# HG changeset patch
# User jwe
# Date 949487185 0
# Node ID b80bbb43a1a951eb9eb8591a38a36826316227f2
# Parent  bd422cf62f0c92a6004b0cbc13448100c508ed1e
[project @ 2000-02-02 10:25:52 by jwe]

diff --git a/src/ChangeLog b/src/ChangeLog
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2000-02-02  John W. Eaton  <jwe@bevo.che.wisc.edu>
+
+	* All source files: Sprinkle with std:: qualifier as needed.
+
 2000-01-31  John W. Eaton  <jwe@bevo.che.wisc.edu>
 
 	* sighandlers.cc (install_signal_handlers): Add std:: qualifier
diff --git a/src/DLD-FUNCTIONS/balance.cc b/src/DLD-FUNCTIONS/balance.cc
--- a/src/DLD-FUNCTIONS/balance.cc
+++ b/src/DLD-FUNCTIONS/balance.cc
@@ -116,7 +116,7 @@
 
   // determine if it's AEP or GEP
   int AEPcase = nargin == 1 ? 1 : args(1).is_string ();
-  string bal_job;
+  std::string bal_job;
 
   // problem dimension
   int nn = args(0).rows ();
diff --git a/src/DLD-FUNCTIONS/colloc.cc b/src/DLD-FUNCTIONS/colloc.cc
--- a/src/DLD-FUNCTIONS/colloc.cc
+++ b/src/DLD-FUNCTIONS/colloc.cc
@@ -91,7 +91,7 @@
 	      return retval;
 	    }
 
-	  string s = args(i).string_value ();
+	  std::string s = args(i).string_value ();
 
 	  if ((s.length () == 1 && (s[0] == 'R' || s[0] == 'r'))
 	      || s == "right")
diff --git a/src/DLD-FUNCTIONS/dassl.cc b/src/DLD-FUNCTIONS/dassl.cc
--- a/src/DLD-FUNCTIONS/dassl.cc
+++ b/src/DLD-FUNCTIONS/dassl.cc
@@ -26,7 +26,7 @@
 
 #include <string>
 
-#include <iostream.h>
+#include <iostream>
 
 #include "DASSL.h"
 
@@ -300,7 +300,7 @@
 };
 
 static void
-print_dassl_option_list (ostream& os)
+print_dassl_option_list (std::ostream& os)
 {
   print_usage ("dassl_options", 1);
 
@@ -330,7 +330,7 @@
 }
 
 static void
-set_dassl_option (const string& keyword, double val)
+set_dassl_option (const std::string& keyword, double val)
 {
   DASSL_OPTIONS *list = dassl_option_table;
 
@@ -350,7 +350,7 @@
 }
 
 static octave_value_list
-show_dassl_option (const string& keyword)
+show_dassl_option (const std::string& keyword)
 {
   octave_value retval;
 
@@ -398,7 +398,7 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      string keyword = args(0).string_value ();
+      std::string keyword = args(0).string_value ();
 
       if (! error_state)
 	{
diff --git a/src/DLD-FUNCTIONS/fsolve.cc b/src/DLD-FUNCTIONS/fsolve.cc
--- a/src/DLD-FUNCTIONS/fsolve.cc
+++ b/src/DLD-FUNCTIONS/fsolve.cc
@@ -26,7 +26,7 @@
 
 #include <string>
 
-#include <iostream.h>
+#include <iostream>
 
 #include "NLEqn.h"
 
@@ -240,7 +240,7 @@
 };
 
 static void
-print_fsolve_option_list (ostream& os)
+print_fsolve_option_list (std::ostream& os)
 {
   print_usage ("fsolve_options", 1);
 
@@ -270,7 +270,7 @@
 }
 
 static void
-set_fsolve_option (const string& keyword, double val)
+set_fsolve_option (const std::string& keyword, double val)
 {
   NLEQN_OPTIONS *list = fsolve_option_table;
 
@@ -290,7 +290,7 @@
 }
 
 static octave_value_list
-show_fsolve_option (const string& keyword)
+show_fsolve_option (const std::string& keyword)
 {
   octave_value retval;
 
@@ -338,7 +338,7 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      string keyword = args(0).string_value ();
+      std::string keyword = args(0).string_value ();
 
       if (! error_state)
 	{
diff --git a/src/DLD-FUNCTIONS/getgrent.cc b/src/DLD-FUNCTIONS/getgrent.cc
--- a/src/DLD-FUNCTIONS/getgrent.cc
+++ b/src/DLD-FUNCTIONS/getgrent.cc
@@ -73,14 +73,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = 0.0;
 
   int nargin = args.length ();
 
   if (nargin == 0)
     {
-      string msg;
+      std::string msg;
 
       retval(0) = mk_gr_map (octave_group::getgrent (msg));
       retval(1) = msg;
@@ -101,7 +101,7 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = 0.0;
 
   int nargin = args.length ();
@@ -116,7 +116,7 @@
 	    {
 	      gid_t gid = static_cast<gid_t> (dval);
 
-	      string msg;
+	      std::string msg;
 
 	      retval(0) = mk_gr_map (octave_group::getgrgid (gid, msg));
 	      retval(1) = msg;
@@ -141,18 +141,18 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = 0.0;
 
   int nargin = args.length ();
 
   if (nargin == 1)
     {
-      string s = args(0).string_value ();
+      std::string s = args(0).string_value ();
 
       if (! error_state)
 	{
-	  string msg;
+	  std::string msg;
 
 	  retval(0) = mk_gr_map (octave_group::getgrnam (s.c_str (), msg));
 	  retval(1) = msg;
@@ -172,14 +172,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
 
   if (nargin == 0)
     {
-      string msg;
+      std::string msg;
 
       retval(0) = static_cast<double> (octave_group::setgrent (msg));
       retval(1) = msg;
@@ -198,14 +198,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
 
   if (nargin == 0)
     {
-      string msg;
+      std::string msg;
 
       retval(0) = static_cast<double> (octave_group::endgrent (msg));
       retval(1) = msg;
diff --git a/src/DLD-FUNCTIONS/getpwent.cc b/src/DLD-FUNCTIONS/getpwent.cc
--- a/src/DLD-FUNCTIONS/getpwent.cc
+++ b/src/DLD-FUNCTIONS/getpwent.cc
@@ -77,14 +77,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = 0.0;
 
   int nargin = args.length ();
 
   if (nargin == 0)
     {
-      string msg;
+      std::string msg;
 
       retval(0) = mk_pw_map (octave_passwd::getpwent (msg));
       retval(1) = msg;
@@ -105,7 +105,7 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = 0.0;
 
   int nargin = args.length ();
@@ -120,7 +120,7 @@
 	    {
 	      uid_t uid = static_cast<uid_t> (dval);
 
-	      string msg;
+	      std::string msg;
 
 	      retval(0) = mk_pw_map (octave_passwd::getpwuid (uid, msg));
 	      retval(1) = msg;
@@ -145,18 +145,18 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = 0.0;
 
   int nargin = args.length ();
 
   if (nargin == 1)
     {
-      string s = args(0).string_value ();
+      std::string s = args(0).string_value ();
 
       if (! error_state)
 	{
-	  string msg;
+	  std::string msg;
 
 	  retval(0) = mk_pw_map (octave_passwd::getpwnam (s.c_str (), msg));
 	  retval(1) = msg;
@@ -176,14 +176,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
 
   if (nargin == 0)
     {
-      string msg;
+      std::string msg;
 
       retval(0) = static_cast<double> (octave_passwd::setpwent (msg));
       retval(1) = msg;
@@ -202,14 +202,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
 
   if (nargin == 0)
     {
-      string msg;
+      std::string msg;
 
       retval(0) = static_cast<double> (octave_passwd::endpwent (msg));
       retval(1) = msg;
diff --git a/src/DLD-FUNCTIONS/lsode.cc b/src/DLD-FUNCTIONS/lsode.cc
--- a/src/DLD-FUNCTIONS/lsode.cc
+++ b/src/DLD-FUNCTIONS/lsode.cc
@@ -26,7 +26,7 @@
 
 #include <string>
 
-#include <iostream.h>
+#include <iostream>
 
 #include "LSODE.h"
 #include "lo-mappers.h"
@@ -360,7 +360,7 @@
 };
 
 static void
-print_lsode_option_list (ostream& os)
+print_lsode_option_list (std::ostream& os)
 {
   print_usage ("lsode_options", 1);
 
@@ -399,7 +399,7 @@
 }
 
 static void
-set_lsode_option (const string& keyword, double val)
+set_lsode_option (const std::string& keyword, double val)
 {
   LSODE_OPTIONS *list = lsode_option_table;
 
@@ -429,7 +429,7 @@
 }
 
 static octave_value_list
-show_lsode_option (const string& keyword)
+show_lsode_option (const std::string& keyword)
 {
   octave_value retval;
 
@@ -488,7 +488,7 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      string keyword = args(0).string_value ();
+      std::string keyword = args(0).string_value ();
 
       if (! error_state)
 	{
diff --git a/src/DLD-FUNCTIONS/quad.cc b/src/DLD-FUNCTIONS/quad.cc
--- a/src/DLD-FUNCTIONS/quad.cc
+++ b/src/DLD-FUNCTIONS/quad.cc
@@ -26,7 +26,7 @@
 
 #include <string>
 
-#include <iostream.h>
+#include <iostream>
 
 #include "Quad.h"
 #include "lo-mappers.h"
@@ -320,7 +320,7 @@
 };
 
 static void
-print_quad_option_list (ostream& os)
+print_quad_option_list (std::ostream& os)
 {
   print_usage ("quad_options", 1);
 
