--- a/src/ov-cell.h
+++ b/src/ov-cell.h
@@ -88,6 +88,13 @@
 
   size_t byte_size (void) const;
 
+  octave_value sort (octave_idx_type dim = 0, sortmode mode = ASCENDING) const;
+
+  octave_value sort (Array<octave_idx_type> &sidx, octave_idx_type dim = 0,
+		     sortmode mode = ASCENDING) const;
+
+  Array<octave_idx_type> sortrows_idx (sortmode mode = ASCENDING) const;
+
   bool is_matrix_type (void) const { return false; }
 
   bool is_numeric_type (void) const { return false; }
@@ -111,6 +118,8 @@
 
   string_vector all_strings (bool pad = false) const;
 
+  Array<std::string> cellstr_value (void) const;
+
   bool print_as_scalar (void) const;
 
   void print (std::ostream& os, bool pr_as_read_syntax = false) const;