123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214 |
- // 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/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
|