| /*////////////////////////////////////////////////////////////////////////////// |
| Copyright (c) 2013 Jamboree |
| |
| 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 BOOST_FUSION_FLATTEN_VIEW_ITERATOR_HPP_INCLUDED |
| #define BOOST_FUSION_FLATTEN_VIEW_ITERATOR_HPP_INCLUDED |
| |
| |
| #include <boost/fusion/support/config.hpp> |
| #include <boost/mpl/bool.hpp> |
| #include <boost/mpl/eval_if.hpp> |
| #include <boost/type_traits/remove_reference.hpp> |
| #include <boost/fusion/container/list/cons.hpp> |
| #include <boost/fusion/support/unused.hpp> |
| #include <boost/fusion/include/equal_to.hpp> |
| #include <boost/fusion/iterator/next.hpp> |
| #include <boost/fusion/iterator/deref.hpp> |
| #include <boost/fusion/iterator/value_of.hpp> |
| |
| |
| namespace boost { namespace fusion |
| { |
| struct forward_traversal_tag; |
| struct flatten_view_iterator_tag; |
| |
| template<class First, class Base> |
| struct flatten_view_iterator |
| : iterator_base<flatten_view_iterator<First, Base> > |
| { |
| typedef flatten_view_iterator_tag fusion_tag; |
| typedef forward_traversal_tag category; |
| |
| typedef convert_iterator<First> first_converter; |
| typedef typename first_converter::type first_type; |
| typedef Base base_type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| flatten_view_iterator(First const& first, Base const& base) |
| : first(first), base(base) |
| {} |
| |
| first_type first; |
| base_type base; |
| }; |
| }} |
| |
| namespace boost { namespace fusion { namespace detail |
| { |
| template<class Iterator, class = void> |
| struct make_descent_cons |
| { |
| typedef cons<Iterator> type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| static inline type apply(Iterator const& it) |
| { |
| return type(it); |
| } |
| }; |
| |
| template<class Iterator> |
| struct make_descent_cons<Iterator, |
| typename enable_if<traits::is_sequence< |
| typename result_of::value_of<Iterator>::type> >::type> |
| { |
| // we use 'value_of' above for convenience, assuming the value won't be reference, |
| // while we must use the regular 'deref' here for const issues... |
| typedef typename |
| remove_reference<typename result_of::deref<Iterator>::type>::type |
| sub_sequence; |
| |
| typedef typename |
| result_of::begin<sub_sequence>::type |
| sub_begin; |
| |
| typedef cons<Iterator, typename make_descent_cons<sub_begin>::type> type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| static inline type apply(Iterator const& it) |
| { |
| return type(it, make_descent_cons<sub_begin>::apply( |
| fusion::begin(*it))); |
| } |
| }; |
| |
| template<class Cons, class Base> |
| struct build_flatten_view_iterator; |
| |
| template<class Car, class Base> |
| struct build_flatten_view_iterator<cons<Car>, Base> |
| { |
| typedef flatten_view_iterator<Car, Base> type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| static inline type apply(cons<Car> const& cons, Base const& base) |
| { |
| return type(cons.car, base); |
| } |
| }; |
| |
| template<class Car, class Cdr, class Base> |
| struct build_flatten_view_iterator<cons<Car, Cdr>, Base> |
| { |
| typedef flatten_view_iterator<Car, Base> next_base; |
| typedef build_flatten_view_iterator<Cdr, next_base> next; |
| typedef typename next::type type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| static inline type apply(cons<Car, Cdr> const& cons, Base const& base) |
| { |
| return next::apply(cons.cdr, next_base(cons.car, base)); |
| } |
| }; |
| |
| template<class Base, class Iterator, class = void> |
| struct seek_descent |
| { |
| typedef make_descent_cons<Iterator> make_descent_cons_; |
| typedef typename make_descent_cons_::type cons_type; |
| typedef |
| build_flatten_view_iterator<cons_type, Base> |
| build_flatten_view_iterator_; |
| typedef typename build_flatten_view_iterator_::type type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| static inline type apply(Base const& base, Iterator const& it) |
| { |
| return build_flatten_view_iterator_::apply( |
| make_descent_cons_::apply(it), base); |
| } |
| }; |
| |
| template<class Base, class Iterator> |
| struct seek_descent<Base, Iterator, |
| typename enable_if< |
| result_of::equal_to<Iterator, typename result_of::end< |
| typename result_of::value_of<Base>::type>::type> >::type> |
| { |
| typedef typename result_of::next<Base>::type type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| static inline type apply(Base const& base, Iterator const&) |
| { |
| return fusion::next(base); |
| } |
| }; |
| }}} |
| |
| namespace boost { namespace fusion { namespace extension |
| { |
| template<> |
| struct next_impl<flatten_view_iterator_tag> |
| { |
| template<typename Iterator> |
| struct apply |
| { |
| typedef typename Iterator::first_type first_type; |
| typedef typename Iterator::base_type base_type; |
| typedef typename result_of::next<first_type>::type next_type; |
| |
| typedef detail::seek_descent<base_type, next_type> seek_descent; |
| typedef typename seek_descent::type type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| static inline |
| type call(Iterator const& it) |
| { |
| return seek_descent::apply(it.base, fusion::next(it.first)); |
| } |
| }; |
| }; |
| |
| template<> |
| struct deref_impl<flatten_view_iterator_tag> |
| { |
| template<typename Iterator> |
| struct apply |
| { |
| typedef typename |
| result_of::deref<typename Iterator::first_type>::type |
| type; |
| |
| BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
| static inline |
| type call(Iterator const& it) |
| { |
| return *it.first; |
| } |
| }; |
| }; |
| |
| template<> |
| struct value_of_impl<flatten_view_iterator_tag> |
| { |
| template<typename Iterator> |
| struct apply |
| { |
| typedef typename |
| result_of::value_of<typename Iterator::first_type>::type |
| type; |
| }; |
| }; |
| }}} |
| |
| #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408 |
| namespace std |
| { |
| template <typename First, typename Base> |
| struct iterator_traits< ::boost::fusion::flatten_view_iterator<First, Base> > |
| { }; |
| } |
| #endif |
| |
| |
| #endif |
| |