diff --git a/include/mapnik/rule.hpp b/include/mapnik/rule.hpp
index eb5a02c7e..c4aa79209 100644
--- a/include/mapnik/rule.hpp
+++ b/include/mapnik/rule.hpp
@@ -39,6 +39,7 @@
 #include <mapnik/expression_string.hpp>
 
 // boost
+#include <boost/concept_check.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/make_shared.hpp>
 #include <boost/variant.hpp>
@@ -125,6 +126,8 @@ typedef boost::variant<point_symbolizer,
                        glyph_symbolizer> symbolizer;
     
         
+
+
 class rule
 {    
 public:
@@ -138,6 +141,104 @@ private:
     expression_ptr filter_;
     bool else_filter_;
     bool also_filter_;
+
+    struct deepcopy_symbolizer : public boost::static_visitor<>
+    {
+        
+        void operator () (markers_symbolizer & sym) const
+        {
+            copy_path_ptr(sym);
+        }
+
+        void operator () (point_symbolizer & sym) const
+        {
+            copy_path_ptr(sym);
+        }
+
+        void operator () (polygon_pattern_symbolizer & sym) const
+        {
+            copy_path_ptr(sym);
+        }
+        
+        void operator () (line_pattern_symbolizer & sym) const
+        {
+            copy_path_ptr(sym);
+        }
+        
+        void operator () (raster_symbolizer & sym) const
+        {
+            raster_colorizer_ptr old_colorizer = sym.get_colorizer();
+            raster_colorizer_ptr new_colorizer = raster_colorizer_ptr();            
+            new_colorizer->set_stops(old_colorizer->get_stops());
+            new_colorizer->set_default_mode(old_colorizer->get_default_mode());
+            new_colorizer->set_default_color(old_colorizer->get_default_color());
+            new_colorizer->set_epsilon(old_colorizer->get_epsilon());            
+            sym.set_colorizer(new_colorizer);
+        }
+
+        void operator () (text_symbolizer & sym) const
+        {
+            copy_text_ptr(sym);
+        }
+        
+        void operator () (shield_symbolizer & sym) const
+        {
+            copy_path_ptr(sym);
+            copy_text_ptr(sym);
+        }
+
+        void operator () (building_symbolizer & sym) const
+        {
+            copy_height_ptr(sym);
+        }
+        
+        
+        template <typename T> void operator () (T &sym) const
+        {
+            boost::ignore_unused_variable_warning(sym);
+        }
+        
+    private:
+        template <class T>
+        void copy_path_ptr(T & sym) const
+        {
+            std::string path = path_processor_type::to_string(*sym.get_filename());
+            sym.set_filename( parse_path(path) );
+        }
+        
+        template <class T>
+        void copy_text_ptr(T & sym) const
+        {
+            std::string name = to_expression_string(*sym.get_name());
+            sym.set_name( parse_expression(name) );
+            
+            // FIXME - orientation doesn't appear to be initialized in constructor?
+            //std::string orientation = to_expression_string(*sym->get_orientation());
+            //sym->set_orientation( parse_expression(orientation) );
+            
+            float text_size = sym.get_text_size();
+            position displace = sym.get_displacement();
+            vertical_alignment_e valign = sym.get_vertical_alignment();
+            horizontal_alignment_e halign = sym.get_horizontal_alignment();
+            justify_alignment_e jalign = sym.get_justify_alignment();
+            
+            text_placements_ptr placements = text_placements_ptr(boost::make_shared<text_placements_dummy>());
+            sym.set_placement_options( placements );     
+            sym.set_text_size(text_size);
+            sym.set_displacement(displace);
+            sym.set_vertical_alignment(valign);
+            sym.set_horizontal_alignment(halign);
+            sym.set_justify_alignment(jalign);
+        }
+
+        template <class T>
+        void copy_height_ptr(T & sym) const
+        {
+            std::string height_expr = to_expression_string(sym.height());
+            sym.set_height(parse_expression(height_expr,"utf8"));
+        }
+    };
+    
 public:
     rule()
         : name_(),
@@ -169,48 +270,18 @@ public:
           also_filter_(rhs.also_filter_) 
     {
         if (deep_copy) {
-            //std::string expr = to_expression_string(rhs.filter_);
-            //filter_ = parse_expression(expr,"utf8");
+            
+            std::string expr = to_expression_string(rhs.filter_);
+            filter_ = parse_expression(expr,"utf8");
             
             symbolizers::iterator it  = syms_.begin(),
                                   end = syms_.end();
             
             // FIXME - metawriter_ptr?
             
