| /*============================================================================= |
| Copyright (c) 2001-2006 Eric Niebler |
| |
| 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) |
| ==============================================================================*/ |
| #ifndef FUSION_MULTIPLE_VIEW_05052005_0335 |
| #define FUSION_MULTIPLE_VIEW_05052005_0335 |
| |
| #include <boost/mpl/int.hpp> |
| #include <boost/mpl/bool.hpp> |
| #include <boost/mpl/next.hpp> |
| #include <boost/fusion/support/detail/access.hpp> |
| #include <boost/fusion/support/sequence_base.hpp> |
| #include <boost/fusion/support/iterator_base.hpp> |
| #include <boost/fusion/support/detail/as_fusion_element.hpp> |
| |
| namespace boost { namespace fusion |
| { |
| struct multiple_view_tag; |
| struct forward_traversal_tag; |
| struct fusion_sequence_tag; |
| |
| template<typename Size, typename T> |
| struct multiple_view |
| : sequence_base<multiple_view<Size, T> > |
| { |
| typedef multiple_view_tag fusion_tag; |
| typedef fusion_sequence_tag tag; // this gets picked up by MPL |
| typedef forward_traversal_tag category; |
| typedef mpl::true_ is_view; |
| typedef mpl::int_<Size::value> size; |
| typedef T value_type; |
| |
| multiple_view() |
| : val() |
| {} |
| |
| explicit multiple_view(typename detail::call_param<T>::type val) |
| : val(val) |
| {} |
| |
| value_type val; |
| }; |
| |
| template<typename Size, typename T> |
| inline multiple_view<Size, typename detail::as_fusion_element<T>::type> |
| make_multiple_view(T const& v) |
| { |
| return multiple_view<Size, typename detail::as_fusion_element<T>::type>(v); |
| } |
| |
| struct multiple_view_iterator_tag; |
| struct forward_traversal_tag; |
| |
| template<typename Index, typename MultipleView> |
| struct multiple_view_iterator |
| : iterator_base<multiple_view_iterator<Index, MultipleView> > |
| { |
| typedef multiple_view_iterator_tag fusion_tag; |
| typedef forward_traversal_tag category; |
| typedef typename MultipleView::value_type value_type; |
| typedef MultipleView multiple_view_type; |
| typedef Index index; |
| |
| explicit multiple_view_iterator(multiple_view_type const &view_) |
| : view(view_) |
| {} |
| |
| multiple_view_type view; |
| }; |
| |
| namespace extension |
| { |
| template <typename Tag> |
| struct next_impl; |
| |
| template <> |
| struct next_impl<multiple_view_iterator_tag> |
| { |
| template <typename Iterator> |
| struct apply |
| { |
| typedef multiple_view_iterator< |
| typename mpl::next<typename Iterator::index>::type |
| , typename Iterator::multiple_view_type |
| > type; |
| |
| static type |
| call(Iterator const &where) |
| { |
| return type(where.view); |
| } |
| }; |
| }; |
| |
| template <typename Tag> |
| struct end_impl; |
| |
| template <> |
| struct end_impl<multiple_view_tag> |
| { |
| template <typename Sequence> |
| struct apply |
| { |
| typedef multiple_view_iterator< |
| typename Sequence::size |
| , Sequence |
| > type; |
| |
| static type |
| call(Sequence &seq) |
| { |
| return type(seq); |
| } |
| }; |
| }; |
| |
| template <typename Tag> |
| struct deref_impl; |
| |
| template <> |
| struct deref_impl<multiple_view_iterator_tag> |
| { |
| template <typename Iterator> |
| struct apply |
| { |
| typedef typename Iterator::value_type type; |
| |
| static type |
| call(Iterator const& i) |
| { |
| return i.view.val; |
| } |
| }; |
| }; |
| |
| template <typename Tag> |
| struct begin_impl; |
| |
| template <> |
| struct begin_impl<multiple_view_tag> |
| { |
| template <typename Sequence> |
| struct apply |
| { |
| typedef multiple_view_iterator< |
| mpl::int_<0> |
| , Sequence |
| > type; |
| |
| static type |
| call(Sequence &seq) |
| { |
| return type(seq); |
| } |
| }; |
| }; |
| |
| template <typename Tag> |
| struct value_of_impl; |
| |
| template <> |
| struct value_of_impl<multiple_view_iterator_tag> |
| { |
| template <typename Iterator> |
| struct apply |
| { |
| typedef typename Iterator::multiple_view_type multiple_view_type; |
| typedef typename multiple_view_type::value_type type; |
| }; |
| }; |
| } |
| }} |
| |
| #endif |
| |
| |