From fa7cd296d37531222363ad592b37265cd474bfec Mon Sep 17 00:00:00 2001
From: Adam Wulkiewicz <adam.wulkiewicz@gmail.com>
Date: Thu, 2 Oct 2014 23:40:53 +0200
Subject: [PATCH] [index] Refactor count rtree visitor.

Remove specialization of count visitor for value_type, don't duplicate the same algorithm in 2 places.
Move Value/Indexable-aware parts into smaller helper struct and specialize it.
---
 .../index/detail/rtree/visitors/count.hpp     | 97 ++++++++-----------
 1 file changed, 39 insertions(+), 58 deletions(-)

diff --git a/include/boost/geometry/index/detail/rtree/visitors/count.hpp b/include/boost/geometry/index/detail/rtree/visitors/count.hpp
index f521944a4..7efd5b702 100644
--- a/include/boost/geometry/index/detail/rtree/visitors/count.hpp
+++ b/include/boost/geometry/index/detail/rtree/visitors/count.hpp
@@ -15,7 +15,37 @@ namespace boost { namespace geometry { namespace index {
 
 namespace detail { namespace rtree { namespace visitors {
 
-template <typename Indexable, typename Value, typename Options, typename Translator, typename Box, typename Allocators>
+template <typename Indexable, typename Value>
+struct count_helper
+{
+    template <typename Translator>
+    static inline typename Translator::result_type indexable(Indexable const& i, Translator const&)
+    {
+        return i;
+    }
+    template <typename Translator>
+    static inline bool equals(Indexable const& i, Value const& v, Translator const& tr)
+    {
+        return geometry::equals(i, tr(v));
+    }
+};
+
+template <typename Value>
+struct count_helper<Value, Value>
+{
+    template <typename Translator>
+    static inline typename Translator::result_type indexable(Value const& v, Translator const& tr)
+    {
+        return tr(v);
+    }
+    template <typename Translator>
+    static inline bool equals(Value const& v1, Value const& v2, Translator const& tr)
+    {
+        return tr.equals(v1, v2);
+    }
+};
+
+template <typename ValueOrIndexable, typename Value, typename Options, typename Translator, typename Box, typename Allocators>
 struct count
     : public rtree::visitor<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag, true>::type
 {
@@ -23,8 +53,10 @@ struct count
     typedef typename rtree::internal_node<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type internal_node;
     typedef typename rtree::leaf<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type leaf;
 
-    inline count(Indexable const& i, Translator const& t)
-        : indexable(i), tr(t), found_count(0)
+    typedef count_helper<ValueOrIndexable, Value> count_help;
+
+    inline count(ValueOrIndexable const& vori, Translator const& t)
+        : value_or_indexable(vori), tr(t), found_count(0)
     {}
 
     inline void operator()(internal_node const& n)
@@ -37,7 +69,8 @@ struct count
              it != elements.end(); ++it)
         {
             if ( geometry::covered_by(
-                    return_ref_or_bounds(indexable),
+                    return_ref_or_bounds(
+                        count_help::indexable(value_or_indexable, tr)),
                     it->first) )
             {
                 rtree::apply_visitor(*this, *it->second);
@@ -55,66 +88,14 @@ struct count
              it != elements.end(); ++it)
         {
             // if value meets predicates
-            if ( geometry::equals(indexable, tr(*it)) )
+            if ( count_help::equals(value_or_indexable, *it, tr) )
             {
                 ++found_count;
             }
         }
     }
 
-    Indexable const& indexable;
-    Translator const& tr;
-    typename Allocators::size_type found_count;
-};
-
-template <typename Value, typename Options, typename Translator, typename Box, typename Allocators>
-struct count<Value, Value, Options, Translator, Box, Allocators>
-    : public rtree::visitor<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag, true>::type
-{
-    typedef typename rtree::node<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type node;
-    typedef typename rtree::internal_node<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type internal_node;
-    typedef typename rtree::leaf<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type leaf;
-
-    inline count(Value const& v, Translator const& t)
-        : value(v), tr(t), found_count(0)
-    {}
-
-    inline void operator()(internal_node const& n)
-    {
-        typedef typename rtree::elements_type<internal_node>::type elements_type;
-        elements_type const& elements = rtree::elements(n);
-
-        // traverse nodes meeting predicates
-        for (typename elements_type::const_iterator it = elements.begin();
-             it != elements.end(); ++it)
-        {
-            if ( geometry::covered_by(
-                    return_ref_or_bounds(tr(value)),
-                    it->first) )
-            {
-                rtree::apply_visitor(*this, *it->second);
-            }
-        }
-    }
-
-    inline void operator()(leaf const& n)
-    {
-        typedef typename rtree::elements_type<leaf>::type elements_type;
-        elements_type const& elements = rtree::elements(n);
-
-        // get all values meeting predicates
-        for (typename elements_type::const_iterator it = elements.begin();
-             it != elements.end(); ++it)
-        {
-            // if value meets predicates
-            if ( tr.equals(value, *it) )
-            {
-                ++found_count;
-            }
-        }
-    }
-
-    Value const& value;
+    ValueOrIndexable const& value_or_indexable;
     Translator const& tr;
     typename Allocators::size_type found_count;
 };