Various minor improvements

include/boost/geometry/algorithms/assign.hpp

@@ -216,7 +216,7 @@ template <typename Geometry1, typename Geometry2>
 struct assign
 {
     static inline void
-    apply(Geometry1& geometry1, const Geometry2& geometry2)
+    apply(Geometry1& geometry1, Geometry2 const& geometry2)
     {
         concepts::check<Geometry1>();
         concepts::check<Geometry2 const>();

include/boost/geometry/algorithms/correct_closure.hpp

@@ -26,6 +26,7 @@
 #include <boost/geometry/geometries/concepts/check.hpp>
 
 #include <boost/geometry/util/range.hpp>
+#include <boost/range/size.hpp>
 
 namespace boost { namespace geometry
 {

include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp

@@ -698,7 +698,7 @@ struct buffered_piece_collection
         BOOST_GEOMETRY_ASSERT(pc.offsetted_count >= 0);
     }
 
-    inline void add_piece_point(piece& pc, const point_type& point, bool add_to_original)
+    inline void add_piece_point(piece& pc, point_type const& point, bool add_to_original)
     {
         if (add_to_original && pc.type != strategy::buffer::buffered_concave)
         {

include/boost/geometry/algorithms/detail/buffer/line_line_intersection.hpp

@@ -77,7 +77,7 @@ struct line_line_intersection
         // | pa pa |
         // | qb qb |
         auto const denominator_pq = determinant<line, &line::a, &line::b>(p, q);
-        constexpr decltype(denominator_pq) const zero = 0;
+        static decltype(denominator_pq) const zero = 0;
 
         if (equidistant)
         {

include/boost/geometry/algorithms/detail/buffer/piece_border.hpp

@@ -18,6 +18,7 @@
 #include <array>
 
 #include <boost/core/addressof.hpp>
+#include <boost/range/size.hpp>
 
 #include <boost/geometry/core/assert.hpp>
 #include <boost/geometry/core/config.hpp>

include/boost/geometry/algorithms/detail/buffer/turn_in_original_visitor.hpp

@@ -16,8 +16,9 @@
 
 
 #include <boost/core/ignore_unused.hpp>
-#include <boost/geometry/core/coordinate_type.hpp>
+#include <boost/range/size.hpp>
 
+#include <boost/geometry/core/coordinate_type.hpp>
 #include <boost/geometry/algorithms/detail/buffer/buffer_policies.hpp>
 #include <boost/geometry/algorithms/detail/disjoint/interface.hpp>
 #include <boost/geometry/algorithms/expand.hpp>

include/boost/geometry/algorithms/detail/calculate_point_order.hpp

@@ -14,6 +14,8 @@
 
 #include <vector>
 
+#include <boost/range/size.hpp>
+
 #include <boost/geometry/algorithms/area.hpp>
 #include <boost/geometry/core/point_order.hpp>
 #include <boost/geometry/core/radian_access.hpp>

include/boost/geometry/algorithms/detail/closest_feature/point_to_range.hpp

@@ -14,7 +14,6 @@
 
 #include <boost/range/begin.hpp>
 #include <boost/range/end.hpp>
-#include <boost/range/size.hpp>
 
 #include <boost/geometry/core/assert.hpp>
 #include <boost/geometry/core/closure.hpp>

include/boost/geometry/algorithms/detail/closest_points/multipoint_to_geometry.hpp

@@ -12,6 +12,8 @@
 
 #include <iterator>
 
+#include <boost/range/size.hpp>
+
 #include <boost/geometry/algorithms/covered_by.hpp>
 #include <boost/geometry/algorithms/detail/closest_points/range_to_geometry_rtree.hpp>
 #include <boost/geometry/algorithms/detail/closest_points/utilities.hpp>

include/boost/geometry/algorithms/detail/convex_hull/graham_andrew.hpp

@@ -23,6 +23,8 @@
 #include <algorithm>
 #include <vector>
 
+#include <boost/range/size.hpp>
+
 #include <boost/geometry/algorithms/detail/for_each_range.hpp>
 #include <boost/geometry/core/assert.hpp>
 #include <boost/geometry/core/closure.hpp>

