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Diffstat (limited to 'boost/geometry/views/detail/random_access_view.hpp')
| -rw-r--r-- | boost/geometry/views/detail/random_access_view.hpp | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/boost/geometry/views/detail/random_access_view.hpp b/boost/geometry/views/detail/random_access_view.hpp new file mode 100644 index 0000000000..e7c1227554 --- /dev/null +++ b/boost/geometry/views/detail/random_access_view.hpp @@ -0,0 +1,222 @@ +// Boost.Geometry + +// Copyright (c) 2022-2023, Oracle and/or its affiliates. +// Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle +// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle + +// Licensed under the Boost Software License version 1.0. +// http://www.boost.org/users/license.html + +#ifndef BOOST_GEOMETRY_VIEWS_DETAIL_RANDOM_ACCESS_VIEW_HPP +#define BOOST_GEOMETRY_VIEWS_DETAIL_RANDOM_ACCESS_VIEW_HPP + +#include <vector> + +#include <boost/range/begin.hpp> +#include <boost/range/end.hpp> +#include <boost/range/iterator.hpp> +#include <boost/range/size.hpp> + +#include <boost/geometry/algorithms/detail/visit.hpp> +#include <boost/geometry/core/geometry_types.hpp> +#include <boost/geometry/core/tag.hpp> +#include <boost/geometry/core/tags.hpp> +#include <boost/geometry/util/sequence.hpp> +#include <boost/geometry/util/type_traits.hpp> + +namespace boost { namespace geometry +{ + +#ifndef DOXYGEN_NO_DETAIL +namespace detail +{ + + +template <typename Range> +struct is_random_access_range + : std::is_convertible + < + typename boost::iterator_traversal + < + typename boost::range_iterator<Range>::type + >::type, + boost::random_access_traversal_tag + > +{}; + +template <typename Geometry> +struct is_geometry_collection_recursive + : util::bool_constant + < + util::is_geometry_collection + < + typename util::sequence_find_if + < + typename traits::geometry_types<std::remove_const_t<Geometry>>::type, + util::is_geometry_collection + >::type + >::value + > +{}; + +template +< + typename GeometryCollection, + bool IsRandomAccess = is_random_access_range<GeometryCollection>::value, + bool IsRecursive = is_geometry_collection_recursive<GeometryCollection>::value +> +class random_access_view + : public std::vector<typename boost::range_iterator<GeometryCollection>::type> +{ + // NOTE: An alternative would be to implement iterator holding base iterators + // to geometry collections of lower levels to process after the current level + // of bfs traversal is finished. + + using base_t = std::vector<typename boost::range_iterator<GeometryCollection>::type>; + +public: + random_access_view(GeometryCollection & geometry) + { + this->reserve(boost::size(geometry)); + detail::visit_breadth_first_impl<true>::apply([&](auto&&, auto iter) + { + this->push_back(iter); + return true; + }, geometry); + } +}; + +template <typename GeometryCollection> +class random_access_view<GeometryCollection, true, false> +{ +public: + using iterator = typename boost::range_iterator<GeometryCollection>::type; + using const_iterator = typename boost::range_const_iterator<GeometryCollection>::type; + + random_access_view(GeometryCollection & geometry) + : m_begin(boost::begin(geometry)) + , m_end(boost::end(geometry)) + {} + + iterator begin() { return m_begin; } + iterator end() { return m_end; } + const_iterator begin() const { return m_begin; } + const_iterator end() const { return m_end; } + +private: + iterator m_begin, m_end; +}; + + +template <typename GeometryCollection> +struct random_access_view_iter_visit +{ + template <typename Function, typename Iterator> + static void apply(Function && function, Iterator iterator) + { + geometry::traits::iter_visit + < + std::remove_const_t<GeometryCollection> + >::apply(std::forward<Function>(function), *iterator); + } +}; + + +template <typename ...Ts> +struct remove_geometry_collections_pack +{ + using type = util::type_sequence<>; +}; + +template <typename T, typename ...Ts> +struct remove_geometry_collections_pack<T, Ts...> +{ + using next_sequence = typename remove_geometry_collections_pack<Ts...>::type; + using type = std::conditional_t + < + util::is_geometry_collection<T>::value, + next_sequence, + typename util::sequence_merge<util::type_sequence<T>, next_sequence>::type + >; +}; + +template <typename Types> +struct remove_geometry_collections; + +template <typename ...Ts> +struct remove_geometry_collections<util::type_sequence<Ts...>> + : remove_geometry_collections_pack<Ts...> +{}; + + +} // namespace detail +#endif // DOXYGEN_NO_DETAIL + + +#ifndef DOXYGEN_NO_TRAITS_SPECIALIZATIONS +namespace traits +{ + +template<typename GeometryCollection, bool IsRandomAccess, bool IsRecursive> +struct tag<geometry::detail::random_access_view<GeometryCollection, IsRandomAccess, IsRecursive>> +{ + using type = geometry_collection_tag; +}; + + +template <typename GeometryCollection> +struct iter_visit<geometry::detail::random_access_view<GeometryCollection, false, false>> + : geometry::detail::random_access_view_iter_visit<GeometryCollection> +{}; + +template <typename GeometryCollection> +struct iter_visit<geometry::detail::random_access_view<GeometryCollection, true, true>> + : geometry::detail::random_access_view_iter_visit<GeometryCollection> +{}; + +template <typename GeometryCollection> +struct iter_visit<geometry::detail::random_access_view<GeometryCollection, false, true>> + : geometry::detail::random_access_view_iter_visit<GeometryCollection> +{}; + +template <typename GeometryCollection> +struct iter_visit<geometry::detail::random_access_view<GeometryCollection, true, false>> +{ + template <typename Function, typename Iterator> + static void apply(Function && function, Iterator iterator) + { + geometry::traits::iter_visit + < + std::remove_const_t<GeometryCollection> + >::apply(std::forward<Function>(function), iterator); + } +}; + + +template <typename GeometryCollection, bool IsRandomAccess> +struct geometry_types<geometry::detail::random_access_view<GeometryCollection, IsRandomAccess, false>> + : traits::geometry_types + < + std::remove_const_t<GeometryCollection> + > +{}; + +template <typename GeometryCollection, bool IsRandomAccess> +struct geometry_types<geometry::detail::random_access_view<GeometryCollection, IsRandomAccess, true>> + : geometry::detail::remove_geometry_collections + < + typename traits::geometry_types + < + std::remove_const_t<GeometryCollection> + >::type + > +{}; + +} // namespace traits +#endif // DOXYGEN_NO_TRAITS_SPECIALIZATIONS + + +}} // namespace boost::geometry + + +#endif // BOOST_GEOMETRY_VIEWS_DETAIL_RANDOM_ACCESS_VIEW_HPP |