Chris@102: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@102: 
Chris@102: // Copyright (c) 2014, Oracle and/or its affiliates.
Chris@102: 
Chris@102: // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
Chris@102: 
Chris@102: // Licensed under the Boost Software License version 1.0.
Chris@102: // http://www.boost.org/users/license.html
Chris@102: 
Chris@102: #ifndef BOOST_GEOMETRY_ITERATORS_CONCATENATE_ITERATOR_HPP
Chris@102: #define BOOST_GEOMETRY_ITERATORS_CONCATENATE_ITERATOR_HPP
Chris@102: 
Chris@102: #include <boost/assert.hpp>
Chris@102: #include <boost/mpl/assert.hpp>
Chris@102: #include <boost/type_traits/is_convertible.hpp>
Chris@102: #include <boost/iterator.hpp>
Chris@102: #include <boost/iterator/iterator_facade.hpp>
Chris@102: #include <boost/iterator/iterator_categories.hpp>
Chris@102: 
Chris@102: 
Chris@102: namespace boost { namespace geometry
Chris@102: {
Chris@102: 
Chris@102: 
Chris@102: 
Chris@102: template
Chris@102: <
Chris@102:     typename Iterator1,
Chris@102:     typename Iterator2,
Chris@102:     typename Value,
Chris@102:     typename Reference = Value&
Chris@102: >
Chris@102: class concatenate_iterator
Chris@102:     : public boost::iterator_facade
Chris@102:         <
Chris@102:             concatenate_iterator<Iterator1, Iterator2, Value, Reference>,
Chris@102:             Value,
Chris@102:             boost::bidirectional_traversal_tag,
Chris@102:             Reference
Chris@102:         >
Chris@102: {
Chris@102: private:
Chris@102:     Iterator1 m_it1, m_end1;
Chris@102:     Iterator2 m_begin2, m_it2;
Chris@102: 
Chris@102: public:
Chris@102:     typedef Iterator1 first_iterator_type;
Chris@102:     typedef Iterator2 second_iterator_type;
Chris@102: 
Chris@102:     // default constructor
Chris@102:     concatenate_iterator() {}
Chris@102: 
Chris@102:     // for begin
Chris@102:     concatenate_iterator(Iterator1 it1, Iterator1 end1,
Chris@102:                          Iterator2 begin2, Iterator2 it2)
Chris@102:         : m_it1(it1), m_end1(end1), m_begin2(begin2), m_it2(it2)
Chris@102:     {}
Chris@102: 
Chris@102:     // for end
Chris@102:     concatenate_iterator(Iterator1 end1, Iterator2 begin2, Iterator2 end2)
Chris@102:         : m_it1(end1), m_end1(end1), m_begin2(begin2), m_it2(end2)
Chris@102:     {}
Chris@102: 
Chris@102:     template
Chris@102:     <
Chris@102:         typename OtherIt1,
Chris@102:         typename OtherIt2,
Chris@102:         typename OtherValue,
Chris@102:         typename OtherReference
Chris@102:     >
Chris@102:     concatenate_iterator(concatenate_iterator
Chris@102:                          <
Chris@102:                              OtherIt1,
Chris@102:                              OtherIt2,
Chris@102:                              OtherValue,
Chris@102:                              OtherReference
Chris@102:                          > const& other)
Chris@102:         : m_it1(other.m_it1)
Chris@102:         , m_end1(other.m_end1)
Chris@102:         , m_begin2(other.m_begin2)
Chris@102:         , m_it2(other.m_it2)
Chris@102:     {
Chris@102:         static const bool are_conv
Chris@102:             = boost::is_convertible<OtherIt1, Iterator1>::value
Chris@102:            && boost::is_convertible<OtherIt2, Iterator2>::value;
Chris@102: 
Chris@102:         BOOST_MPL_ASSERT_MSG((are_conv),
Chris@102:                              NOT_CONVERTIBLE,
Chris@102:                              (types<OtherIt1, OtherIt2>));
Chris@102:     }
Chris@102: 
Chris@102: private:
Chris@102:     friend class boost::iterator_core_access;
Chris@102: 
Chris@102:     template <typename It1, typename It2, typename V, typename R>
Chris@102:     friend class concatenate_iterator;
Chris@102: 
Chris@102:     inline Reference dereference() const
Chris@102:     {
Chris@102:         if ( m_it1 == m_end1 )
Chris@102:         {
Chris@102:             return *m_it2;
Chris@102:         }
Chris@102:         return *m_it1;
Chris@102:     }
Chris@102: 
Chris@102:     template
Chris@102:     <
Chris@102:         typename OtherIt1,
Chris@102:         typename OtherIt2,
Chris@102:         typename OtherValue,
Chris@102:         typename OtherReference
Chris@102:     >
Chris@102:     inline bool equal(concatenate_iterator
Chris@102:                       <
Chris@102:                           OtherIt1,
Chris@102:                           OtherIt2,
Chris@102:                           OtherValue,
Chris@102:                           OtherReference
Chris@102:                       > const& other) const
Chris@102:     {
Chris@102:         return m_it1 == other.m_it1 && m_it2 == other.m_it2;
Chris@102:     }
Chris@102: 
Chris@102:     inline void increment()
Chris@102:     {
Chris@102:         if ( m_it1 == m_end1 )
Chris@102:         {
Chris@102:             ++m_it2;
Chris@102:         }
Chris@102:         else
Chris@102:         {
Chris@102:             ++m_it1;
Chris@102:         }
Chris@102:     }
Chris@102: 
Chris@102:     inline void decrement()
Chris@102:     {
Chris@102:         if ( m_it2 == m_begin2 )
Chris@102:         {
Chris@102:             --m_it1;
Chris@102:         }
Chris@102:         else
Chris@102:         {
Chris@102:             --m_it2;
Chris@102:         }
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: 
Chris@102: }} // namespace boost::geometry
Chris@102: 
Chris@102: #endif // BOOST_GEOMETRY_ITERATORS_CONCATENATE_ITERATOR_HPP