--- a/liboctave/oct-sort.h
+++ b/liboctave/oct-sort.h
@@ -114,7 +114,7 @@
 
   octave_sort (compare_fcn_type);
   
-  ~octave_sort (void) { merge_freemem (); }
+  ~octave_sort (void); 
 
   void set_compare (compare_fcn_type comp) { compare = comp; }
 
@@ -138,6 +138,16 @@
   bool is_sorted_rows (const T *data, 
                        octave_idx_type rows, octave_idx_type cols);
 
+  // Do a binary lookup in a sorted array.
+  octave_idx_type lookup (const T *data, octave_idx_type nel,
+                          const T& value);
+
+  // Ditto, but for an array of values, specializing on long runs.
+  // Adds offset to all indices.
+  void lookup (const T *data, octave_idx_type nel,
+               const T* values, octave_idx_type nvalues,
+               octave_idx_type *idx, octave_idx_type offset = 0);
+
   static bool ascending_compare (typename ref_param<T>::type,
 				 typename ref_param<T>::type);
 
@@ -187,7 +197,7 @@
 
   compare_fcn_type compare;
   
-  MergeState ms;
+  MergeState *ms;
   
     
   template <class Comp>
@@ -277,6 +287,15 @@
   bool is_sorted_rows (const T *data, octave_idx_type rows, 
                        octave_idx_type cols, Comp comp);
 
+  template <class Comp>
+  octave_idx_type lookup (const T *data, octave_idx_type nel,
+                          const T& value, Comp comp);
+
+  template <class Comp>
+  void lookup (const T *data, octave_idx_type nel,
+               const T* values, octave_idx_type nvalues,
+               octave_idx_type *idx, octave_idx_type offset, Comp comp);
+
 };
 
 template <class T>