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Diffstat (limited to 'boost/geometry/iterators/flatten_iterator.hpp')
| -rw-r--r-- | boost/geometry/iterators/flatten_iterator.hpp | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/boost/geometry/iterators/flatten_iterator.hpp b/boost/geometry/iterators/flatten_iterator.hpp new file mode 100644 index 0000000000..078079dc2c --- /dev/null +++ b/boost/geometry/iterators/flatten_iterator.hpp @@ -0,0 +1,259 @@ +// 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_FLATTEN_ITERATOR_HPP +#define BOOST_GEOMETRY_ITERATORS_FLATTEN_ITERATOR_HPP + +#include <boost/assert.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> + + +namespace boost { namespace geometry +{ + + + +template +< + typename OuterIterator, + typename InnerIterator, + typename Value, + typename AccessInnerBegin, + typename AccessInnerEnd, + typename Reference = Value& +> +class flatten_iterator + : public boost::iterator_facade + < + flatten_iterator + < + OuterIterator, + InnerIterator, + Value, + AccessInnerBegin, + AccessInnerEnd, + Reference + >, + Value, + boost::bidirectional_traversal_tag, + Reference + > +{ +private: + OuterIterator m_outer_it, m_outer_end; + InnerIterator m_inner_it; + +public: + typedef OuterIterator outer_iterator_type; + typedef InnerIterator inner_iterator_type; + + // default constructor + flatten_iterator() {} + + // for begin + flatten_iterator(OuterIterator outer_it, OuterIterator outer_end) + : m_outer_it(outer_it), m_outer_end(outer_end) + { + advance_through_empty(); + } + + // for end + flatten_iterator(OuterIterator outer_end) + : m_outer_it(outer_end), m_outer_end(outer_end) + {} + + template + < + typename OtherOuterIterator, typename OtherInnerIterator, + typename OtherValue, + typename OtherAccessInnerBegin, typename OtherAccessInnerEnd, + typename OtherReference + > + flatten_iterator(flatten_iterator + < + OtherOuterIterator, + OtherInnerIterator, + OtherValue, + OtherAccessInnerBegin, + OtherAccessInnerEnd, + OtherReference + > const& other) + : m_outer_it(other.m_outer_it), + m_outer_end(other.m_outer_end), + m_inner_it(other.m_inner_it) + { + static const bool are_conv + = boost::is_convertible + < + OtherOuterIterator, OuterIterator + >::value + && boost::is_convertible + < + OtherInnerIterator, InnerIterator + >::value; + + BOOST_MPL_ASSERT_MSG((are_conv), + NOT_CONVERTIBLE, + (types<OtherOuterIterator, OtherInnerIterator>)); + } + + template + < + typename OtherOuterIterator, + typename OtherInnerIterator, + typename OtherValue, + typename OtherAccessInnerBegin, + typename OtherAccessInnerEnd, + typename OtherReference + > + flatten_iterator operator=(flatten_iterator + < + OtherOuterIterator, + OtherInnerIterator, + OtherValue, + OtherAccessInnerBegin, + OtherAccessInnerEnd, + OtherReference + > const& other) + { + static const bool are_conv + = boost::is_convertible + < + OtherOuterIterator, OuterIterator + >::value + && boost::is_convertible + < + OtherInnerIterator, InnerIterator + >::value; + + BOOST_MPL_ASSERT_MSG((are_conv), + NOT_CONVERTIBLE, + (types<OtherOuterIterator, OtherInnerIterator>)); + + m_outer_it = other.m_outer_it; + m_outer_end = other.m_outer_end; + m_inner_it = other.m_inner_it; + return *this; + } + +private: + friend class boost::iterator_core_access; + + template + < + typename Outer, + typename Inner, + typename V, + typename InnerBegin, + typename InnerEnd, + typename R + > + friend class flatten_iterator; + + static inline bool empty(OuterIterator outer_it) + { + return + AccessInnerBegin::apply(*outer_it) == AccessInnerEnd::apply(*outer_it); + } + + inline void advance_through_empty() + { + while ( m_outer_it != m_outer_end && empty(m_outer_it) ) + { + ++m_outer_it; + } + + if ( m_outer_it != m_outer_end ) + { + m_inner_it = AccessInnerBegin::apply(*m_outer_it); + } + } + + inline Reference dereference() const + { + BOOST_ASSERT( m_outer_it != m_outer_end ); + BOOST_ASSERT( m_inner_it != AccessInnerEnd::apply(*m_outer_it) ); + return *m_inner_it; + } + + + template + < + typename OtherOuterIterator, + typename OtherInnerIterator, + typename OtherValue, + typename OtherAccessInnerBegin, + typename OtherAccessInnerEnd, + typename OtherReference + > + inline bool equal(flatten_iterator + < + OtherOuterIterator, + OtherInnerIterator, + OtherValue, + OtherAccessInnerBegin, + OtherAccessInnerEnd, + OtherReference + > const& other) const + { + if ( m_outer_it != other.m_outer_it ) + { + return false; + } + + if ( m_outer_it == m_outer_end ) + { + return true; + } + + return m_inner_it == other.m_inner_it; + } + + inline void increment() + { + BOOST_ASSERT( m_outer_it != m_outer_end ); + BOOST_ASSERT( m_inner_it != AccessInnerEnd::apply(*m_outer_it) ); + + ++m_inner_it; + if ( m_inner_it == AccessInnerEnd::apply(*m_outer_it) ) + { + ++m_outer_it; + advance_through_empty(); + } + } + + inline void decrement() + { + if ( m_outer_it == m_outer_end + || m_inner_it == AccessInnerBegin::apply(*m_outer_it) ) + { + do + { + --m_outer_it; + } + while ( empty(m_outer_it) ); + m_inner_it = --AccessInnerEnd::apply(*m_outer_it); + } + else + { + --m_inner_it; + } + } +}; + + + +}} // namespace boost::geometry + + +#endif // BOOST_GEOMETRY_ITERATORS_FLATTEN_ITERATOR_HPP |