Made remove_duplicates() take any type rather than just being limited to

rectangle.

dlib/image_transforms/segment_image.h

@@ -595,22 +595,22 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
-    template <typename alloc>
+    template <typename T, typename alloc>
     void remove_duplicates (
-        std::vector<rectangle,alloc>& rects
+        std::vector<T,alloc>& items
     )
     {
-        std::sort(rects.begin(), rects.end(), std::less<rectangle>());
+        std::sort(items.begin(), items.end(), std::less<T>());
         unsigned long num_unique = 1;
-        for (unsigned long i = 1; i < rects.size(); ++i)
+        for (unsigned long i = 1; i < items.size(); ++i)
         {
-            if (rects[i] != rects[i-1])
+            if (items[i] != items[i-1])
             {
-                rects[num_unique++] = rects[i];
+                items[num_unique++] = items[i];
             }
         }
-        if (rects.size() != 0)
-            rects.resize(num_unique);
+        if (items.size() != 0)
+            items.resize(num_unique);
     }
 
 // ----------------------------------------------------------------------------------------

dlib/image_transforms/segment_image_abstract.h

@@ -105,16 +105,20 @@ namespace dlib
 // ----------------------------------------------------------------------------------------
 
     template <
+        template T,
         typename alloc
         >
     void remove_duplicates (
-        std::vector<rectangle,alloc>& rects
+        std::vector<T,alloc>& items 
     );
     /*!
+        requires
+            - T is comparable via operator != and std::less.
         ensures
-            - This function finds any duplicate rectangles in rects and removes the extra
-              instances.  This way, the result is that rects contains only unique rectangle
-              instances.
+            - This function finds any duplicate objects in items and removes the extra
+              instances.  This way, the result is that items contains only unique
+              instances.  It does this by sorting items and removing neighboring elements
+              unless they compare != according to operator !=.
     !*/
 
 // ----------------------------------------------------------------------------------------