| /*============================================================================= |
| Copyright (c) 2001-2006 Joel de Guzman |
| |
| 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(FUSION_PRIOR_05042005_1144) |
| #define FUSION_PRIOR_05042005_1144 |
| |
| #include <boost/fusion/support/tag_of.hpp> |
| |
| namespace boost { namespace fusion |
| { |
| // Special tags: |
| struct iterator_facade_tag; // iterator facade tag |
| struct boost_array_iterator_tag; // boost::array iterator tag |
| struct mpl_iterator_tag; // mpl sequence iterator tag |
| struct std_pair_iterator_tag; // std::pair iterator tag |
| |
| namespace extension |
| { |
| template <typename Tag> |
| struct prior_impl |
| { |
| template <typename Iterator> |
| struct apply {}; |
| }; |
| |
| template <> |
| struct prior_impl<iterator_facade_tag> |
| { |
| template <typename Iterator> |
| struct apply : Iterator::template prior<Iterator> {}; |
| }; |
| |
| template <> |
| struct prior_impl<boost_array_iterator_tag>; |
| |
| template <> |
| struct prior_impl<mpl_iterator_tag>; |
| |
| template <> |
| struct prior_impl<std_pair_iterator_tag>; |
| } |
| |
| namespace result_of |
| { |
| template <typename Iterator> |
| struct prior |
| : extension::prior_impl<typename detail::tag_of<Iterator>::type>:: |
| template apply<Iterator> |
| {}; |
| } |
| |
| template <typename Iterator> |
| typename result_of::prior<Iterator>::type const |
| prior(Iterator const& i) |
| { |
| return result_of::prior<Iterator>::call(i); |
| } |
| }} |
| |
| #endif |