       typename BOOST_MPL_AUX_NA_PARAM(T1)
Chris@16:     , typename BOOST_MPL_AUX_NA_PARAM(T2)
Chris@16:     > 
Chris@16: struct inherit2
Chris@16:     : aux::inherit2_impl<
Chris@16:           is_empty_base<T1>::value
Chris@16:         , is_empty_base<T2>::value
Chris@16:         >::template result_< inherit2<T1,T2>,T1,T2 >
Chris@16: {
Chris@16:     typedef typename inherit2::type_ type;
Chris@16:     BOOST_MPL_AUX_LAMBDA_SUPPORT(2, inherit2, (T1,T2))
Chris@16: };
Chris@16: 
Chris@16: #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
Chris@16: 
Chris@16: BOOST_MPL_AUX_NA_SPEC(2, inherit2)
Chris@16: 
Chris@16: #define BOOST_PP_ITERATION_PARAMS_1 \
Chris@16:     (3,(3, BOOST_MPL_LIMIT_METAFUNCTION_ARITY, <boost/mpl/inherit.hpp>))
Chris@16: #include BOOST_PP_ITERATE()
Chris@16: 
Chris@16: }}
Chris@16: 
Chris@16: #endif // BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS
Chris@16: #endif // BOOST_MPL_INHERIT_HPP_INCLUDED
Chris@16: 
Chris@16: ///// iteration
Chris@16: 
Chris@16: #else
Chris@16: #define n_ BOOST_PP_FRAME_ITERATION(1)
Chris@16: 
Chris@16: template<
Chris@16:       BOOST_MPL_PP_DEFAULT_PARAMS(n_, typename T, na)
Chris@16:     >
Chris@16: struct BOOST_PP_CAT(inherit,n_)
Chris@16:     : inherit2<
Chris@16:           typename BOOST_PP_CAT(inherit,BOOST_PP_DEC(n_))<
Chris@16:               BOOST_MPL_PP_PARAMS(BOOST_PP_DEC(n_), T)
Chris@16:             >::type
Chris@16:         , BOOST_PP_CAT(T,n_)
Chris@16:         >
Chris@16: {
Chris@16:     BOOST_MPL_AUX_LAMBDA_SUPPORT(
Chris@16:           n_
Chris@16:         , BOOST_PP_CAT(inherit,n_)
Chris@16:         , (BOOST_MPL_PP_PARAMS(n_, T))
Chris@16:         )
Chris@16: };
Chris@16: 
Chris@16: BOOST_MPL_AUX_NA_SPEC(n_, BOOST_PP_CAT(inherit,n_))
Chris@16: 
Chris@16: #if n_ == BOOST_MPL_LIMIT_METAFUNCTION_ARITY
Chris@16: /// primary template
Chris@16: template<
Chris@16:       BOOST_MPL_PP_DEFAULT_PARAMS(n_, typename T, empty_base)
Chris@16:     >
Chris@16: struct inherit
Chris@16:     : BOOST_PP_CAT(inherit,n_)<BOOST_MPL_PP_PARAMS(n_, T)>
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: // 'na' specialization
Chris@16: template<>
Chris@16: struct inherit< BOOST_MPL_PP_ENUM(5, na) >
Chris@16: {
Chris@16:     template<
Chris@16: #if !defined(BOOST_MPL_CFG_NO_DEFAULT_PARAMETERS_IN_NESTED_TEMPLATES)
Chris@16:           BOOST_MPL_PP_DEFAULT_PARAMS(n_, typename T, empty_base)
Chris@16: #else
Chris@16:           BOOST_MPL_PP_PARAMS(n_, typename T)
Chris@16: #endif
Chris@16:         >
Chris@16:     struct apply
Chris@16:         : inherit< BOOST_MPL_PP_PARAMS(n_, T) >
Chris@16:     {
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: BOOST_MPL_AUX_NA_SPEC_LAMBDA(n_, inherit)
Chris@16: BOOST_MPL_AUX_NA_SPEC_ARITY(n_, inherit)
Chris@16: BOOST_MPL_AUX_NA_SPEC_TEMPLATE_ARITY(n_, n_, inherit)
Chris@16: #endif
Chris@16: 
Chris@16: #undef n_
Chris@16: #endif // BOOST_PP_IS_ITERATING