| /*============================================================================= |
| 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_ADVANCE_09172005_1146) |
| #define FUSION_ADVANCE_09172005_1146 |
| |
| #include <boost/fusion/iterator/detail/advance.hpp> |
| #include <boost/fusion/support/category_of.hpp> |
| |
| #include <boost/mpl/int.hpp> |
| #include <boost/mpl/assert.hpp> |
| #include <boost/type_traits/is_same.hpp> |
| #include <boost/fusion/support/tag_of.hpp> |
| |
| namespace boost { namespace fusion |
| { |
| struct random_access_traversal_tag; |
| |
| // 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 advance_impl |
| { |
| // default implementation |
| template <typename Iterator, typename N> |
| struct apply : |
| mpl::if_c< |
| (N::value > 0) |
| , advance_detail::forward<Iterator, N::value> |
| , advance_detail::backward<Iterator, N::value> |
| >::type |
| { |
| BOOST_MPL_ASSERT_NOT((traits::is_random_access<Iterator>)); |
| }; |
| }; |
| |
| template <> |
| struct advance_impl<iterator_facade_tag> |
| { |
| template <typename Iterator, typename N> |
| struct apply : Iterator::template advance<Iterator, N> {}; |
| }; |
| |
| template <> |
| struct advance_impl<boost_array_iterator_tag>; |
| |
| template <> |
| struct advance_impl<mpl_iterator_tag>; |
| |
| template <> |
| struct advance_impl<std_pair_iterator_tag>; |
| } |
| |
| namespace result_of |
| { |
| template <typename Iterator, int N> |
| struct advance_c |
| : extension::advance_impl<typename detail::tag_of<Iterator>::type>::template apply<Iterator, mpl::int_<N> > |
| {}; |
| |
| template <typename Iterator, typename N> |
| struct advance |
| : extension::advance_impl<typename detail::tag_of<Iterator>::type>::template apply<Iterator, N> |
| {}; |
| } |
| |
| template <int N, typename Iterator> |
| inline typename result_of::advance_c<Iterator, N>::type const |
| advance_c(Iterator const& i) |
| { |
| return result_of::advance_c<Iterator, N>::call(i); |
| } |
| |
| template<typename N, typename Iterator> |
| inline typename result_of::advance<Iterator, N>::type const |
| advance(Iterator const& i) |
| { |
| return result_of::advance<Iterator, N>::call(i); |
| } |
| |
| }} // namespace boost::fusion |
| |
| #endif |