@@ -350,7 +350,7 @@
 }
 
 static void
-set_quad_option (const string& keyword, double val)
+set_quad_option (const std::string& keyword, double val)
 {
   QUAD_OPTIONS *list = quad_option_table;
 
@@ -370,7 +370,7 @@
 }
 
 static octave_value_list
-show_quad_option (const string& keyword)
+show_quad_option (const std::string& keyword)
 {
   octave_value retval;
 
@@ -412,7 +412,7 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      string keyword = args(0).string_value ();
+      std::string keyword = args(0).string_value ();
 
       if (! error_state)
 	{
diff --git a/src/DLD-FUNCTIONS/qz.cc b/src/DLD-FUNCTIONS/qz.cc
--- a/src/DLD-FUNCTIONS/qz.cc
+++ b/src/DLD-FUNCTIONS/qz.cc
@@ -30,7 +30,7 @@
 #include "config.h"
 
 #include <cfloat>
-#include <iostream.h>
+#include <iostream>
 #include <iomanip.h>
 #include <math.h>
 #include <string.h>
@@ -259,7 +259,7 @@
 #endif
 
   // Determine ordering option
-  string ord_job;
+  std::string ord_job;
   static double safmin;
 
   if (nargin == 2)
diff --git a/src/DLD-FUNCTIONS/rand.cc b/src/DLD-FUNCTIONS/rand.cc
--- a/src/DLD-FUNCTIONS/rand.cc
+++ b/src/DLD-FUNCTIONS/rand.cc
@@ -165,7 +165,7 @@
 
       if (tmp.is_string ())
 	{
-	  string s_arg = tmp.string_value ();
+	  std::string s_arg = tmp.string_value ();
 
 	  if (s_arg == "dist")
 	    {
diff --git a/src/DLD-FUNCTIONS/schur.cc b/src/DLD-FUNCTIONS/schur.cc
--- a/src/DLD-FUNCTIONS/schur.cc
+++ b/src/DLD-FUNCTIONS/schur.cc
@@ -255,7 +255,7 @@
 
   octave_value arg = args(0);
 
-  string ord;
+  std::string ord;
 
   if (nargin == 2)
     {
diff --git a/src/DLD-FUNCTIONS/time.cc b/src/DLD-FUNCTIONS/time.cc
--- a/src/DLD-FUNCTIONS/time.cc
+++ b/src/DLD-FUNCTIONS/time.cc
@@ -369,7 +369,7 @@
 
   if (args.length () == 2)
     {
-      string fmt = args(0).string_value ();
+      std::string fmt = args(0).string_value ();
 
       if (! error_state)
 	{
@@ -407,11 +407,11 @@
 
   if (args.length () == 2)
     {
-      string str = args(0).string_value ();
+      std::string str = args(0).string_value ();
 
       if (! error_state)
 	{
-	  string fmt = args(1).string_value ();
+	  std::string fmt = args(1).string_value ();
 
 	  if (! error_state)
 	    {
diff --git a/src/Map.cc b/src/Map.cc
--- a/src/Map.cc
+++ b/src/Map.cc
@@ -46,7 +46,7 @@
 #include "Map.h"
 
 static unsigned int
-hash (const string& str)
+hash (const std::string& str)
 {
   unsigned h = 0;
   for (unsigned i = 0; i < str.length (); i++)
@@ -56,7 +56,7 @@
 
 template <class C>
 Pix
-Map<C>::seek (const string& item) const
+Map<C>::seek (const std::string& item) const
 {
   Pix i = 0;
 
@@ -94,14 +94,14 @@
 
 template <class C>
 int
-Map<C>::contains (const string& item) const
+Map<C>::contains (const std::string& item) const
 {
   return seek (item) != 0;
 }
 
 template <class C>
 void
-Map<C>::error (const string& msg) const
+Map<C>::error (const std::string& msg) const
 {
   cerr << "Map: " << msg << "\n";
 }
@@ -154,7 +154,7 @@
 
 template <class C>
 Pix
-CHMap<C>::seek (const string& key) const
+CHMap<C>::seek (const std::string& key) const
 {
   unsigned int h = hash (key) % size;
 
@@ -167,7 +167,7 @@
 
 template <class C>
 C&
-CHMap<C>::operator [] (const string& item)
+CHMap<C>::operator [] (const std::string& item)
 {
   unsigned int h = hash (item) % size;
 
@@ -184,7 +184,7 @@
 
 template <class C>
 void
-CHMap<C>::del (const string& key)
+CHMap<C>::del (const std::string& key)
 {
   unsigned int h = hash (key) % size;
 
diff --git a/src/Map.h b/src/Map.h
--- a/src/Map.h
+++ b/src/Map.h
@@ -59,25 +59,25 @@
   int length (void) const { return count; }	// current number of items
   int empty (void) const { return count == 0; }
 
-  virtual int contains (const string& key) const;  // is key mapped?
+  virtual int contains (const std::string& key) const;  // is key mapped?
 
   virtual void clear (void);			// delete all items
 	      
-  virtual C& operator [] (const string& key) = 0;  // access contents by key
+  virtual C& operator [] (const std::string& key) = 0;  // access contents by key
 	      
-  virtual void del (const string& key) = 0;	// delete entry
+  virtual void del (const std::string& key) = 0;	// delete entry
 	      
   virtual Pix first (void) const = 0;		// Pix of first item or 0
   virtual void next (Pix& i) const = 0;		// advance to next or 0
-  virtual string key (Pix i) const = 0;		// access key at i
+  virtual std::string key (Pix i) const = 0;		// access key at i
   virtual C& contents (Pix i) const = 0;	// access contents at i
 
   virtual int owns (Pix i) const;		// is i a valid Pix  ?
-  virtual Pix seek (const string& key) const;	// Pix of key
+  virtual Pix seek (const std::string& key) const;	// Pix of key
 
   C& dflt (void) { return def; }		// access default val
 
-  void error (const string& msg) const;
+  void error (const std::string& msg) const;
 
   virtual int OK (void) const = 0;		// rep invariant
 };
@@ -86,12 +86,12 @@
 struct CHNode
 {
   CHNode *tl;
-  string hd;
+  std::string hd;
   C cont;
 
   CHNode (void) : tl (0), hd (), cont () { }
 
-  CHNode (const string& h, const C& c, CHNode *t = 0)
+  CHNode (const std::string& h, const C& c, CHNode *t = 0)
     : tl (t), hd (h), cont (c) { }
 
   ~CHNode (void) { }
@@ -119,14 +119,14 @@
       delete tab;
     }
 
-  C& operator [] (const string& key);
+  C& operator [] (const std::string& key);
 
-  void del (const string& key);
+  void del (const std::string& key);
 
   Pix first (void) const;
   void next (Pix& i) const;
 
-  string key (Pix p) const
+  std::string key (Pix p) const
     {
       if (p == 0)
 	error ("null Pix");
@@ -142,9 +142,9 @@
      return ((CHNode<C> *) p)->cont;
    }
 
-  Pix seek (const string& key) const;
+  Pix seek (const std::string& key) const;
 
-  int contains (const string& key) const
+  int contains (const std::string& key) const
     {
       return seek (key) != 0;
     }
diff --git a/src/OPERATORS/op-fil-b.cc b/src/OPERATORS/op-fil-b.cc
--- a/src/OPERATORS/op-fil-b.cc
+++ b/src/OPERATORS/op-fil-b.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/OPERATORS/op-fil-bm.cc b/src/OPERATORS/op-fil-bm.cc
--- a/src/OPERATORS/op-fil-bm.cc
+++ b/src/OPERATORS/op-fil-bm.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/OPERATORS/op-fil-cm.cc b/src/OPERATORS/op-fil-cm.cc
--- a/src/OPERATORS/op-fil-cm.cc
+++ b/src/OPERATORS/op-fil-cm.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/OPERATORS/op-fil-cs.cc b/src/OPERATORS/op-fil-cs.cc
--- a/src/OPERATORS/op-fil-cs.cc
+++ b/src/OPERATORS/op-fil-cs.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/OPERATORS/op-fil-lis.cc b/src/OPERATORS/op-fil-lis.cc
--- a/src/OPERATORS/op-fil-lis.cc
+++ b/src/OPERATORS/op-fil-lis.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/OPERATORS/op-fil-m.cc b/src/OPERATORS/op-fil-m.cc
--- a/src/OPERATORS/op-fil-m.cc
+++ b/src/OPERATORS/op-fil-m.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/OPERATORS/op-fil-rec.cc b/src/OPERATORS/op-fil-rec.cc
--- a/src/OPERATORS/op-fil-rec.cc
+++ b/src/OPERATORS/op-fil-rec.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/OPERATORS/op-fil-s.cc b/src/OPERATORS/op-fil-s.cc
--- a/src/OPERATORS/op-fil-s.cc
+++ b/src/OPERATORS/op-fil-s.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/OPERATORS/op-fil-str.cc b/src/OPERATORS/op-fil-str.cc
--- a/src/OPERATORS/op-fil-str.cc
+++ b/src/OPERATORS/op-fil-str.cc
@@ -28,7 +28,7 @@
 #include <config.h>
 #endif
 
-#include <iostream.h>
+#include <iostream>
 
 #include "mach-info.h"
 
