expanded class interface REVERSE_COLLECTION_SORTER[X->COMPARABLE]
   -- 
   --  Some algorithms to sort any COLLECTION[COMPARABLE].
   -- 
   --  Elements are sorted using decreasing order: large elements 
   --  at the begining of the colection, small at the end (increasing
   --  order is implemented by class COLLECTION_SORTER).
   -- 
   --  How to use this expanded class :
   -- 
   --           local
   --              sorter: REVERSE_COLLECTION_SORTER[INTEGER];
   --              array: ARRAY[INTEGER];
   --           do
   --              array := <<1,3,2>>;
   --              sorter.sort(array);
   --              check
   --                 sorter.is_sorted(array);
   --              end;
   --              ...
   -- 

feature(s) from REVERSE_COLLECTION_SORTER
   is_sorted (c: COLLECTION[X]): BOOLEAN
      --  Is c already sorted ?
      --  Uses infix ">=" for comparison.

      require
         c /= Void
      ensure
         c.is_equal(old c.twin)

   sort (c: COLLECTION[X])
      --  Sort c using the default most efficient sorting algorithm
      --  already implemented.

      require
         c /= Void
      ensure
         c.count = old c.count;
         is_sorted(c)

   quick_sort (c: COLLECTION[X])
      --  Sort c using the quick sort algorithm.

      require
         c /= Void
      ensure
         c.count = old c.count;
         is_sorted(c)

   von_neuman_sort (c: COLLECTION[X])
      --  Sort c using the Von Neuman algorithm.
      --  This algorithm needs to create a second collection.
      --  Uses infix "<=" for comparison.

      require
         c /= Void
      ensure
         c.count = old c.count;
         is_sorted(c)

   bubble_sort (c: COLLECTION[X])
      --  Sort c using the bubble sort algorithm.
      --  Uses infix ">" for comparison.

      require
         c /= Void
      ensure
         c.count = old c.count;
         is_sorted(c)

   heap_sort (c: COLLECTION[X])
      --  Sort c using the heap sort algorithm.

      require
         c /= Void
      ensure
         c.count = old c.count;
         is_sorted(c)


end of expanded REVERSE_COLLECTION_SORTER[X->COMPARABLE]