From 258183d7aa4ea54a545a8de780eaff82ee38cb3d Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Wed, 27 Apr 2016 14:18:47 +0200
Subject: [PATCH] [traverse] move counting open spaces to sort_by_side
 structure

---
 .../detail/overlay/sort_by_side.hpp           | 29 +++++++++++++++++++
 .../algorithms/detail/overlay/traversal.hpp   | 24 ++-------------
 2 files changed, 31 insertions(+), 22 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/overlay/sort_by_side.hpp b/include/boost/geometry/algorithms/detail/overlay/sort_by_side.hpp
index 894cddab8..1227e09b3 100644
--- a/include/boost/geometry/algorithms/detail/overlay/sort_by_side.hpp
+++ b/include/boost/geometry/algorithms/detail/overlay/sort_by_side.hpp
@@ -330,6 +330,35 @@ struct side_sorter
         }
     }
 
+    //! Check how many open spaces there are
+    template <typename Turns>
+    std::size_t open_count(Turns const& turns) const
+    {
+        typedef typename boost::range_value<Turns>::type turn_type;
+        typedef typename turn_type::turn_operation_type turn_operation_type;
+
+        std::size_t result = 0;
+        std::size_t last_rank = 0;
+        for (std::size_t i = 0; i < m_ranked_points.size(); i++)
+        {
+            rp const& ranked_point = m_ranked_points[i];
+
+            if (ranked_point.main_rank > last_rank
+                && ranked_point.index == sort_by_side::index_to)
+            {
+                turn_type const& ranked_turn = turns[ranked_point.turn_index];
+                turn_operation_type const& ranked_op = ranked_turn.operations[ranked_point.op_index];
+                if (ranked_op.enriched.count_left == 0
+                     && ranked_op.enriched.count_right > 0)
+                {
+                    result++;
+                    last_rank = ranked_point.main_rank;
+                }
+            }
+        }
+        return result;
+    }
+
 //protected :
 
     typedef std::vector<rp> container_type;
diff --git a/include/boost/geometry/algorithms/detail/overlay/traversal.hpp b/include/boost/geometry/algorithms/detail/overlay/traversal.hpp
index 3f8f73f2f..51f014cd9 100644
--- a/include/boost/geometry/algorithms/detail/overlay/traversal.hpp
+++ b/include/boost/geometry/algorithms/detail/overlay/traversal.hpp
@@ -493,30 +493,10 @@ struct traversal
 
         sbs.apply(turn.point);
 
-        int open_count = 0;
+        std::size_t open_count = 0;
         if (is_union) //  && ! cinfo.switch_source)
         {
-            // Check how many open spaces there are.
-            // TODO: might be moved to sbs itself, though it also uses turns
-
-            std::size_t last_rank = 0;
-            for (std::size_t i = 0; i < sbs.m_ranked_points.size(); i++)
-            {
-                typename sbs_type::rp const& ranked_point = sbs.m_ranked_points[i];
-
-                if (ranked_point.main_rank > last_rank
-                    && ranked_point.index == sort_by_side::index_to)
-                {
-                    turn_type const& ranked_turn = m_turns[ranked_point.turn_index];
-                    turn_operation_type const& ranked_op = ranked_turn.operations[ranked_point.op_index];
-                    if (ranked_op.enriched.count_left == 0
-                         && ranked_op.enriched.count_right > 0)
-                    {
-                        open_count++;
-                        last_rank = ranked_point.main_rank;
-                    }
-                }
-            }
+            open_count = sbs.open_count(m_turns);
         }
 
         is_touching = open_count > 1;