Chris@16: /*=============================================================================
Chris@16:     Copyright (c) 2001-2011 Joel de Guzman
Chris@16: 
Chris@16:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: ==============================================================================*/
Chris@16: #if !defined(FUSION_ERASE_07232005_0534)
Chris@16: #define FUSION_ERASE_07232005_0534
Chris@16: 
Chris@101: #include <boost/fusion/support/config.hpp>
Chris@16: #include <boost/fusion/iterator/equal_to.hpp>
Chris@16: #include <boost/fusion/iterator/mpl/convert_iterator.hpp>
Chris@16: #include <boost/fusion/container/vector/vector10.hpp>
Chris@16: #include <boost/fusion/view/joint_view/joint_view.hpp>
Chris@16: #include <boost/fusion/view/iterator_range/iterator_range.hpp>
Chris@16: #include <boost/fusion/support/detail/as_fusion_element.hpp>
Chris@16: #include <boost/fusion/sequence/intrinsic/begin.hpp>
Chris@16: #include <boost/fusion/sequence/intrinsic/end.hpp>
Chris@16: #include <boost/fusion/adapted/mpl/mpl_iterator.hpp>
Chris@16: #include <boost/fusion/support/is_sequence.hpp>
Chris@16: #include <boost/utility/enable_if.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: 
Chris@16: namespace boost { namespace fusion
Chris@16: {
Chris@16:     namespace result_of
Chris@16:     {
Chris@16:         template <typename Sequence, typename First>
Chris@16:         struct compute_erase_last // put this in detail!!!
Chris@16:         {
Chris@16:             typedef typename result_of::end<Sequence>::type seq_last_type;
Chris@16:             typedef typename convert_iterator<First>::type first_type;
Chris@16:             typedef typename
Chris@16:                 mpl::if_<
Chris@16:                     result_of::equal_to<first_type, seq_last_type>
Chris@16:                   , first_type
Chris@16:                   , typename result_of::next<first_type>::type
Chris@16:                 >::type
Chris@16:             type;
Chris@16: 
Chris@101:             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@16:             static type
Chris@16:             call(First const& first, mpl::false_)
Chris@16:             {
Chris@16:                 return fusion::next(convert_iterator<First>::call(first));
Chris@16:             }
Chris@16: 
Chris@101:             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@16:             static type
Chris@16:             call(First const& first, mpl::true_)
Chris@16:             {
Chris@16:                 return convert_iterator<First>::call(first);
Chris@16:             }
Chris@16: 
Chris@101:             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@16:             static type
Chris@16:             call(First const& first)
Chris@16:             {
Chris@16:                 return call(first, result_of::equal_to<first_type, seq_last_type>());
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         struct use_default;
Chris@101: 
Chris@16:         template <class T, class Default>
Chris@16:         struct fusion_default_help
Chris@16:           : mpl::if_<
Chris@16:                 is_same<T, use_default>
Chris@16:               , Default
Chris@16:               , T
Chris@16:             >
Chris@16:         {
Chris@16:         };
Chris@101: 
Chris@16:         template <
Chris@16:             typename Sequence
Chris@16:           , typename First
Chris@16:           , typename Last = use_default>
Chris@16:         struct erase
Chris@16:         {
Chris@16:             typedef typename result_of::begin<Sequence>::type seq_first_type;
Chris@16:             typedef typename result_of::end<Sequence>::type seq_last_type;
Chris@16:             BOOST_STATIC_ASSERT((!result_of::equal_to<seq_first_type, seq_last_type>::value));
Chris@16: 
Chris@16:             typedef First FirstType;
Chris@16:             typedef typename 
Chris@16:                 fusion_default_help<
Chris@16:                     Last 
Chris@16:                   , typename compute_erase_last<Sequence, First>::type
Chris@16:                 >::type
Chris@16:             LastType;
Chris@101: 
Chris@16:             typedef typename convert_iterator<FirstType>::type first_type;
Chris@16:             typedef typename convert_iterator<LastType>::type last_type;
Chris@16:             typedef iterator_range<seq_first_type, first_type> left_type;
Chris@16:             typedef iterator_range<last_type, seq_last_type> right_type;
Chris@16:             typedef joint_view<left_type, right_type> type;
Chris@16:         };
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Sequence, typename First>
Chris@101:     BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@101:     inline typename
Chris@16:         lazy_enable_if<
Chris@16:             traits::is_sequence<Sequence>
Chris@16:           , typename result_of::erase<Sequence const, First> 
Chris@16:         >::type
Chris@16:     erase(Sequence const& seq, First const& first)
Chris@16:     {
Chris@16:         typedef result_of::erase<Sequence const, First> result_of;
Chris@16:         typedef typename result_of::left_type left_type;
Chris@16:         typedef typename result_of::right_type right_type;
Chris@16:         typedef typename result_of::type result_type;
Chris@16: 
Chris@16:         left_type left(
Chris@16:             fusion::begin(seq)
Chris@16:           , convert_iterator<First>::call(first));
Chris@16:         right_type right(
Chris@16:             fusion::result_of::compute_erase_last<Sequence const, First>::call(first)
Chris@16:           , fusion::end(seq));
Chris@16:         return result_type(left, right);
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Sequence, typename First, typename Last>
Chris@101:     BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
Chris@101:     inline typename result_of::erase<Sequence const, First, Last>::type
Chris@16:     erase(Sequence const& seq, First const& first, Last const& last)
Chris@16:     {
Chris@16:         typedef result_of::erase<Sequence const, First, Last> result_of;
Chris@16:         typedef typename result_of::left_type left_type;
Chris@16:         typedef typename result_of::right_type right_type;
Chris@16:         typedef typename result_of::type result_type;
Chris@16: 
Chris@16:         left_type left(fusion::begin(seq), first);
Chris@16:         right_type right(last, fusion::end(seq));
Chris@16:         return result_type(left, right);
Chris@16:     }
Chris@16: }}
Chris@16: 
Chris@16: #endif
Chris@16: