diff --git a/shapes/Shape.cc b/shapes/Shape.cc
index e46e478..4ed75c8 100755
--- a/shapes/Shape.cc
+++ b/shapes/Shape.cc
@@ -2,6 +2,7 @@
 #include "Shape.h"
 #include <algorithm>                /* sort() */
 #include <functional>               /* binary_function */
+#include <utility>
 using namespace std;
 
 Shape::Shape()
@@ -14,6 +15,25 @@ Shape::~Shape()
 {
 }
 
+class IntersectionComparator : public std::binary_function<Shape::Intersection,
+                                                           Shape::Intersection,
+                                                           bool>
+{
+    public:
+        IntersectionComparator(const Vector & refPoint)
+        {
+            m_refPoint = refPoint;
+        }
+        bool operator()(const Shape::Intersection & i1,
+                        const Shape::Intersection & i2) const
+        {
+            return (m_refPoint.dist_to(i1.second)
+                        < m_refPoint.dist_to(i2.second));
+        }
+    protected:
+        Vector m_refPoint;
+};
+
 Shape::IntersectionList
 Shape::IntersectionList::merge(const IntersectionList & other,
                                const Vector & startPoint)
@@ -33,25 +53,7 @@ Shape::IntersectionList::merge(const IntersectionList & other,
         result.add(other.m_intersections[i]);
     }
 
-    class Comparator : public binary_function<Intersection,
-                                              Intersection,
-                                              bool>
-    {
-        public:
-            Comparator(const Vector & refPoint)
-            {
-                m_refPoint = refPoint;
-            }
-            bool operator()(Intersection const & i1, Intersection const & i2) const
-            {
-                return (m_refPoint.dist_to(i1.second)
-                            < m_refPoint.dist_to(i2.second));
-            }
-        protected:
-            Vector m_refPoint;
-    };
-
-    sort(result.m_intersections.begin(), result.m_intersections.end(), Comparator(startPoint));
+    sort(result.begin(), result.end(), IntersectionComparator(startPoint));
 
     return result;
 }