include/boost/geometry/algorithms/detail/convex_hull/interface.hpp

@@ -24,6 +24,8 @@
 
 #include <array>
 
+#include <boost/range/size.hpp>
+
 #include <boost/geometry/algorithms/detail/assign_box_corners.hpp>
 #include <boost/geometry/algorithms/detail/convex_hull/graham_andrew.hpp>
 #include <boost/geometry/algorithms/detail/equals/point_point.hpp>

include/boost/geometry/algorithms/detail/disjoint/linear_segment_or_box.hpp

@@ -22,6 +22,8 @@
 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_DISJOINT_LINEAR_SEGMENT_OR_BOX_HPP
 
 
+#include <boost/range/size.hpp>
+
 #include <boost/geometry/algorithms/detail/disjoint/multirange_geometry.hpp>
 #include <boost/geometry/algorithms/dispatch/disjoint.hpp>
 #include <boost/geometry/algorithms/not_implemented.hpp>

include/boost/geometry/algorithms/detail/distance/geometry_collection.hpp

@@ -12,6 +12,8 @@
 
 #include <vector>
 
+#include <boost/range/size.hpp>
+
 #include <boost/geometry/algorithms/dispatch/distance.hpp>
 #include <boost/geometry/algorithms/detail/visit.hpp>
 #include <boost/geometry/core/assert.hpp>

include/boost/geometry/algorithms/detail/equals/collect_vectors.hpp

@@ -21,6 +21,7 @@
 
 
 #include <boost/numeric/conversion/cast.hpp>
+#include <boost/range/size.hpp>
 
 #include <boost/geometry/algorithms/detail/normalize.hpp>
 #include <boost/geometry/algorithms/not_implemented.hpp>

include/boost/geometry/algorithms/detail/intersection/gc.hpp

@@ -12,6 +12,8 @@
 
 #include <tuple>
 
+#include <boost/range/size.hpp>
+
 #include <boost/geometry/algorithms/detail/gc_make_rtree.hpp>
 #include <boost/geometry/algorithms/detail/intersection/interface.hpp>
 #include <boost/geometry/views/detail/geometry_collection_view.hpp>

include/boost/geometry/algorithms/detail/is_valid/multipolygon.hpp

@@ -20,7 +20,6 @@
 #include <boost/iterator/filter_iterator.hpp>
 #include <boost/range/begin.hpp>
 #include <boost/range/end.hpp>
-#include <boost/range/size.hpp>
 #include <boost/range/value_type.hpp>
 
 #include <boost/geometry/core/exterior_ring.hpp>

include/boost/geometry/algorithms/detail/is_valid/ring.hpp

@@ -15,6 +15,8 @@
 
 #include <deque>
 
+#include <boost/range/size.hpp>
+
 #include <boost/core/ignore_unused.hpp>
 
 #include <boost/geometry/core/closure.hpp>
@@ -38,12 +40,11 @@
 #include <boost/geometry/algorithms/detail/is_valid/has_valid_self_turns.hpp>
 #include <boost/geometry/algorithms/dispatch/is_valid.hpp>
 
-// TEMP - with UmberllaStrategy this will be not needed
+// TEMP - with UmbrellaStrategy this will be not needed
 #include <boost/geometry/strategy/area.hpp>
 #include <boost/geometry/strategies/area/services.hpp>
 // TODO: use point_order instead of area
 
-
 #ifdef BOOST_GEOMETRY_TEST_DEBUG
 #include <boost/geometry/io/dsv/write.hpp>
 #endif

include/boost/geometry/algorithms/detail/overlay/append_no_dups_or_spikes.hpp

@@ -100,7 +100,7 @@ inline void append_no_dups_or_spikes(Range& range, Point const& point,
         return;
     }
 