@@ -50,11 +50,11 @@
 
   if (oct_stream)
     {
-      ostream *osp = oct_stream.output_stream ();
+      std::ostream *osp = oct_stream.output_stream ();
 
       if (osp)
 	{
-	  ostream& os = *osp;
+	  std::ostream& os = *osp;
 
 	  v2.print_raw (os);
 	}
diff --git a/src/TEMPLATE-INST/SLStack-str.cc b/src/TEMPLATE-INST/SLStack-str.cc
--- a/src/TEMPLATE-INST/SLStack-str.cc
+++ b/src/TEMPLATE-INST/SLStack-str.cc
@@ -37,12 +37,12 @@
 
 #include <string>
 
-template class SLNode<string>;
-template class SLList<string>;
+template class SLNode<std:string>;
+template class SLList<std:string>;
 
-template class Stack<string>;
+template class Stack<std:string>;
 
-template class SLStack<string>;
+template class SLStack<std:string>;
 
 /*
 ;;; Local Variables: ***
diff --git a/src/data.cc b/src/data.cc
--- a/src/data.cc
+++ b/src/data.cc
@@ -984,7 +984,7 @@
 
       if (args(0).is_map () && args(1).is_string ())
 	{
-	  string s = args(1).string_value ();
+	  std::string s = args(1).string_value ();
 	  octave_value tmp = args(0).do_struct_elt_index_op (s, true);
 	  retval = static_cast<double> (tmp.is_defined ());
 	}
diff --git a/src/defaults.cc b/src/defaults.cc
--- a/src/defaults.cc
+++ b/src/defaults.cc
@@ -51,44 +51,44 @@
 #include "variables.h"
 #include <version.h>
 
-string Voctave_home;
+std::string Voctave_home;
 
-string Vbin_dir;
-string Vinfo_dir;
-string Vdata_dir;
-string Vlibexec_dir;
-string Varch_lib_dir;
-string Vlocal_arch_lib_dir;
-string Vfcn_file_dir;
+std::string Vbin_dir;
+std::string Vinfo_dir;
+std::string Vdata_dir;
+std::string Vlibexec_dir;
+std::string Varch_lib_dir;
+std::string Vlocal_arch_lib_dir;
+std::string Vfcn_file_dir;
 
 // The path that will be searched for programs that we execute.
 // (--exec-path path)
-string Vexec_path;
+std::string Vexec_path;
 
 // Load path specified on command line.
 // (--path path; -p path)
-static string Vload_path;
+static std::string Vload_path;
 
 // The default load path with OCTAVE_HOME appropriately substituted.
-static string Vdefault_load_path;
+static std::string Vdefault_load_path;
 
 // And the cached directory path corresponding to Vload_path.
 dir_path Vload_path_dir_path;
 
 // Name of the editor to be invoked by the edit_history command.
-string Veditor;
+std::string Veditor;
 
-string Vimagepath;
+std::string Vimagepath;
 
-string Vlocal_site_defaults_file;
-string Vsite_defaults_file;
+std::string Vlocal_site_defaults_file;
+std::string Vsite_defaults_file;
 
 static string
-subst_octave_home (const string& s)
+subst_octave_home (const std::string& s)
 {
-  string retval;
+  std::string retval;
 
-  string prefix = OCTAVE_PREFIX;
+  std::string prefix = OCTAVE_PREFIX;
 
   retval = s;
 
@@ -109,9 +109,9 @@
 static void
 set_octave_home (void)
 {
-  string oh = octave_env::getenv ("OCTAVE_HOME");
+  std::string oh = octave_env::getenv ("OCTAVE_HOME");
 
-  Voctave_home = oh.empty () ? string (OCTAVE_PREFIX) : oh;
+  Voctave_home = oh.empty () ? std::string (OCTAVE_PREFIX) : oh;
 }
 
 static void
@@ -159,20 +159,20 @@
 static void
 set_default_exec_path (void)
 {
-  string octave_exec_path = octave_env::getenv ("OCTAVE_EXEC_PATH");
+  std::string octave_exec_path = octave_env::getenv ("OCTAVE_EXEC_PATH");
 
   if (octave_exec_path.empty ())
     {
-      string shell_path = octave_env::getenv ("PATH");
+      std::string shell_path = octave_env::getenv ("PATH");
 
       if (! shell_path.empty ())
 	{
-	  Vexec_path = string (":");
+	  Vexec_path = std::string (":");
 	  Vexec_path.append (shell_path);
 	}
     }
   else
-    Vexec_path = string (octave_exec_path);
+    Vexec_path = std::string (octave_exec_path);
 }
 
 static void
@@ -180,9 +180,9 @@
 {
   Vdefault_load_path = subst_octave_home (OCTAVE_FCNFILEPATH);
 
-  string oct_path = octave_env::getenv ("OCTAVE_PATH");
+  std::string oct_path = octave_env::getenv ("OCTAVE_PATH");
 
-  Vload_path = oct_path.empty () ? string (":") : oct_path;
+  Vload_path = oct_path.empty () ? std::string (":") : oct_path;
 
   Vload_path_dir_path = dir_path (Vload_path, Vdefault_load_path);
 }
@@ -190,9 +190,9 @@
 static void
 set_default_info_file (void)
 {
-  string std_info_file = subst_octave_home (OCTAVE_INFOFILE);
+  std::string std_info_file = subst_octave_home (OCTAVE_INFOFILE);
 
-  string oct_info_file = octave_env::getenv ("OCTAVE_INFO_FILE");
+  std::string oct_info_file = octave_env::getenv ("OCTAVE_INFO_FILE");
 
   Vinfo_file = oct_info_file.empty () ? std_info_file : oct_info_file;
 }
@@ -200,12 +200,12 @@
 static void
 set_default_info_prog (void)
 {
-  string oct_info_prog = octave_env::getenv ("OCTAVE_INFO_PROGRAM");
+  std::string oct_info_prog = octave_env::getenv ("OCTAVE_INFO_PROGRAM");
 
   if (oct_info_prog.empty ())
     Vinfo_prog = "info";
   else
-    Vinfo_prog = string (oct_info_prog);
+    Vinfo_prog = std::string (oct_info_prog);
 }
 
 static void
@@ -213,7 +213,7 @@
 {
   Veditor = "emacs";
 
-  string env_editor = octave_env::getenv ("EDITOR");
+  std::string env_editor = octave_env::getenv ("EDITOR");
 
   if (! env_editor.empty ())
     Veditor = env_editor;
@@ -234,9 +234,9 @@
 }
 
 string
-maybe_add_default_load_path (const string& pathstring)
+maybe_add_default_load_path (const std::string& pathstring)
 {
-  string retval;
+  std::string retval;
 
   if (! pathstring.empty ())
     {
@@ -306,7 +306,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("EDITOR");
+  std::string s = builtin_string_variable ("EDITOR");
 
   if (s.empty ())
     {
@@ -324,7 +324,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("EXEC_PATH");
+  std::string s = builtin_string_variable ("EXEC_PATH");
 
   if (s.empty ())
     {
@@ -335,10 +335,10 @@
     {
       Vexec_path = s;
 
-      string std_path = Vlocal_arch_lib_dir + string (SEPCHAR_STR)
-	+ Varch_lib_dir + string (SEPCHAR_STR) + Vbin_dir;
+      std::string std_path = Vlocal_arch_lib_dir + std::string (SEPCHAR_STR)
+	+ Varch_lib_dir + std::string (SEPCHAR_STR) + Vbin_dir;
 
-      string path;
+      std::string path;
 
       int eplen = Vexec_path.length ();
 
@@ -376,7 +376,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("IMAGEPATH");
+  std::string s = builtin_string_variable ("IMAGEPATH");
 
   if (s.empty ())
     {
@@ -394,7 +394,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("LOADPATH");
+  std::string s = builtin_string_variable ("LOADPATH");
 
   if (s.empty ())
     {
diff --git a/src/defun-int.h b/src/defun-int.h
--- a/src/defun-int.h
+++ b/src/defun-int.h
@@ -33,34 +33,34 @@
 
 class octave_value;
 
-extern void print_usage (const string& nm, bool just_usage = false);
+extern void print_usage (const std::string& nm, bool just_usage = false);
 
-extern void check_version (const string& version, const string& fcn);
+extern void check_version (const std::string& version, const std::string& fcn);
 
 extern void
 install_builtin_mapper (octave_mapper *mf);
 
 extern void
-install_builtin_function (octave_builtin::fcn f, const string& name,
-			  const string& doc, bool is_text_fcn = false);
+install_builtin_function (octave_builtin::fcn f, const std::string& name,
+			  const std::string& doc, bool is_text_fcn = false);
 
 extern void
-install_builtin_variable (const string& n, const octave_value& v,
+install_builtin_variable (const std::string& n, const octave_value& v,
 			  bool p, bool e,
 			  symbol_record::change_function chg_fcn,
-			  const string& h);
+			  const std::string& h);
 
 extern void
-install_builtin_constant (const string& n, const octave_value& v,
-			  bool p, const string& h);
+install_builtin_constant (const std::string& n, const octave_value& v,
+			  bool p, const std::string& h);
 
 extern void
-install_dld_function (octave_dld_function::fcn f, const string& name,
+install_dld_function (octave_dld_function::fcn f, const std::string& name,
 		      const octave_shlib& shl,
-		      const string& doc, bool is_text_fcn = false);
+		      const std::string& doc, bool is_text_fcn = false);
 
 extern void
-alias_builtin (const string& alias, const string& name);
+alias_builtin (const std::string& alias, const std::string& name);
 
 #define DECLARE_FUN(name, args_name, nargout_name) \
   octave_value_list \
@@ -68,7 +68,7 @@
 
 // Define the code that will be used to insert the new function into
 // the symbol table.  We look for this name instead of the actual
-// function so that we can easily install the doc string too.
+// function so that we can easily install the doc std::string too.
 
 typedef bool (*octave_dld_fcn_installer) (const octave_shlib&);
 
diff --git a/src/defun.cc b/src/defun.cc
--- a/src/defun.cc
+++ b/src/defun.cc
@@ -40,13 +40,13 @@
 #include "variables.h"
 
 void
-print_usage (const string& nm, bool just_usage)
+print_usage (const std::string& nm, bool just_usage)
 {
   symbol_record *sym_rec = global_sym_tab->lookup (nm);
 
   if (sym_rec)
     {
-      string h = sym_rec->help ();
+      std::string h = sym_rec->help ();
 
       if (h.length () > 0)
 	{
@@ -65,7 +65,7 @@
 }
 
 void
-check_version (const string& version, const string& fcn)
+check_version (const std::string& version, const std::string& fcn)
 {
   if (version != OCTAVE_VERSION)
     warning ("incompatible version %s found in function `%s'",
@@ -90,8 +90,8 @@
 }
 
 void
-install_builtin_function (octave_builtin::fcn f, const string& name,
-			  const string& doc, bool is_text_fcn)
+install_builtin_function (octave_builtin::fcn f, const std::string& name,
+			  const std::string& doc, bool is_text_fcn)
 {
   symbol_record *sym_rec = global_sym_tab->lookup (name, true);
 
@@ -108,25 +108,25 @@
 }
 
 void
-install_builtin_constant (const string& name, const octave_value& val,
-			  bool protect, const string& help)
+install_builtin_constant (const std::string& name, const octave_value& val,
+			  bool protect, const std::string& help)
 {
   bind_builtin_constant (name, val, protect, false, help);
 }
 
 void
-install_builtin_variable (const string& name, const octave_value& value,
+install_builtin_variable (const std::string& name, const octave_value& value,
 			  bool protect, bool eternal,
 			  symbol_record::change_function chg_fcn,
-			  const string& doc)
+			  const std::string& doc)
 {
   bind_builtin_variable (name, value, protect, eternal, chg_fcn, doc);
 }
 
 void
-install_dld_function (octave_dld_function::fcn f, const string& name,
+install_dld_function (octave_dld_function::fcn f, const std::string& name,
 		      const octave_shlib& shl,
-		      const string& doc, bool is_text_fcn)
+		      const std::string& doc, bool is_text_fcn)
 {
   symbol_record *sym_rec = global_sym_tab->lookup (name, true);
 
@@ -143,7 +143,7 @@
 }
 
 void
-alias_builtin (const string& alias, const string& name)
+alias_builtin (const std::string& alias, const std::string& name)
 {
   symbol_record *sr_name = global_sym_tab->lookup (name);
 
diff --git a/src/defun.h b/src/defun.h
--- a/src/defun.h
+++ b/src/defun.h
@@ -60,7 +60,7 @@
 
 // This one can be used when `name' cannot be used directly (if it is
 // already defined as a macro).  In that case, name is already a
-// quoted string, and the name of the structure has to be passed too.
+// quoted std::string, and the name of the structure has to be passed too.
 
 #define DEFCONSTX(name, sname, defn, doc) \
   DEFCONSTX_INTERNAL (name, sname, defn, doc)
diff --git a/src/dirfns.cc b/src/dirfns.cc
--- a/src/dirfns.cc
+++ b/src/dirfns.cc
@@ -66,7 +66,7 @@
 // this function can be eliminated.
 
 static int
-octave_change_to_directory (const string& newdir)
+octave_change_to_directory (const std::string& newdir)
 {
   int cd_ok = octave_env::chdir (newdir);
 
@@ -107,7 +107,7 @@
 
   if (argc > 1)
     {
-      string dirname = file_ops::tilde_expand (argv[1]);
+      std::string dirname = file_ops::tilde_expand (argv[1]);
 
       if (dirname.length () > 0
 	  && ! octave_change_to_directory (dirname))
@@ -117,7 +117,7 @@
     }
   else
     {
-      string home_dir = octave_env::get_home_directory ();
+      std::string home_dir = octave_env::get_home_directory ();
 
       if (home_dir.empty () || ! octave_change_to_directory (home_dir))
 	return retval;
@@ -163,7 +163,7 @@
   if (error_state)
     return retval;
 
-  ostrstream ls_buf;
+  std::ostrstream ls_buf;
 
   ls_buf << "ls -C ";
   for (int i = 1; i < argc; i++)
@@ -220,7 +220,7 @@
 {
   octave_value_list retval;
 
-  string directory = octave_env::getcwd ();
+  std::string directory = octave_env::getcwd ();
 
   if (directory.empty ())
     warning ("pwd: can't find working directory!");
@@ -248,13 +248,13 @@
 {
   octave_value_list retval;
 
-  retval(2) = string ();
+  retval(2) = std::string ();
   retval(1) = -1.0;
   retval(0) = Matrix ();
 
   if (args.length () == 1)
     {
-      string dirname = args(0).string_value ();
+      std::string dirname = args(0).string_value ();
 
       if (error_state)
 	gripe_wrong_type_arg ("readdir", args(0));
@@ -295,18 +295,18 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   if (args.length () == 1)
     {
-      string dirname = args(0).string_value ();
+      std::string dirname = args(0).string_value ();
 
       if (error_state)
 	gripe_wrong_type_arg ("mkdir", args(0));
       else
 	{
-	  string msg;
+	  std::string msg;
 
 	  int status = file_ops::mkdir (file_ops::tilde_expand (dirname),
 					0777, msg);
@@ -335,18 +335,18 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   if (args.length () == 1)
     {
-      string dirname = args(0).string_value ();
+      std::string dirname = args(0).string_value ();
 
       if (error_state)
 	gripe_wrong_type_arg ("rmdir", args(0));
       else
 	{
-	  string msg;
+	  std::string msg;
 
 	  int status = file_ops::rmdir (file_ops::tilde_expand (dirname), msg);
 
@@ -374,24 +374,24 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   if (args.length () == 2)
     {
-      string from = args(0).string_value ();
+      std::string from = args(0).string_value ();
 
       if (error_state)
 	gripe_wrong_type_arg ("rename", args(0));
       else
 	{
-	  string to = args(1).string_value ();
+	  std::string to = args(1).string_value ();
 
 	  if (error_state)
 	    gripe_wrong_type_arg ("rename", args(1));
 	  else
 	    {
-	      string msg;
+	      std::string msg;
 
 	      int status = file_ops::rename (from, to, msg);
 
diff --git a/src/dirfns.h b/src/dirfns.h
--- a/src/dirfns.h
+++ b/src/dirfns.h
@@ -27,12 +27,12 @@
 
 #include <string>
 
-extern string polite_directory_format (const string&);
-extern string base_pathname (const string&);
-extern string make_absolute (const string&, const string&);
-extern string get_working_directory (const string&);
+extern std::string polite_directory_format (const std::string&);
+extern std::string base_pathname (const std::string&);
+extern std::string make_absolute (const std::string&, const std::string&);
+extern std::string get_working_directory (const std::string&);
 
-extern string Vcurrent_directory;
+extern std::string Vcurrent_directory;
 
 #endif
 
diff --git a/src/dynamic-ld.cc b/src/dynamic-ld.cc
--- a/src/dynamic-ld.cc
+++ b/src/dynamic-ld.cc
@@ -54,7 +54,7 @@
 
   static void remove (octave_shlib& shl);
 
-  static void *search (const string& fcn_name, octave_shlib& shl,
+  static void *search (const std::string& fcn_name, octave_shlib& shl,
 		       octave_shlib::name_mangler mangler = 0);
 
 private:
@@ -67,7 +67,7 @@
 
   void do_remove (octave_shlib& shl);
 
-  void *do_search (const string& fcn_name, octave_shlib& shl,
+  void *do_search (const std::string& fcn_name, octave_shlib& shl,
 		   octave_shlib::name_mangler mangler = 0);
 
   static octave_shlib_list *instance;
@@ -109,7 +109,7 @@
 }
 
 void *
-octave_shlib_list::do_search (const string& fcn_name, octave_shlib& shl,
+octave_shlib_list::do_search (const std::string& fcn_name, octave_shlib& shl,
 			      octave_shlib::name_mangler mangler)
 {
   void *function = 0;
@@ -164,7 +164,7 @@
 }
 
 void *
-octave_shlib_list::search (const string& fcn_name, octave_shlib& shl,
+octave_shlib_list::search (const std::string& fcn_name, octave_shlib& shl,
 			   octave_shlib::name_mangler mangler)
 {
   return (instance_ok ()) ? instance->do_search (fcn_name, shl, mangler) : 0;
@@ -193,7 +193,7 @@
 }
 
 static
-void clear_function (const string& fcn_name)
+void clear_function (const std::string& fcn_name)
 {
   if (Vwarn_reload_forces_clear)
     warning ("  %s", fcn_name.c_str ());
@@ -207,7 +207,7 @@
 }
 
 bool
-octave_dynamic_loader::do_load (const string& fcn_name)
+octave_dynamic_loader::do_load (const std::string& fcn_name)
 {
   bool retval = false;
 
@@ -239,7 +239,7 @@
 
       if (! function)
 	{
-	  string oct_file_name = oct_file_in_path (fcn_name);
+	  std::string oct_file_name = oct_file_in_path (fcn_name);
 
 	  if (! oct_file_name.empty ())
 	    {
@@ -278,7 +278,7 @@
 }
 
 bool
-octave_dynamic_loader::do_remove (const string& fcn_name, octave_shlib& shl)
+octave_dynamic_loader::do_remove (const std::string& fcn_name, octave_shlib& shl)
 {
   bool retval = false;
 
