| /*============================================================================= |
| Copyright (c) 2007 Tobias Schwinger |
| |
| 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) |
| ==============================================================================*/ |
| |
| #if !defined(BOOST_FUSION_REPETITIVE_VIEW_NEXT_IMPL_HPP_INCLUDED) |
| #define BOOST_FUSION_REPETITIVE_VIEW_NEXT_IMPL_HPP_INCLUDED |
| |
| #include <boost/fusion/iterator/next.hpp> |
| #include <boost/fusion/iterator/equal_to.hpp> |
| |
| namespace boost { namespace fusion |
| { |
| struct repetitive_view_iterator_tag; |
| |
| template <typename Sequence, typename Pos> |
| struct repetitive_view_iterator; |
| |
| namespace extension |
| { |
| template <typename Tag> |
| struct next_impl; |
| |
| template <> |
| struct next_impl<repetitive_view_iterator_tag> |
| { |
| template<typename Iterator, |
| bool Last = result_of::equal_to<typename Iterator::end_type, |
| typename result_of::next< |
| typename Iterator::pos_type |
| >::type>::value > |
| struct apply_nonempty // <Iterator,false> |
| { |
| // advanvce to next position |
| |
| typedef repetitive_view_iterator< |
| typename Iterator::sequence_type, |
| typename result_of::next<typename Iterator::pos_type>::type |
| > |
| type; |
| |
| static type call(Iterator const& i) |
| { |
| return type(i.seq, next(i.pos)); |
| } |
| }; |
| template <typename Iterator> |
| struct apply_nonempty<Iterator,true> |
| { |
| // reset to beginning |
| |
| typedef repetitive_view_iterator< |
| typename Iterator::sequence_type, |
| typename Iterator::first_type |
| > |
| type; |
| |
| static type call(Iterator const& i) |
| { |
| return type(i.seq); |
| } |
| }; |
| |
| template <typename Iterator, |
| bool Empty = result_of::equal_to<typename Iterator::end_type, |
| typename Iterator::pos_type>::value > |
| struct apply // <Iterator,false> |
| : apply_nonempty<Iterator> |
| { }; |
| |
| template <typename Iterator> |
| struct apply<Iterator,true> |
| { |
| // eps^n = eps |
| |
| typedef Iterator type; |
| |
| static type call(Iterator const& i) |
| { |
| return type(i); |
| } |
| }; |
| }; |
| } |
| }} |
| |
| #endif |
| |