-    auto append = [](auto& r, const auto& p)
+    auto append = [](auto& r, auto const& p)
     {
         using point_t = typename boost::range_value<Range>::type;
         point_t rp;

include/boost/geometry/algorithms/detail/overlay/approximately_equals.hpp

@@ -22,11 +22,26 @@ namespace detail { namespace overlay
 {
 
 // Value for approximately_equals used by get_cluster and sort_by_side
+// This is an "epsilon_multiplier" and, therefore, multiplied the epsilon
+// belonging to the used floating point type with this value.
 template <typename T>
-struct common_approximately_equals_epsilon
+struct common_approximately_equals_epsilon_multiplier
 {
     static T value()
     {
+        // The value is (a bit) arbitrary. For sort_by_side it should be large
+        // enough to not take a point which is too close by, to calculate the
+        // side value correctly. For get_cluster it is arbitrary as well, points
+        // close to each other should form a cluster, which is also important
+        // for subsequent side calculations. Points too far apart should not be
+        // clustered.
+        //
+        // The value of 100 is currently considered as a sweet spot.
+        // If the value changes (as of 2023-09-13):
+        //   10: too small, failing unit test(s):
+        //     - union: issue_1108
+        //   50: this would be fine, no tests failing
+        //   1000: this would be fine, no tests failing
         return T(100);
     }
 };

include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp

@@ -362,7 +362,7 @@ inline void assign_parents(Geometry1 const& geometry1,
             }
             else if (info.parent.source_index >= 0)
             {
-                const ring_info_type& parent = ring_map[info.parent];
+                ring_info_type const& parent = ring_map[info.parent];
                 bool const pos = math::larger(info.get_area(), 0);
                 bool const parent_pos = math::larger(parent.area, 0);
 

include/boost/geometry/algorithms/detail/overlay/colocate_clusters.hpp

@@ -62,14 +62,14 @@ struct cluster_colocator<Point, CoordinateType, geometry::cartesian_tag, false>
     {
         CoordinateType centroid_0 = 0;
         CoordinateType centroid_1 = 0;
-        for (const auto& index : indices)
+        for (auto const& index : indices)
         {
             centroid_0 += geometry::get<0>(turns[index].point);
             centroid_1 += geometry::get<1>(turns[index].point);
         }
         centroid_0 /= indices.size();
         centroid_1 /= indices.size();
-        for (const auto& index : indices)
+        for (auto const& index : indices)
         {
             geometry::set<0>(turns[index].point, centroid_0);
             geometry::set<1>(turns[index].point, centroid_1);
@@ -86,14 +86,14 @@ inline void colocate_clusters(Clusters const& clusters, Turns& turns)
 {
     for (auto const& pair : clusters)
     {
-        auto const& indices = pair.second.turn_indices;
-        if (indices.size() < 2)
+        auto const& turn_indices = pair.second.turn_indices;
+        if (turn_indices.size() < 2)
         {
             // Defensive check
             continue;
         }
-        using point_t = decltype(turns[*indices.begin()].point);
-        cluster_colocator<point_t>::apply(indices, turns);
+        using point_t = decltype(turns[*turn_indices.begin()].point);
+        cluster_colocator<point_t>::apply(turn_indices, turns);
     }
 }
 

include/boost/geometry/algorithms/detail/overlay/discard_duplicate_turns.hpp

@@ -114,7 +114,7 @@ inline void discard_duplicate_start_turns(Turns& turns,
     {
         if (turn.method == method_start)
         {
-            for (const auto& op : turn.operations)
+            for (auto const& op : turn.operations)
             {
                 start_turns_per_segment[adapt_id(op.seg_id)].push_back(index);
             }
@@ -130,7 +130,7 @@ inline void discard_duplicate_start_turns(Turns& turns,
         // Also avoid comparing "start" with itself.
         if (turn.method != method_crosses && turn.method != method_start)
         {
-            for (const auto& op : turn.operations)
+            for (auto const& op : turn.operations)
             {
                 auto it = start_turns_per_segment.find(adapt_id(op.seg_id));
                 if (it != start_turns_per_segment.end())

