iterator_range/detail/begin_impl.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2011 Joel de Guzman
0003
0004     Distributed under the Boost Software License, Version 1.0. (See accompanying
0005     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 ==============================================================================*/
0007 #if !defined(FUSION_BEGIN_IMPL_05062005_1226)
0008 #define FUSION_BEGIN_IMPL_05062005_1226
0009
0010 #include <boost/fusion/support/config.hpp>
0011
0012 namespace boost { namespace fusion
0013 {
0014     struct iterator_range_tag;
0015
0016     namespace extension
0017     {
0018         template <typename Tag>
0019         struct begin_impl;
0020
0021         template <>
0022         struct begin_impl<iterator_range_tag>
0023         {
0024             template <typename Sequence>
0025             struct apply
0026             {
0027                 typedef typename Sequence::begin_type type;
0028
0029                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0030                 static type
0031                 call(Sequence& s)
0032                 {
0033                     return s.first;
0034                 }
0035             };
0036         };
0037     }
0038 }}
0039
0040 #endif
0041
0042