| // Boost.Geometry (aka GGL, Generic Geometry Library) |
| |
| // Copyright (c) 2014, Oracle and/or its affiliates. |
| |
| // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle |
| |
| // Licensed under the Boost Software License version 1.0. |
| // http://www.boost.org/users/license.html |
| |
| #ifndef BOOST_GEOMETRY_ITERATORS_DETAIL_SEGMENT_ITERATOR_RANGE_SEGMENT_ITERATOR_HPP |
| #define BOOST_GEOMETRY_ITERATORS_DETAIL_SEGMENT_ITERATOR_RANGE_SEGMENT_ITERATOR_HPP |
| |
| #include <boost/mpl/assert.hpp> |
| #include <boost/type_traits/is_convertible.hpp> |
| #include <boost/iterator.hpp> |
| #include <boost/iterator/iterator_facade.hpp> |
| #include <boost/iterator/iterator_categories.hpp> |
| #include <boost/range.hpp> |
| |
| #include <boost/geometry/core/closure.hpp> |
| #include <boost/geometry/iterators/closing_iterator.hpp> |
| |
| |
| namespace boost { namespace geometry |
| { |
| |
| #ifndef DOXYGEN_NO_DETAIL |
| namespace detail { namespace segment_iterator |
| { |
| |
| |
| template <typename Range, closure_selector Closure = closure<Range>::value> |
| struct range_iterator_type |
| { |
| typedef typename boost::range_iterator<Range>::type type; |
| }; |
| |
| template <typename Range> |
| struct range_iterator_type<Range, open> |
| { |
| typedef closing_iterator<Range> type; |
| }; |
| |
| |
| |
| template <typename Range, closure_selector Closure = closure<Range>::value> |
| struct range_iterator_begin |
| { |
| static inline typename range_iterator_type<Range, Closure>::type |
| apply(Range& range) |
| { |
| return boost::begin(range); |
| } |
| }; |
| |
| template <typename Range> |
| struct range_iterator_begin<Range, open> |
| { |
| static inline typename range_iterator_type<Range, open>::type |
| apply(Range& range) |
| { |
| return closing_iterator<Range>(range); |
| } |
| }; |
| |
| |
| |
| template <typename Range, closure_selector Closure = closure<Range>::value> |
| struct range_iterator_end |
| { |
| static inline typename range_iterator_type<Range, Closure>::type |
| apply(Range& range) |
| { |
| return boost::end(range); |
| } |
| }; |
| |
| template <typename Range> |
| struct range_iterator_end<Range, open> |
| { |
| static inline typename range_iterator_type<Range, open>::type |
| apply(Range& range) |
| { |
| return closing_iterator<Range>(range, true); |
| } |
| }; |
| |
| |
| |
| |
| |
| |
| template <typename Range, typename Value, typename Reference = Value> |
| class range_segment_iterator |
| : public boost::iterator_facade |
| < |
| range_segment_iterator<Range, Value, Reference>, |
| Value, |
| boost::bidirectional_traversal_tag, |
| Reference |
| > |
| { |
| static inline bool has_less_than_two_elements(Range const& r) |
| { |
| return boost::size(r) < ((closure<Range>::value == open) ? 1u : 2u); |
| } |
| |
| public: |
| typedef typename range_iterator_type<Range>::type iterator_type; |
| |
| // default constructor |
| range_segment_iterator() |
| : m_it(), m_has_less_than_two_elements(false) |
| {} |
| |
| // for begin |
| range_segment_iterator(Range& r) |
| : m_it(range_iterator_begin<Range>::apply(r)) |
| , m_has_less_than_two_elements(has_less_than_two_elements(r)) |
| {} |
| |
| // for end |
| range_segment_iterator(Range& r, bool) |
| : m_it(range_iterator_end<Range>::apply(r)) |
| , m_has_less_than_two_elements(has_less_than_two_elements(r)) |
| { |
| if (! m_has_less_than_two_elements) |
| { |
| // the range consists of at least two items |
| --m_it; |
| } |
| } |
| |
| template |
| < |
| typename OtherRange, |
| typename OtherValue, |
| typename OtherReference |
| > |
| range_segment_iterator(range_segment_iterator |
| < |
| OtherRange, |
| OtherValue, |
| OtherReference |
| > const& other) |
| : m_it(other.m_it) |
| { |
| typedef typename range_segment_iterator |
| < |
| OtherRange, OtherValue, OtherReference |
| >::iterator_type other_iterator_type; |
| |
| static const bool are_conv |
| = boost::is_convertible<other_iterator_type, iterator_type>::value; |
| |
| BOOST_MPL_ASSERT_MSG((are_conv), NOT_CONVERTIBLE, (types<OtherRange>)); |
| } |
| |
| private: |
| friend class boost::iterator_core_access; |
| |
| template <typename Rng, typename V, typename R> |
| friend class range_segment_iterator; |
| |
| inline Reference dereference() const |
| { |
| if (m_has_less_than_two_elements) |
| { |
| return Reference(*m_it, *m_it); |
| } |
| |
| iterator_type next(m_it); |
| ++next; |
| return Reference(*m_it, *next); |
| } |
| |
| template |
| < |
| typename OtherRange, |
| typename OtherValue, |
| typename OtherReference |
| > |
| inline bool equal(range_segment_iterator |
| < |
| OtherRange, |
| OtherValue, |
| OtherReference |
| > const& other) const |
| { |
| return m_it == other.m_it; |
| } |
| |
| inline void increment() |
| { |
| ++m_it; |
| } |
| |
| inline void decrement() |
| { |
| --m_it; |
| } |
| |
| private: |
| iterator_type m_it; |
| bool m_has_less_than_two_elements; |
| }; |
| |
| |
| }} // namespace detail::segment_iterator |
| #endif // DOXYGEN_NO_DETAIL |
| |
| }} // namespace boost::geometry |
| |
| |
| #endif // BOOST_GEOMETRY_ITERATORS_DETAIL_SEGMENT_ITERATOR_RANGE_SEGMENT_ITERATOR_HPP |