include/boost/geometry/algorithms/detail/overlay/get_clusters.hpp

@@ -37,18 +37,22 @@ struct sweep_equal_policy
 {
 
 public:
-    // Returns true if point are considered equal (within an epsilon)
+    // Returns true if point are considered equal
     template <typename P>
     static inline bool equals(P const& p1, P const& p2)
     {
         using coor_t = typename coordinate_type<P>::type;
-        return approximately_equals(p1, p2, common_approximately_equals_epsilon<coor_t>::value());
+        static auto const tolerance
+            = common_approximately_equals_epsilon_multiplier<coor_t>::value();
+        return approximately_equals(p1, p2, tolerance);
     }
 
     template <typename T>
     static inline bool exceeds(T value)
     {
-        T const limit = T(1) / common_approximately_equals_epsilon<T>::value();
+        static auto const tolerance
+            = common_approximately_equals_epsilon_multiplier<T>::value();
+        T const limit = T(1) / tolerance;
         return value > limit;
     }
 };

include/boost/geometry/algorithms/detail/overlay/get_distance_measure.hpp

@@ -78,7 +78,7 @@ struct get_distance_measure<CalculationType, spherical_tag>
     static result_type apply(SegmentPoint const& , SegmentPoint const& ,
                              Point const& )
     {
-        const result_type result;
+        result_type const result;
         return result;
     }
 };
@@ -125,7 +125,7 @@ inline auto get_distance_measure(SegmentPoint const& p1, SegmentPoint const& p2,
     // Verify equality, without using a tolerance
     // (so don't use equals or equals_point_point)
     // because it is about very tiny differences.
-    auto identical = [](const auto& point1, const auto& point2)
+    auto identical = [](auto const& point1, auto const& point2)
     {
         return geometry::get<0>(point1) == geometry::get<0>(point2)
             && geometry::get<1>(point1) == geometry::get<1>(point2);

include/boost/geometry/algorithms/detail/overlay/get_turn_info.hpp

@@ -589,7 +589,7 @@ struct touch : public base_turn_handler
         // >----->P     qj is LEFT of P1 and pi is LEFT of Q2
         //              (the other way round is also possible)
 
-        auto has_distance = [&](const auto& r1, const auto& r2) -> bool
+        auto has_distance = [&](auto const& r1, auto const& r2) -> bool
         {
             auto const d1 = get_distance_measure(r1.at(0), r1.at(1), r2.at(1), umbrella_strategy);
             auto const d2 = get_distance_measure(r2.at(1), r2.at(2), r1.at(0), umbrella_strategy);

include/boost/geometry/algorithms/detail/overlay/get_turn_info_la.hpp

@@ -696,7 +696,7 @@ struct get_turn_info_linear_areal
         namespace ov = overlay;
         typedef ov::get_turn_info_for_endpoint<EnableFirst, EnableLast> get_info_e;
 
-        const std::size_t ip_count = inters.i_info().count;
+        std::size_t const ip_count = inters.i_info().count;
         // no intersection points
         if (ip_count == 0)
         {

include/boost/geometry/algorithms/detail/overlay/handle_colocations.hpp

@@ -296,7 +296,7 @@ inline void assign_cluster_ids(Turns& turns, Clusters const& clusters)
     }
     for (auto const& kv : clusters)
     {
-        for (const auto& index : kv.second.turn_indices)
+        for (auto const& index : kv.second.turn_indices)
         {
             turns[index].cluster_id = kv.first;
         }

include/boost/geometry/algorithms/detail/overlay/handle_self_turns.hpp

@@ -128,7 +128,7 @@ private :
     template <typename Turns, typename Clusters>
     static inline
     bool is_self_cluster(signed_size_type cluster_id,
-            const Turns& turns, Clusters const& clusters)
+            Turns const& turns, Clusters const& clusters)
     {
         auto cit = clusters.find(cluster_id);
         if (cit == clusters.end())