@@ -297,24 +297,24 @@
 }
 
 bool
-octave_dynamic_loader::load (const string& fcn_name)
+octave_dynamic_loader::load (const std::string& fcn_name)
 {
   return (instance_ok ()) ? instance->do_load (fcn_name) : false;
 }
 
 bool
-octave_dynamic_loader::remove (const string& fcn_name, octave_shlib& shl)
+octave_dynamic_loader::remove (const std::string& fcn_name, octave_shlib& shl)
 {
   return (instance_ok ()) ? instance->do_remove (fcn_name, shl) : false;
 }
 
 string
-octave_dynamic_loader::mangle_name (const string& name)
+octave_dynamic_loader::mangle_name (const std::string& name)
 {
 #if defined (CXX_PREPENDS_UNDERSCORE)
-  string retval ("_FS");
+  std::string retval ("_FS");
 #else
-  string retval ("FS");
+  std::string retval ("FS");
 #endif
   retval.append (name);
   retval.append ("__FRC12octave_shlib");
diff --git a/src/dynamic-ld.h b/src/dynamic-ld.h
--- a/src/dynamic-ld.h
+++ b/src/dynamic-ld.h
@@ -38,9 +38,9 @@
 
   virtual ~octave_dynamic_loader (void) { }
 
-  static bool load (const string& fcn_name);
+  static bool load (const std::string& fcn_name);
 
-  static bool remove (const string& fcn_name, octave_shlib& shl);
+  static bool remove (const std::string& fcn_name, octave_shlib& shl);
 
 private:
 
@@ -54,15 +54,15 @@
 
   static bool instance_ok (void);
 
-  bool do_load (const string& fcn_name);
+  bool do_load (const std::string& fcn_name);
 
-  bool do_remove (const string& fcn_name, octave_shlib& shl);
+  bool do_remove (const std::string& fcn_name, octave_shlib& shl);
 
   static bool doing_load;
 
 protected:
 
-  static string mangle_name (const string& name);
+  static std::string mangle_name (const std::string& name);
 };
 
 #endif
diff --git a/src/error.cc b/src/error.cc
--- a/src/error.cc
+++ b/src/error.cc
@@ -54,7 +54,7 @@
 bool buffer_error_messages = false;
 
 // The message buffer
-ostrstream *error_message_buffer = 0;
+std::ostrstream *error_message_buffer = 0;
 
 // Warning messages are never buffered.
 // XXX FIXME XXX -- we should provide another way to turn them off...
@@ -64,7 +64,7 @@
 {
   flush_octave_stdout ();
 
-  ostrstream output_buf;
+  std::ostrstream output_buf;
 
   if (name)
     {
@@ -86,7 +86,7 @@
 
   bool to_beep_or_not_to_beep_p = Vbeep_on_error && ! error_state;
 
-  ostrstream output_buf;
+  std::ostrstream output_buf;
 
   if (to_beep_or_not_to_beep_p)
     output_buf << "\a";
@@ -240,7 +240,7 @@
 {
   octave_value_list retval;
 
-  string tstr;
+  std::string tstr;
 
   int nargin = args.length ();
 
diff --git a/src/error.h b/src/error.h
--- a/src/error.h
+++ b/src/error.h
@@ -48,7 +48,7 @@
 extern bool buffer_error_messages;
 
 // The message buffer
-extern ostrstream *error_message_buffer;
+extern std::ostrstream *error_message_buffer;
 
 #endif
 
diff --git a/src/file-io.cc b/src/file-io.cc
--- a/src/file-io.cc
+++ b/src/file-io.cc
@@ -95,7 +95,7 @@
 }
 
 static int
-fopen_mode_to_ios_mode (const string& mode)
+fopen_mode_to_ios_mode (const std::string& mode)
 {
   int retval = 0;
 
@@ -241,7 +241,7 @@
 
 	  bool err = false;
 
-	  string tmp = os.getl (len_arg, err);
+	  std::string tmp = os.getl (len_arg, err);
 
 	  if (! err)
 	    {
@@ -287,7 +287,7 @@
 
 	  bool err = false;
 
-	  string tmp = os.gets (len_arg, err);
+	  std::string tmp = os.gets (len_arg, err);
 
 	  if (! err)
 	    {
@@ -303,8 +303,8 @@
 }
 
 static octave_stream
-do_stream_open (const string& name, const string& mode,
-		const string& arch, int& fid)
+do_stream_open (const std::string& name, const std::string& mode,
+		const std::string& arch, int& fid)
 {
   octave_stream retval;
 
@@ -332,15 +332,15 @@
 
   fid = -1;
 
-  string name = tc_name.string_value ();
+  std::string name = tc_name.string_value ();
 
   if (! error_state)
     {
-      string mode = tc_mode.string_value ();
+      std::string mode = tc_mode.string_value ();
 
       if (! error_state)
 	{
-	  string arch = tc_arch.string_value ();
+	  std::string arch = tc_arch.string_value ();
 
 	  if (! error_state)
 	    retval = do_stream_open (name, mode, arch, fid);
@@ -658,7 +658,7 @@
 	{
 	  if (args(fmt_n).is_string ())
 	    {
-	      string fmt = args(fmt_n).string_value ();
+	      std::string fmt = args(fmt_n).string_value ();
 
 	      octave_value_list tmp_args;
 
@@ -733,7 +733,7 @@
 	{
 	  if (args(0).is_string ())
 	    {
-	      string fmt = args(0).string_value ();
+	      std::string fmt = args(0).string_value ();
 
 	      octave_value_list tmp_args;
 
@@ -816,7 +816,7 @@
 	{
 	  if (args(1).is_string ())
 	    {
-	      string fmt = args(1).string_value ();
+	      std::string fmt = args(1).string_value ();
 
 	      retval = os.oscanf (fmt);
 	    }
@@ -837,7 +837,7 @@
 	    {
 	      if (args(1).is_string ())
 		{
-		  string fmt = args(1).string_value ();
+		  std::string fmt = args(1).string_value ();
 
 		  int count = 0;
 
@@ -880,7 +880,7 @@
     {
       if (args(0).is_string ())
 	{
-	  string data = args(0).string_value ();
+	  std::string data = args(0).string_value ();
 
 	  octave_stream os = octave_istrstream::create (data);
 
@@ -888,7 +888,7 @@
 	    {
 	      if (args(1).is_string ())
 		{
-		  string fmt = args(1).string_value ();
+		  std::string fmt = args(1).string_value ();
 
 		  retval = os.oscanf (fmt);
 		}
@@ -912,7 +912,7 @@
 
 	  if (args(0).is_string ())
 	    {
-	      string data = args(0).string_value ();
+	      std::string data = args(0).string_value ();
 
 	      octave_stream os = octave_istrstream::create (data);
 
@@ -920,7 +920,7 @@
 		{
 		  if (args(1).is_string ())
 		    {
-		      string fmt = args(1).string_value ();
+		      std::string fmt = args(1).string_value ();
 
 		      int count = 0;
 
@@ -932,7 +932,7 @@
 		      // XXX FIXME XXX -- is this the right thing to do?
 		      // Extract error message first, because getting
 		      // position will clear it.
-		      string errmsg = os.error ();
+		      std::string errmsg = os.error ();
 
 		      retval(3) = static_cast<double> (os.tell () + 1);
 		      retval(2) = errmsg;
@@ -989,7 +989,7 @@
 
   if (! error_state)
     {
-      string prec = prec_arg.string_value ();
+      std::string prec = prec_arg.string_value ();
 
       if (! error_state)
 	{
@@ -1002,7 +1002,7 @@
 
 	      if (! error_state)
 		{
-		  string arch = arch_arg.string_value ();
+		  std::string arch = arch_arg.string_value ();
 
 		  if (! error_state)
 		    {
@@ -1202,7 +1202,7 @@
 {
   int retval = -1;
 
-  string prec = prec_arg.string_value ();
+  std::string prec = prec_arg.string_value ();
 
   if (! error_state)
     {
@@ -1215,7 +1215,7 @@
 
 	  if (! error_state)
 	    {
-	      string arch = arch_arg.string_value ();
+	      std::string arch = arch_arg.string_value ();
 
 	      if (! error_state)
 		{
@@ -1338,7 +1338,7 @@
 
 	  if (nargin == 2)
 	    {
-	      string opt = args(1).string_value ();
+	      std::string opt = args(1).string_value ();
 
 	      if (! error_state)
 		clear = (opt == "clear");
@@ -1348,7 +1348,7 @@
 
 	  int error_number = 0;
 
-	  string error_message = os.error (clear, error_number);
+	  std::string error_message = os.error (clear, error_number);
 
 	  retval(1) = static_cast<double> (error_number);
 	  retval(0) = error_message;
@@ -1399,11 +1399,11 @@
 
   if (nargin == 2)
     {
-      string name = args(0).string_value ();
+      std::string name = args(0).string_value ();
 
       if (! error_state)
 	{
-	  string mode = args(1).string_value ();
+	  std::string mode = args(1).string_value ();
 
 	  if (! error_state)
 	    {
@@ -1470,8 +1470,8 @@
 
   if (len < 3)
     {
-      string dir = len > 0 ? args(0).string_value () : string ();
-      string pfx = len > 1 ? args(1).string_value () : string ("oct-");
+      std::string dir = len > 0 ? args(0).string_value () : std::string ();
+      std::string pfx = len > 1 ? args(1).string_value () : std::string ("oct-");
 
       if (! error_state)
 	retval = file_ops::tempnam (dir, pfx);
diff --git a/src/fn-cache.cc b/src/fn-cache.cc
--- a/src/fn-cache.cc
+++ b/src/fn-cache.cc
@@ -44,7 +44,7 @@
 // we don't delete any old ones.
 
