Chris@102: /*//////////////////////////////////////////////////////////////////////////////
Chris@102:     Copyright (c) 2013 Jamboree
Chris@102: 
Chris@102:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@102:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@102: //////////////////////////////////////////////////////////////////////////////*/
Chris@102: #ifndef BOOST_FUSION_FLATTEN_VIEW_HPP_INCLUDED
Chris@102: #define BOOST_FUSION_FLATTEN_VIEW_HPP_INCLUDED
Chris@102: 
Chris@102: 
Chris@102: #include <boost/fusion/support/config.hpp>
Chris@102: #include <boost/mpl/bool.hpp>
Chris@102: #include <boost/mpl/single_view.hpp>
Chris@102: #include <boost/fusion/support/detail/access.hpp>
Chris@102: #include <boost/fusion/support/is_view.hpp>
Chris@102: #include <boost/fusion/support/category_of.hpp>
Chris@102: #include <boost/fusion/support/sequence_base.hpp>
Chris@102: #include <boost/fusion/sequence/intrinsic/begin.hpp>
Chris@102: #include <boost/fusion/sequence/intrinsic/end.hpp>
Chris@102: #include <boost/fusion/view/flatten_view/flatten_view_iterator.hpp>
Chris@102: 
Chris@102: 
Chris@102: namespace boost { namespace fusion
Chris@102: {
Chris@102:     struct forward_traversal_tag;
Chris@102:     struct flatten_view_tag;
Chris@102: 
Chris@102:     template <typename Sequence>
Chris@102:     struct flatten_view
Chris@102:       : sequence_base<flatten_view<Sequence> >
Chris@102:     {
Chris@102:         typedef flatten_view_tag fusion_tag;
Chris@102:         typedef fusion_sequence_tag tag; // this gets picked up by MPL
Chris@102:         typedef mpl::true_ is_view;
Chris@102:         typedef forward_traversal_tag category;
Chris@102: 
Chris@102:         typedef Sequence sequence_type;
Chris@102:         typedef typename result_of::begin<Sequence>::type first_type;
Chris@102:         typedef typename result_of::end<Sequence>::type last_type;
Chris@102: 
Chris@102:         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@102:         explicit flatten_view(Sequence& seq)
Chris@102:           : seq(seq)
Chris@102:         {}
Chris@102: 
Chris@102:         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@102:         first_type first() const { return fusion::begin(seq); }
Chris@102:         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@102:         last_type last() const { return fusion::end(seq); }
Chris@102: 
Chris@102:         typename mpl::if_<traits::is_view<Sequence>, Sequence, Sequence&>::type seq;
Chris@102:     };
Chris@102: }}
Chris@102: 
Chris@102: namespace boost { namespace fusion { namespace extension
Chris@102: {
Chris@102:     template<>
Chris@102:     struct begin_impl<flatten_view_tag>
Chris@102:     {
Chris@102:         template<typename Sequence>
Chris@102:         struct apply
Chris@102:         {
Chris@102:             typedef typename Sequence::first_type first_type;
Chris@102: 
Chris@102:             typedef typename
Chris@102:                     result_of::begin<
Chris@102:                         mpl::single_view<
Chris@102:                             typename Sequence::sequence_type> >::type
Chris@102:             root_iterator;
Chris@102: 
Chris@102:             typedef
Chris@102:                 detail::seek_descent<root_iterator, first_type>
Chris@102:             seek_descent;
Chris@102: 
Chris@102:             typedef typename seek_descent::type type;
Chris@102: 
Chris@102:             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@102:             static inline
Chris@102:             type call(Sequence& seq)
Chris@102:             {
Chris@102:                 return seek_descent::apply(root_iterator(), seq.first());
Chris@102:             }
Chris@102:         };
Chris@102:     };
Chris@102: 
Chris@102:     template<>
Chris@102:     struct end_impl<flatten_view_tag>
Chris@102:     {
Chris@102:         template<typename Sequence>
Chris@102:         struct apply
Chris@102:         {
Chris@102:             typedef typename Sequence::last_type last_type;
Chris@102: 
Chris@102:             typedef typename
Chris@102:                     result_of::end<
Chris@102:                         mpl::single_view<
Chris@102:                             typename Sequence::sequence_type> >::type
Chris@102:             type;
Chris@102: 
Chris@102:             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@102:             static inline
Chris@102:             type call(Sequence&)
Chris@102:             {
Chris@102:                 return type();
Chris@102:             }
Chris@102:         };
Chris@102:     };
Chris@102: 
Chris@102:     template<>
Chris@102:     struct size_impl<flatten_view_tag>
Chris@102:     {
Chris@102:         template <typename Sequence>
Chris@102:         struct apply
Chris@102:           : result_of::distance
Chris@102:             <
Chris@102:                 typename result_of::begin<Sequence>::type
Chris@102:               , typename result_of::end<Sequence>::type
Chris@102:             >
Chris@102:         {};
Chris@102:     };
Chris@102: 
Chris@102:     template<>
Chris@102:     struct empty_impl<flatten_view_tag>
Chris@102:     {
Chris@102:         template <typename Sequence>
Chris@102:         struct apply
Chris@102:           : result_of::empty<typename Sequence::sequence_type>
Chris@102:         {};
Chris@102:     };
Chris@102: }}}
Chris@102: 
Chris@102: 
Chris@102: #endif