--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,14 @@
 Summary of changes for version 2.1.x:
 ------------------------------------
 
+  * The ++ and -- operators now work for indexed matrices, and the
+    following operators now work:
+
+      +=, -=, *=, /=, \=, <<=, >>=, .*=, ./=, .\=, &=, |=
+
+    These operators are currently implemented using a relatively
+    inefficient brute-force method but hey, they work.
+
   * The built-in variable argv is now a list of strings instead of a
     string vector.
 

--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,10 @@
 Fri Oct 30 08:39:30 1998  John W. Eaton  <jwe@bevo.che.wisc.edu>
 
+	* oct-lvalue.cc (octave_lvalue::do_unary_op): Make it work for
+	indexed ops too.
+	* ov.cc (octave_value::unary_op_to_assign_op): New function.
+	(octave_value::do_non_const_unary_op): New function for	indexed ops.
+
 	* parse.y (LEFTDIV_EQ, ELEFTDIV_EQ): New tokens.
 	(assign_expr): Add rules for them.
 	(make_assign_op): Handle them here too.

--- a/src/oct-lvalue.cc
+++ b/src/oct-lvalue.cc
@@ -67,11 +67,7 @@
   if (idx.empty ())
     val->do_non_const_unary_op (op);
   else
-    {
-      string on = octave_value::unary_op_as_string (op);
-      error ("indexed operations not implemented yet for operator `%s'",
-	     on.c_str ());
-    }
+    val->do_non_const_unary_op (op, idx);
 
   if (chg_fcn && ! error_state && chg_fcn () < 0)
     *val = saved_val;

--- a/src/ov.cc
+++ b/src/ov.cc
@@ -1229,6 +1229,30 @@
     }
 }
 
+static void
+gripe_unary_op_failed_or_no_method (const string& on, const string& tn)
+{
+  error ("operator %s: no method, or unable to evaluate for %s operand",
+	 on.c_str (), tn.c_str ());
+}
+
+void
+octave_value::do_non_const_unary_op (octave_value::unary_op op,
+				     const octave_value_list& idx)
+{
+  // XXX FIXME XXX -- only do the following stuff if we can't find a
+  // specific function to call to handle the op= operation for the
+  // types we have.
+
+  assign_op assop = unary_op_to_assign_op (op);
+
+  if (! error_state)
+    assign (assop, idx, 1.0);
+  else
+    gripe_unary_op_failed_or_no_method (unary_op_as_string (op),
+					type_name ());
+}
+
 // Current indentation.
 int octave_value::curr_print_indent_level = 0;
 
@@ -1275,6 +1299,31 @@
   curr_print_indent_level = 0;
 }
 
+octave_value::assign_op
+octave_value::unary_op_to_assign_op (unary_op op)
+{
+  assign_op binop = unknown_assign_op;
+
+  switch (op)
+    {
+    case incr:
+      binop = add_eq;
+      break;
+
+    case decr:
+      binop = sub_eq;
+      break;
+
+    default:
+      {
+	string on = unary_op_as_string (op);
+	error ("operator %s: no assign operator found", on.c_str ());
+      }
+    }
+
+  return binop;
+}
+
 octave_value::binary_op 
 octave_value::op_eq_to_binary_op (assign_op op)
 {

--- a/src/ov.h
+++ b/src/ov.h
@@ -471,6 +471,9 @@
 
   void do_non_const_unary_op (octave_value::unary_op);
 
+  void do_non_const_unary_op (octave_value::unary_op,
+			      const octave_value_list& idx);
+
   friend octave_value do_binary_op (octave_value::binary_op,
 				    const octave_value&,
 				    const octave_value&);
@@ -520,6 +523,8 @@
   static int curr_print_indent_level;
   static bool beginning_of_line;
 
+  assign_op unary_op_to_assign_op (unary_op op);
+
   binary_op op_eq_to_binary_op (assign_op op);
 
   void simple_assign (assign_op orig_op, const octave_value_list& idx,