| |
| #ifndef BOOST_MPL_AUX_ERASE_IMPL_HPP_INCLUDED |
| #define BOOST_MPL_AUX_ERASE_IMPL_HPP_INCLUDED |
| |
| // Copyright Aleksey Gurtovoy 2000-2004 |
| // |
| // Distributed under the Boost Software License, Version 1.0. |
| // (See accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| // |
| // See http://www.boost.org/libs/mpl for documentation. |
| |
| // $Id: erase_impl.hpp 49267 2008-10-11 06:19:02Z agurtovoy $ |
| // $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $ |
| // $Revision: 49267 $ |
| |
| #include <boost/mpl/clear.hpp> |
| #include <boost/mpl/push_front.hpp> |
| #include <boost/mpl/reverse_fold.hpp> |
| #include <boost/mpl/iterator_range.hpp> |
| #include <boost/mpl/next.hpp> |
| #include <boost/mpl/aux_/na.hpp> |
| |
| namespace boost { namespace mpl { |
| |
| // default implementation; conrete sequences might override it by |
| // specializing either the 'erase_impl' or the primary 'erase' template |
| |
| template< typename Tag > |
| struct erase_impl |
| { |
| template< |
| typename Sequence |
| , typename First |
| , typename Last |
| > |
| struct apply |
| { |
| typedef typename if_na< Last,typename next<First>::type >::type last_; |
| |
| // 1st half: [begin, first) |
| typedef iterator_range< |
| typename begin<Sequence>::type |
| , First |
| > first_half_; |
| |
| // 2nd half: [last, end) ... that is, [last + 1, end) |
| typedef iterator_range< |
| last_ |
| , typename end<Sequence>::type |
| > second_half_; |
| |
| typedef typename reverse_fold< |
| second_half_ |
| , typename clear<Sequence>::type |
| , push_front<_,_> |
| >::type half_sequence_; |
| |
| typedef typename reverse_fold< |
| first_half_ |
| , half_sequence_ |
| , push_front<_,_> |
| >::type type; |
| }; |
| }; |
| |
| }} |
| |
| #endif // BOOST_MPL_AUX_ERASE_IMPL_HPP_INCLUDED |