-            for(; it != end; ++it) {
-                
-                /*if (polygon_symbolizer *sym = boost::get<polygon_symbolizer>(&(*it))) {
-                    // no shared pointers
-                } else if (line_symbolizer *sym = boost::get<line_symbolizer>(&(*it))) {
-                    // no shared pointers
-                } else if (building_symbolizer *sym = boost::get<building_symbolizer>(&(*it))) {
-                    // no shared pointers
-                }*/
-                
-                if (markers_symbolizer *sym = boost::get<markers_symbolizer>(&(*it))) {
-                    copy_path_ptr(sym);
-                } else if (point_symbolizer *sym = boost::get<point_symbolizer>(&(*it))) {
-                    copy_path_ptr(sym);
-                } else if (polygon_pattern_symbolizer *sym = boost::get<polygon_pattern_symbolizer>(&(*it))) {
-                    copy_path_ptr(sym);
-                } else if (line_pattern_symbolizer *sym = boost::get<line_pattern_symbolizer>(&(*it))) {
-                    copy_path_ptr(sym);
-                } else if (raster_symbolizer *sym = boost::get<raster_symbolizer>(&(*it))) {
-                    raster_colorizer_ptr old_colorizer = sym->get_colorizer(),
-                                         new_colorizer = raster_colorizer_ptr();
-                    
-                    new_colorizer->set_stops( old_colorizer->get_stops());
-                    new_colorizer->set_default_mode( old_colorizer->get_default_mode() );
-                    new_colorizer->set_default_color( old_colorizer->get_default_color() );
-                    new_colorizer->set_epsilon( old_colorizer->get_epsilon() );
-                    
-                    sym->set_colorizer(new_colorizer);
-                } else if (shield_symbolizer *sym = boost::get<shield_symbolizer>(&(*it))) {
-                    copy_path_ptr(sym);
-                    copy_text_ptr(sym);
-                } else if (text_symbolizer *sym = boost::get<text_symbolizer>(&(*it))) {
-                    copy_text_ptr(sym);
-                }
+            for(; it != end; ++it) 
+            {                
+                boost::apply_visitor(deepcopy_symbolizer(),*it);                
             }
         }
     }
@@ -340,40 +411,7 @@ private:
         filter_=rhs.filter_;
         else_filter_=rhs.else_filter_;
         also_filter_=rhs.also_filter_;
-    }
-    
-    template <class T>
-    void copy_path_ptr(T* sym)
-    {
-        std::string path = path_processor_type::to_string(*sym->get_filename());
-        sym->set_filename( parse_path(path) );
-    }
-    
-    template <class T>
-    void copy_text_ptr(T* sym)
-    {
-        std::string name = to_expression_string(*sym->get_name());
-        sym->set_name( parse_expression(name) );
-        
-        // FIXME - orientation doesn't appear to be initialized in constructor?
-        //std::string orientation = to_expression_string(*sym->get_orientation());
-        //sym->set_orientation( parse_expression(orientation) );
-        
-        float text_size = sym->get_text_size();
-        position displace = sym->get_displacement();
-        vertical_alignment_e valign = sym->get_vertical_alignment();
-        horizontal_alignment_e halign = sym->get_horizontal_alignment();
-        justify_alignment_e jalign = sym->get_justify_alignment();
-        
-        text_placements_ptr placements = text_placements_ptr(boost::make_shared<text_placements_dummy>());
-        sym->set_placement_options( placements );
-        
-        sym->set_text_size(text_size);
-        sym->set_displacement(displace);
-        sym->set_vertical_alignment(valign);
-        sym->set_horizontal_alignment(halign);
-        sym->set_justify_alignment(jalign);
-    }
+    }    
 };
 
 }