algorithm/transformation/insert.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_INSERT_07222005_0730)
0008 #define FUSION_INSERT_07222005_0730
0009
0010 #include <boost/fusion/support/config.hpp>
0011 #include <boost/fusion/support/detail/as_fusion_element.hpp>
0012 #include <boost/fusion/iterator/mpl/convert_iterator.hpp>
0013 #include <boost/fusion/view/joint_view/joint_view.hpp>
0014 #include <boost/fusion/view/single_view/single_view.hpp>
0015 #include <boost/fusion/view/iterator_range/iterator_range.hpp>
0016 #include <boost/fusion/sequence/intrinsic/begin.hpp>
0017 #include <boost/fusion/sequence/intrinsic/end.hpp>
0018 #include <boost/fusion/adapted/mpl/mpl_iterator.hpp>
0019 #include <boost/fusion/support/is_sequence.hpp>
0020 #include <boost/utility/enable_if.hpp>
0021
0022 namespace boost { namespace fusion
0023 {
0024     namespace result_of
0025     {
0026         template <typename Sequence, typename Position, typename T>
0027         struct insert
0028         {
0029             typedef typename detail::as_fusion_element<T>::type element_type;
0030             typedef typename convert_iterator<Position>::type pos_type;
0031             typedef typename result_of::begin<Sequence>::type first_type;
0032             typedef typename result_of::end<Sequence>::type last_type;
0033
0034             typedef iterator_range<first_type, pos_type> left_type;
0035             typedef iterator_range<pos_type, last_type> right_type;
0036             typedef fusion::single_view<element_type> single_view;
0037             typedef joint_view<left_type, single_view const> left_insert_type;
0038             typedef joint_view<left_insert_type, right_type> type;
0039         };
0040     }
0041
0042     template <typename Sequence, typename Position, typename T>
0043     BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0044     inline typename
0045         lazy_enable_if<
0046             traits::is_sequence<Sequence>
0047           , result_of::insert<Sequence const, Position, T>
0048         >::type
0049     insert(Sequence const& seq, Position const& pos, T const& x)
0050     {
0051         typedef result_of::insert<
0052             Sequence const, Position, T>
0053         result_of;
0054         typedef typename result_of::left_type left_type;
0055         typedef typename result_of::right_type right_type;
0056         typedef typename result_of::single_view single_view;
0057         typedef typename result_of::left_insert_type left_insert_type;
0058         typedef typename result_of::type result;
0059
0060         left_type left(fusion::begin(seq), convert_iterator<Position>::call(pos));
0061         right_type right(convert_iterator<Position>::call(pos), fusion::end(seq));
0062         single_view insert(x);
0063         left_insert_type left_insert(left, insert);
0064         return result(left_insert, right);
0065     }
0066 }}
0067
0068 #endif
0069