 bool
-octave_fcn_file_name_cache::update (const string& path)
+octave_fcn_file_name_cache::update (const std::string& path)
 {
   bool something_changed = false;
 
@@ -56,7 +56,7 @@
 
   for (int i = 0; i < len; i++)
     {
-      string d = dirs[i];
+      std::string d = dirs[i];
 
       if (cache.contains (d))
 	{
@@ -74,7 +74,7 @@
 }
 
 string_vector
-octave_fcn_file_name_cache::list (const string& path, bool no_suffix)
+octave_fcn_file_name_cache::list (const std::string& path, bool no_suffix)
 {
   string_vector retval;
 
@@ -93,7 +93,7 @@
 // updated, then return the list of names in the cache.
 
 string_vector
-octave_fcn_file_name_cache::do_list (const string& path, bool no_suffix)
+octave_fcn_file_name_cache::do_list (const std::string& path, bool no_suffix)
 {
   update (path);
 
@@ -121,7 +121,7 @@
     {
       for (int i = 0; i < ndirs; i++)
 	{
-	  string d = dirs[i];
+	  std::string d = dirs[i];
 
 	  total_len += cache[d].length ();
 	}
@@ -133,7 +133,7 @@
 
       for (int j = 0; j < ndirs; j++)
 	{
-	  string d = dirs[j];
+	  std::string d = dirs[j];
 
 	  file_name_cache_elt elt = cache[d];
 
@@ -153,7 +153,7 @@
     }
   else if (ndirs == 1)
     {
-      string d = dirs[0];
+      std::string d = dirs[0];
 
       file_name_cache_elt elt = cache[d];
 
@@ -168,7 +168,7 @@
 // TRUE if the cache element was out of date.
 
 bool
-file_name_cache_elt::update (const string& dir_name)
+file_name_cache_elt::update (const std::string& dir_name)
 {
   bool retval = false;
 
@@ -200,7 +200,7 @@
 	      int i;
 	      for (i = 0; i < max_len; i++)
 		{
-		  string entry = tmp[i];
+		  std::string entry = tmp[i];
 
 		  int len = entry.length ();
 
@@ -218,8 +218,8 @@
 		      fcn_file_names[k] = entry;
 
 		      fcn_file_names_no_suffix[k] = (entry[len-1] == 'm')
-			? string (entry, 0, len-2)
-			: string (entry, 0, len-4);
+			? std::string (entry, 0, len-2)
+			: std::string (entry, 0, len-4);
 
 		      k++;
 		    }
diff --git a/src/fn-cache.h b/src/fn-cache.h
--- a/src/fn-cache.h
+++ b/src/fn-cache.h
@@ -42,9 +42,9 @@
   file_name_cache_elt (void)
     : timestamp (static_cast<time_t> (0)), fcn_file_names (),
       fcn_file_names_no_suffix ()
-  { update (string ()); }
+  { update (std::string ()); }
 
-  file_name_cache_elt (const string& dir_name)
+  file_name_cache_elt (const std::string& dir_name)
     : timestamp (static_cast<time_t> (0)), fcn_file_names (),
       fcn_file_names_no_suffix ()
   { update (dir_name); }
@@ -71,7 +71,7 @@
 
   int length (void) { return fcn_file_names.length (); }
 
-  bool update (const string& dir_name);
+  bool update (const std::string& dir_name);
 
   // The time we last read this directory.
   octave_time timestamp;
@@ -91,23 +91,23 @@
 
   octave_fcn_file_name_cache (void)
     : cache (file_name_cache_elt ())
-  { update (string ()); }
+  { update (std::string ()); }
 
 public:
 
   ~octave_fcn_file_name_cache (void) { }
 
-  bool update (const string& path);
+  bool update (const std::string& path);
 
   static string_vector list (bool no_suffix = false)
-    { return list (string (), no_suffix); }
+    { return list (std::string (), no_suffix); }
 
-  static string_vector list (const string& path, bool no_suffix = false);
+  static string_vector list (const std::string& path, bool no_suffix = false);
 
   static string_vector list_no_suffix (void)
     { return list (true); }
 
-  static string_vector list_no_suffix (const string& path)
+  static string_vector list_no_suffix (const std::string& path)
     { return list (path, true); }
 
 private:
@@ -118,7 +118,7 @@
   // and the corresponding cache elements.
   CHMap<file_name_cache_elt> cache;
 
-  string_vector do_list (const string& path, bool no_suffix);
+  string_vector do_list (const std::string& path, bool no_suffix);
 };
 
 #endif
diff --git a/src/gripes.cc b/src/gripes.cc
--- a/src/gripes.cc
+++ b/src/gripes.cc
@@ -37,7 +37,7 @@
 void
 gripe_string_invalid (void)
 {
-  error ("string constant used in invalid context");
+  error ("std::string constant used in invalid context");
 }
 
 void
@@ -87,7 +87,7 @@
 }
 
 void
-gripe_invalid_conversion (const string& from, const string& to)
+gripe_invalid_conversion (const std::string& from, const std::string& to)
 {
   error ("invalid conversion from %s to %s", from.c_str (), to.c_str ());
 }
@@ -123,7 +123,7 @@
 }
 
 void
-gripe_wrong_type_arg (const char *name, const string& s, bool is_error)
+gripe_wrong_type_arg (const char *name, const std::string& s, bool is_error)
 {
   if (is_error)
     error ("%s: wrong type argument `%s'", name, s.c_str ());
@@ -135,7 +135,7 @@
 gripe_wrong_type_arg (const char *name, const octave_value& tc,
 		      bool is_error)
 {
-  string type = tc.type_name ();
+  std::string type = tc.type_name ();
 
   if (is_error)
     error ("%s: wrong type argument `%s'", name, type.c_str ());
@@ -146,14 +146,14 @@
 void
 gripe_wrong_type_arg_for_unary_op (const octave_value& op)
 {
-  string type = op.type_name ();
+  std::string type = op.type_name ();
   error ("invalid operand `%s' for unary operator", type.c_str ());
 }
 
 void
 gripe_wrong_type_arg_for_binary_op (const octave_value& op)
 {
-  string type = op.type_name ();
+  std::string type = op.type_name ();
   error ("invalid operand `%s' for binary operator", type.c_str ());
 }
 
diff --git a/src/gripes.h b/src/gripes.h
--- a/src/gripes.h
+++ b/src/gripes.h
@@ -55,7 +55,7 @@
 gripe_user_returned_invalid (const char *name);
 
 extern void
-gripe_invalid_conversion (const string& from, const string& to);
+gripe_invalid_conversion (const std::string& from, const std::string& to);
 
 extern void
 gripe_invalid_value_specified (const char *name);
@@ -73,7 +73,7 @@
 gripe_data_conversion (const char *from, const char *to);
 
 extern void
-gripe_wrong_type_arg (const char *name, const string& s,
+gripe_wrong_type_arg (const char *name, const std::string& s,
 		      bool is_error = true);
 
 extern void
diff --git a/src/help.cc b/src/help.cc
--- a/src/help.cc
+++ b/src/help.cc
@@ -70,11 +70,11 @@
 
 // Name of the info file specified on command line.
 // (--info-file file)
-string Vinfo_file;
+std::string Vinfo_file;
 
 // Name of the info reader we'd like to use.
 // (--info-program program)
-string Vinfo_prog;
+std::string Vinfo_prog;
 
 // If TRUE, don't print additional help message in help and usage
 // functions.
@@ -387,7 +387,7 @@
 }
 
 void
-additional_help_message (ostream& os)
+additional_help_message (std::ostream& os)
 {
   if (! Vsuppress_verbose_help_message)
     os << "\n\
@@ -404,7 +404,7 @@
 // symbol table stuff.
 
 static void
-display_names_from_help_list (ostream& os, help_list *list,
+display_names_from_help_list (std::ostream& os, help_list *list,
 			      const char *desc)
 {
   string_vector symbols = names (list);
@@ -420,8 +420,8 @@
 }
 
 static void
-display_symtab_names (ostream& os, const string_vector& names,
-		      const string& desc)
+display_symtab_names (std::ostream& os, const string_vector& names,
+		      const std::string& desc)
 {
   if (! names.empty ())
     {
@@ -483,7 +483,7 @@
 
       if (! names.empty ())
 	{
-	  string dir
+	  std::string dir
 	    = octave_env::make_absolute (dirs[i], octave_env::getcwd ());
 
 	  octave_stdout << "\n*** function files in " << dir << ":\n\n";
@@ -496,7 +496,7 @@
 }
 
 static int
-try_info (const string& nm)
+try_info (const std::string& nm)
 {
   int status = 0;
 
@@ -505,11 +505,11 @@
   delete [] cmd_str;
   cmd_str = 0;
 
-  ostrstream cmd_buf;
+  std::ostrstream cmd_buf;
 
   cmd_buf << Vinfo_prog << " --file " << Vinfo_file;
 
