diff --git a/include/mapnik/distance.hpp b/include/mapnik/distance.hpp
index b1f21121d..5485aa11b 100644
--- a/include/mapnik/distance.hpp
+++ b/include/mapnik/distance.hpp
@@ -29,7 +29,7 @@
 
 namespace mapnik
 {
-    class ellipsoid;
+    struct ellipsoid;
     
     // great-circle distance 
     
diff --git a/include/mapnik/map.hpp b/include/mapnik/map.hpp
index 089b88a6a..0b721399c 100644
--- a/include/mapnik/map.hpp
+++ b/include/mapnik/map.hpp
@@ -314,8 +314,8 @@ namespace mapnik
         featureset_ptr query_map_point(unsigned index, double x, double y) const;
         ~Map();
 
-        void setAspectFixMode(aspect_fix_mode afm) { aspectFixMode_ = afm; }
-        bool getAspectFixMode() { return aspectFixMode_; }
+        inline void setAspectFixMode(aspect_fix_mode afm) { aspectFixMode_ = afm; }
+        inline int getAspectFixMode() { return aspectFixMode_; }
 
     private:
         void fixAspectRatio();
diff --git a/include/mapnik/value.hpp b/include/mapnik/value.hpp
index 5717ce221..082bd9dfb 100644
--- a/include/mapnik/value.hpp
+++ b/include/mapnik/value.hpp
@@ -96,13 +96,13 @@ namespace mapnik  {
 	
             bool operator() (double lhs, int rhs) const
 	    {
-	       return  lhs == rhs;
+	      return  (lhs == rhs)? true : false ;
 	    }
 	
             bool operator() (UnicodeString const& lhs, 
                              UnicodeString const& rhs) const
 	    {
-	       return  lhs == rhs;
+	       return  (lhs == rhs) ? true: false;
 	    }
 
             bool operator() (value_null, value_null) const
@@ -139,7 +139,7 @@ namespace mapnik  {
             bool operator() (UnicodeString const& lhs, 
                              UnicodeString const& rhs) const
 	    {
-	       return  lhs != rhs;
+	       return  (lhs != rhs)? true : false;
 	    }
 
             bool operator() (value_null, value_null) const
@@ -187,7 +187,7 @@ namespace mapnik  {
 	
             bool operator() (UnicodeString const& lhs, UnicodeString const& rhs) const
 	    {
-	       return  lhs > rhs;
+	      return  (lhs > rhs) ? true : false ;
 	    }
 
             bool operator() (value_null, value_null) const
@@ -223,7 +223,7 @@ namespace mapnik  {
 	
             bool operator() (UnicodeString const& lhs, UnicodeString const& rhs) const
 	    {
-	       return lhs >= rhs;
+	       return ( lhs >= rhs ) ? true : false ;
 	    }
 
             bool operator() (value_null, value_null) const
@@ -260,7 +260,7 @@ namespace mapnik  {
             bool operator()(UnicodeString const& lhs, 
                             UnicodeString const& rhs ) const
 	    {
-	       return lhs < rhs;
+	      return (lhs < rhs) ? true : false ;
 	    }
 
             bool operator() (value_null, value_null) const
@@ -297,7 +297,7 @@ namespace mapnik  {
             bool operator()(UnicodeString const& lhs, 
                             UnicodeString const& rhs ) const
 	    {
-	      return lhs <= rhs;
+	      return (lhs <= rhs) ? true : false ;
 	    }
 
             bool operator() (value_null, value_null) const
diff --git a/src/envelope.cpp b/src/envelope.cpp
index 75ffd6d2f..7b43a1609 100644
--- a/src/envelope.cpp
+++ b/src/envelope.cpp
@@ -308,12 +308,12 @@ namespace mapnik
     Envelope<T>& Envelope<T>::operator*=(T t)
     {
        coord<T,2> c = center();
-       T sx = 0.5 * width() * t;
-       T sy = 0.5 * height() * t;
-       minx_ = static_cast<T>(c.x - sx);
-       maxx_ = static_cast<T>(c.x + sx);
-       miny_ = static_cast<T>(c.y - sy);
-       maxy_ = static_cast<T>(c.y + sy);
+       T sx = static_cast<T>(0.5 * width()  * t);
+       T sy = static_cast<T>(0.5 * height() * t);
+       minx_ = c.x - sx;
+       maxx_ = c.x + sx;
+       miny_ = c.y - sy;
+       maxy_ = c.y + sy;
        return *this;
     }
    
@@ -321,12 +321,12 @@ namespace mapnik
     Envelope<T>& Envelope<T>::operator/=(T t)
     {
        coord<T,2> c = center();
-       T sx = 0.5 * width() / t;
-       T sy = 0.5 * height() / t;
-       minx_ = static_cast<T>(c.x - sx);
-       maxx_ = static_cast<T>(c.x + sx);
-       miny_ = static_cast<T>(c.y - sy);
-       maxy_ = static_cast<T>(c.y + sy);
+       T sx = static_cast<T>(0.5 * width() / t);
+       T sy = static_cast<T>(0.5 * height() / t);
+       minx_ = c.x - sx;
+       maxx_ = c.x + sx;
+       miny_ = c.y - sy;
+       maxy_ = c.y + sy;
        return *this;
     }
     
diff --git a/src/filter_factory.cpp b/src/filter_factory.cpp
index 04cdd811e..8c178c212 100644
--- a/src/filter_factory.cpp
+++ b/src/filter_factory.cpp
@@ -27,9 +27,8 @@ namespace mapnik
 {
    filter_ptr create_filter (std::string const& wkt,std::string const& encoding)
    {
-      filter_factory<Feature> factory;
       transcoder tr(encoding);
-      return factory.compile(wkt,tr);
+      return filter_factory<Feature>::compile(wkt,tr);
    }
    
    filter_ptr create_filter (std::string const& wkt)
diff --git a/src/proj_transform.cpp b/src/proj_transform.cpp
index ec9cfaf98..f08f9f9c6 100644
--- a/src/proj_transform.cpp
+++ b/src/proj_transform.cpp
@@ -38,8 +38,8 @@ namespace mapnik {
 #ifdef MAPNIK_THREADSAFE
         mutex::scoped_lock lock(projection::mutex_);
 #endif
-        is_source_latlong_ = pj_is_latlong(source_.proj_);
-        is_dest_latlong_ = pj_is_latlong(dest_.proj_);
+        is_source_latlong_ = pj_is_latlong(source_.proj_) ? true : false;
+        is_dest_latlong_ = pj_is_latlong(dest_.proj_) ? true : false ;
         is_source_equal_dest = (source_ == dest_);
     }
     
diff --git a/src/projection.cpp b/src/projection.cpp
index 9143b59f0..a9ecc1ab2 100644
--- a/src/projection.cpp
+++ b/src/projection.cpp
@@ -73,7 +73,7 @@ namespace mapnik {
 #ifdef MAPNIK_THREADSAFE
         mutex::scoped_lock lock(mutex_);
 #endif
-        return pj_is_latlong(proj_);  
+        return pj_is_latlong(proj_) ? true : false;  
     }
     
     std::string const& projection::params() const