list/detail/begin_impl.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2011 Joel de Guzman
0003     Copyright (c) 2005 Eric Niebler
0004
0005     Distributed under the Boost Software License, Version 1.0. (See accompanying
0006     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007 ==============================================================================*/
0008 #if !defined(FUSION_BEGIN_IMPL_07172005_0824)
0009 #define FUSION_BEGIN_IMPL_07172005_0824
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <boost/mpl/if.hpp>
0013 #include <boost/type_traits/is_const.hpp>
0014
0015 namespace boost { namespace fusion
0016 {
0017     struct nil_;
0018
0019     struct cons_tag;
0020
0021     template <typename Car, typename Cdr>
0022     struct cons;
0023
0024     template <typename Cons>
0025     struct cons_iterator;
0026
0027     namespace extension
0028     {
0029         template <typename Tag>
0030         struct begin_impl;
0031
0032         template <>
0033         struct begin_impl<cons_tag>
0034         {
0035             template <typename Sequence>
0036             struct apply
0037             {
0038                 typedef cons_iterator<Sequence> type;
0039
0040                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0041                 static type
0042                 call(Sequence& t)
0043                 {
0044                     return type(t);
0045                 }
0046             };
0047         };
0048     }
0049 }}
0050
0051 #endif