-  string directory_name = Vinfo_file;
+  std::string directory_name = Vinfo_file;
   size_t pos = directory_name.rfind ('/');
 
   if (pos != NPOS)
@@ -544,7 +544,7 @@
 help_from_info (const string_vector& argv, int idx, int argc)
 {
   if (idx == argc)
-    try_info (string ());
+    try_info (std::string ());
   else
     {
       for (int i = idx; i < argc; i++)
@@ -570,11 +570,11 @@
 }
 
 static bool
-looks_like_texinfo (const string& msg, size_t& p1)
+looks_like_texinfo (const std::string& msg, size_t& p1)
 {
   p1 = msg.find ('\n');
 
-  string t = msg.substr (0, p1);
+  std::string t = msg.substr (0, p1);
 
   if (p1 == NPOS)
     p1 = 0;
@@ -585,7 +585,7 @@
 }
 
 void
-display_help_text (ostream& os, const string& msg)
+display_help_text (std::ostream& os, const std::string& msg)
 {
   // Look for "-*- texinfo -*-" in first line of help message.  If it
   // is present, use makeinfo to format the rest of the message before
@@ -596,7 +596,7 @@
 
   if (looks_like_texinfo (msg, pos))
     {
-      string tmp_file_name = file_ops::tempnam ("", "");
+      std::string tmp_file_name = file_ops::tempnam ("", "");
 
       int cols = command_editor::terminal_cols ();
 
@@ -609,7 +609,7 @@
       if (cols > 80)
 	cols = 72;
 
-      ostrstream buf;
+      std::ostrstream buf;
       buf << "sed -e 's/^[#%]+ *//' -e 's/^ *@/@/' | makeinfo"
 	  << " -D \"VERSION " << OCTAVE_VERSION << "\""
 	  << " -D \"OCTAVEHOME " << OCTAVE_PREFIX << "\""
@@ -641,7 +641,7 @@
 
 	  filter.close ();
 
-	  ifstream tmp_file (tmp_file_name.c_str ());
+	  std::ifstream tmp_file (tmp_file_name.c_str ());
 
 	  int c;
 	  while ((c = tmp_file.get ()) != EOF)
@@ -659,8 +659,8 @@
 }
 
 static bool
-help_from_list (ostream& os, const help_list *list,
-		const string& nm, int usage)
+help_from_list (std::ostream& os, const help_list *list,
+		const std::string& nm, int usage)
 {
   const char *name;
 
@@ -688,7 +688,7 @@
 }
 
 static bool
-help_from_symbol_table (ostream& os, const string& nm)
+help_from_symbol_table (std::ostream& os, const std::string& nm)
 {
   bool retval = false;
 
@@ -696,7 +696,7 @@
 
   if (sym_rec && sym_rec->is_defined ())
     {
-      string h = sym_rec->help ();
+      std::string h = sym_rec->help ();
 
       if (h.length () > 0)
 	{
@@ -712,13 +712,13 @@
 }
 
 static bool
-help_from_file (ostream& os, const string& nm)
+help_from_file (std::ostream& os, const std::string& nm)
 {
   bool retval = false;
 
-  string path = fcn_file_in_path (nm);
+  std::string path = fcn_file_in_path (nm);
 
-  string h = get_help_from_file (path);
+  std::string h = get_help_from_file (path);
 
   if (! h.empty ())
     {
@@ -800,7 +800,7 @@
 }
 
 static void
-do_type (ostream& os, const string& name, bool pr_type_info,
+do_type (std::ostream& os, const std::string& name, bool pr_type_info,
 	 bool quiet, bool pr_orig_txt)
 {
   symbol_record *sym_rec = lookup_by_name (name, 0);
@@ -809,11 +809,11 @@
     sym_rec->type (os, pr_type_info, quiet, pr_orig_txt);
   else
     {
-      string ff = fcn_file_in_path (name);
+      std::string ff = fcn_file_in_path (name);
 
       if (! ff.empty ())
 	{
-	  ifstream fs (ff.c_str (), ios::in);
+	  std::ifstream fs (ff.c_str (), ios::in);
 
 	  if (fs)
 	    {
@@ -882,11 +882,11 @@
 
 	  if (idx < argc)
 	    {
-	      ostrstream output_buf;
+	      std::ostrstream output_buf;
 
 	      for (int i = idx; i < argc; i++)
 		{
-		  string id = argv[i];
+		  std::string id = argv[i];
 
 		  if (nargout == 0)
 		    do_type (octave_stdout, id, true, quiet, pr_orig_txt);
@@ -921,9 +921,9 @@
 }
 
 static string
-do_which (const string& name)
+do_which (const std::string& name)
 {
-  string retval;
+  std::string retval;
 
   symbol_record *sym_rec = lookup_by_name (name, 0);
 
@@ -931,7 +931,7 @@
     retval = sym_rec->which ();
   else
     {
-      string path = fcn_file_in_path (name);
+      std::string path = fcn_file_in_path (name);
 
       if (! path.empty ())
 	retval = path;
@@ -943,7 +943,7 @@
 }
 
 static void
-do_which (ostream& os, const string& name)
+do_which (std::ostream& os, const std::string& name)
 {
   symbol_record *sym_rec = lookup_by_name (name, 0);
 
@@ -951,7 +951,7 @@
     sym_rec->which (os);
   else
     {
-      string path = fcn_file_in_path (name);
+      std::string path = fcn_file_in_path (name);
 
       if (! path.empty ())
 	os << "which: `" << name << "' is the script file\n"
@@ -983,7 +983,7 @@
 	{
 	  for (int i = 1; i < argc; i++)
 	    {
-	      string id = argv[i];
+	      std::string id = argv[i];
 
 	      if (nargout == 0)
 		do_which (octave_stdout, id);
@@ -1003,7 +1003,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("INFO_FILE");
+  std::string s = builtin_string_variable ("INFO_FILE");
 
   if (s.empty ())
     {
@@ -1021,7 +1021,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("INFO_PROGRAM");
+  std::string s = builtin_string_variable ("INFO_PROGRAM");
 
   if (s.empty ())
     {
diff --git a/src/help.h b/src/help.h
--- a/src/help.h
+++ b/src/help.h
@@ -30,17 +30,17 @@
 
 extern string_vector make_name_list (void);
 
-extern void display_help_text (ostream&, const string&);
+extern void display_help_text (std::ostream&, const std::string&);
 
-extern void additional_help_message (ostream&);
+extern void additional_help_message (std::ostream&);
 
 // Name of the info file specified on command line.
 // (--info-file file)
-extern string Vinfo_file;
+extern std::string Vinfo_file;
 
 // Name of the info reader we'd like to use.
 // (--info-program program)
-extern string Vinfo_prog;
+extern std::string Vinfo_prog;
 
 #endif
 
diff --git a/src/input.cc b/src/input.cc
--- a/src/input.cc
+++ b/src/input.cc
@@ -68,13 +68,13 @@
 #include "variables.h"
 
 // Primary prompt string.
-static string Vps1;
+static std::string Vps1;
 
 // Secondary prompt string.
-static string Vps2;
+static std::string Vps2;
 
 // String printed before echoed input (enabled by --echo-input).
-string Vps4;
+std::string Vps4;
 
 // Echo commands as they are executed?
 //
@@ -92,7 +92,7 @@
 static char Vcompletion_append_char;
 
 // Global pointer for eval().
-string current_eval_string;
+std::string current_eval_string;
 
 // TRUE means get input from current_eval_string.
 bool get_input_from_eval_string = false;
@@ -101,10 +101,10 @@
 bool reading_fcn_file = false;
 
 // Simple name of function file we are reading.
-string curr_fcn_file_name;
+std::string curr_fcn_file_name;
 
 // Full name of file we are reading.
-string curr_fcn_file_full_name;
+std::string curr_fcn_file_full_name;
 
 // TRUE means we're parsing a script file.
 bool reading_script_file = false;
@@ -122,13 +122,13 @@
 int promptflag = 1;
 
 // The current line of input, from wherever.
-string current_input_line;
+std::string current_input_line;
 
 // TRUE after a call to completion_matches().
 bool octave_completion_matches_called = false;
 
 static void
-do_input_echo (const string& input_string)
+do_input_echo (const std::string& input_string)
 {
   int do_echo = reading_script_file ?
     (Vecho_executing_commands & ECHO_SCRIPTS)
@@ -157,9 +157,9 @@
 }
 
 string
-gnu_readline (const string& s, bool force_readline)
+gnu_readline (const std::string& s, bool force_readline)
 {
-  string retval;
+  std::string retval;
 
   if (line_editing || force_readline)
     {
@@ -194,16 +194,16 @@
 static string
 octave_gets (void)
 {
-  string retval;
+  std::string retval;
 
   Vlast_prompt_time.stamp ();
 
   if ((interactive || forced_interactive)
       && (! (reading_fcn_file || reading_script_file)))
     {
-      string ps = (promptflag > 0) ? Vps1 : Vps2;
+      std::string ps = (promptflag > 0) ? Vps1 : Vps2;
 
-      string prompt = command_editor::decode_prompt_string (ps);
+      std::string prompt = command_editor::decode_prompt_string (ps);
 
       pipe_handler_error_count = 0;
 
@@ -244,7 +244,7 @@
 static string
 get_user_input (void)
 {
-  string retval;
+  std::string retval;
 
   if (get_input_from_eval_string)
     {
@@ -271,7 +271,7 @@
 {
   // XXX FIXME XXX -- is this a safe way to buffer the input?
 
-  static string input_buf;
+  static std::string input_buf;
   static const char *pos = 0;
   static size_t chars_left = 0;
 
@@ -338,7 +338,7 @@
 // warning if the file doesn't exist.
 
 FILE *
-get_input_from_file (const string& name, int warn)
+get_input_from_file (const std::string& name, int warn)
 {
   FILE *instream = 0;
 
@@ -370,8 +370,8 @@
 // XXX FIXME XXX -- make this generate file names when appropriate.
 
 static string_vector
-generate_possible_completions (const string& text, string& prefix,
-			       string& hint)
+generate_possible_completions (const std::string& text, std::string& prefix,
+			       std::string& hint)
 {
   string_vector names;
 
@@ -390,12 +390,12 @@
 }
 
 static string
-generate_completion (const string& text, int state)
+generate_completion (const std::string& text, int state)
 {
-  string retval;
+  std::string retval;
 
-  static string prefix;
-  static string hint;
+  static std::string prefix;
+  static std::string hint;
 
   static size_t prefix_len = 0;
   static size_t hint_len = 0;
@@ -433,7 +433,7 @@
     {
       while (list_index < name_list_len)
 	{
-	  string name = name_list[list_index];
+	  std::string name = name_list[list_index];
 
 	  list_index++;
 
@@ -472,7 +472,7 @@
 }
 
 static bool
-match_sans_spaces (const string& standard, const string& test)
+match_sans_spaces (const std::string& standard, const std::string& test)
 {
   size_t beg = test.find_first_not_of (" \t");
 
@@ -502,7 +502,7 @@
   if (nargin == 2)
     read_as_string++;
 
-  string prompt ("debug> ");
+  std::string prompt ("debug> ");
 
   if (nargin > 0)
    {
@@ -519,7 +519,7 @@
 
   flush_octave_stdout ();
 
-  string input_buf = gnu_readline (prompt.c_str (), true);
+  std::string input_buf = gnu_readline (prompt.c_str (), true);
 
   if (! input_buf.empty ())
     {
@@ -737,7 +737,7 @@
 
     case 2:
       {
-	string arg = argv[1];
+	std::string arg = argv[1];
 
 	if (arg == "on")
 	  bind_builtin_variable ("echo_executing_commands",
@@ -752,7 +752,7 @@
 
     case 3:
       {
-	string arg = argv[1];
+	std::string arg = argv[1];
 
 	if (arg == "on" && argv[2] == "all")
 	  {
@@ -793,7 +793,7 @@
 
   if (nargin == 1)
     {
-      string hint = args(0).string_value ();
+      std::string hint = args(0).string_value ();
 
       if (! error_state)
 	{
@@ -805,7 +805,7 @@
 
 	  for (;;)
 	    {
-	      string cmd = generate_completion (hint, k);
+	      std::string cmd = generate_completion (hint, k);
 
 	      if (! cmd.empty ())
 		{
@@ -868,7 +868,7 @@
     command_editor::read_init_file ();
   else if (nargin == 1)
     {
-      string file = file_ops::tilde_expand (args(0).string_value ());
+      std::string file = file_ops::tilde_expand (args(0).string_value ());
 
       if (! error_state)
 	command_editor::read_init_file (file);
@@ -879,7 +879,7 @@
   return retval;
 }
 
-static string hook_fcn;
+static std::string hook_fcn;
 static octave_value user_data;
 
 static void
@@ -917,7 +917,7 @@
     {
       octave_value tmp_user_data;
 
-      string tmp_hook_fcn;
+      std::string tmp_hook_fcn;
 
       if (nargin > 1)
 	tmp_user_data = args(1);
@@ -983,7 +983,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("completion_append_char");
+  std::string s = builtin_string_variable ("completion_append_char");
 
   switch (s.length ())
     {
diff --git a/src/input.h b/src/input.h
--- a/src/input.h
+++ b/src/input.h
@@ -32,11 +32,11 @@
 #include "oct-time.h"
 
 extern int octave_read (char *buf, unsigned max_size);
-extern FILE *get_input_from_file (const string& name, int warn = 1);
+extern FILE *get_input_from_file (const std::string& name, int warn = 1);
 extern FILE *get_input_from_stdin (void);
 
 // Global pointer for eval().
-extern string current_eval_string;
+extern std::string current_eval_string;
 
 // TRUE means get input from current_eval_string.
 extern bool get_input_from_eval_string;
@@ -45,10 +45,10 @@
 extern bool reading_fcn_file;
 
 // Simple name of function file we are reading.
-extern string curr_fcn_file_name;
+extern std::string curr_fcn_file_name;
 
 // Full name of file we are reading.
-extern string curr_fcn_file_full_name;
+extern std::string curr_fcn_file_full_name;
 
 // TRUE means we're parsing a script file.
 extern bool reading_script_file;
@@ -66,16 +66,16 @@
 extern int promptflag;
 
 // A line of input.
-extern string current_input_line;
+extern std::string current_input_line;
 
 // TRUE after a call to completion_matches().
 extern bool octave_completion_matches_called;
 
-extern string gnu_readline (const string& s, bool force_readline = false);
+extern std::string gnu_readline (const std::string& s, bool force_readline = false);
 
 extern void initialize_command_input (void);
 
-extern string Vps4;
+extern std::string Vps4;
 
 enum echo_state
 {
diff --git a/src/lex.l b/src/lex.l
--- a/src/lex.l
+++ b/src/lex.l
@@ -171,20 +171,20 @@
 
 static void fixup_column_count (char *s);
 static void do_comma_insert_check (void);
-static int is_plot_keyword (const string& s);
-static int is_keyword (const string& s);
-static string plot_style_token (const string& s);
-static symbol_record *lookup_identifier (const string& s);
+static int is_plot_keyword (const std::string& s);
+static int is_keyword (const std::string& s);
+static std::string plot_style_token (const std::string& s);
+static symbol_record *lookup_identifier (const std::string& s);
 static void grab_help_text (void);
 static bool match_any (char c, const char *s);
 static bool next_token_is_sep_op (void);
 static bool next_token_is_bin_op (bool spc_prev);
 static bool next_token_is_postfix_unary_op (bool spc_prev);
-static string strip_trailing_whitespace (char *s);
+static std::string strip_trailing_whitespace (char *s);
 static void handle_number (void);
 static int handle_string (char delim, int text_style = 0);
 static int handle_close_bracket (int spc_gobbled);
-static int handle_identifier (const string& tok, int spc_gobbled);
+static int handle_identifier (const std::string& tok, int spc_gobbled);
 static bool have_continuation (bool trailing_comments_ok = true);
 static bool have_ellipsis_continuation (bool trailing_comments_ok = true);
 static yum_yum eat_whitespace (void);
@@ -250,7 +250,7 @@
   }
 
 <TEXT_FCN>[^ \t\n\;\,\"\'][^ \t\n\;\,]*{S}* {
-    string tok = strip_trailing_whitespace (yytext);
+    std::string tok = strip_trailing_whitespace (yytext);
     TOK_PUSH_AND_RETURN (tok, TEXT);
   }
 
@@ -488,7 +488,7 @@
 %}
 
 {IDENT}{S}* {
-    string tok = strip_trailing_whitespace (yytext);
+    std::string tok = strip_trailing_whitespace (yytext);
     int c = yytext[yyleng-1];
     int cont_is_spc = eat_continuation ();
     int spc_gobbled = (cont_is_spc || c == ' ' || c == '\t');
@@ -851,9 +851,9 @@
 // styles for plots.
 
 static string
-plot_style_token (const string& s)
+plot_style_token (const std::string& s)
 {
-  string retval;
+  std::string retval;
 
   static const char *plot_styles[] = 
     {
@@ -897,9 +897,9 @@
 // tags for plots.
 
 static string
-plot_axes_token (const string& s)
+plot_axes_token (const std::string& s)
 {
-  string retval;
+  std::string retval;
 
   static char *plot_axes[] = 
     {
@@ -931,7 +931,7 @@
 // to abbreviate actual gnuplot keywords).
 
 static int
-is_plot_keyword (const string& s)
+is_plot_keyword (const std::string& s)
 {
   const char *t = s.c_str ();
   if (almost_match ("title", t))
@@ -966,13 +966,13 @@
 // Handle keywords.
 
 static int
-is_keyword (const string& s)
+is_keyword (const std::string& s)
 {
   if (lexer_flags.plotting)
     {
       if (lexer_flags.in_plot_style)
 	{
-	  string sty = plot_style_token (s);
+	  std::string sty = plot_style_token (s);
 
 	  if (! sty.empty ())
 	    {
@@ -984,7 +984,7 @@
 	}
       else if (lexer_flags.in_plot_axes)
 	{
-	  string axes = plot_axes_token (s);
+	  std::string axes = plot_axes_token (s);
 
 	  if (! axes.empty ())
 	    {
@@ -1150,13 +1150,13 @@
 // variables occurs when expressions are evaluated.
 
 static symbol_record *
-lookup_identifier (const string& name)
+lookup_identifier (const std::string& name)
 {
   return curr_sym_tab->lookup (name, true);
 }
 
 static bool
-is_variable (const string& name)
+is_variable (const std::string& name)
 {
   symbol_record *sr = curr_sym_tab->lookup (name);
 
@@ -1164,7 +1164,7 @@
 }
 
 static void
-force_local_variable (const string& name)
+force_local_variable (const std::string& name)
 {
   symbol_record *sr = curr_sym_tab->lookup (name, true);
 
@@ -1447,7 +1447,7 @@
 static string
 strip_trailing_whitespace (char *s)
 {
-  string retval = s;
+  std::string retval = s;
 
   size_t pos = retval.find_first_of (" \t");
 
@@ -1592,7 +1592,7 @@
 static bool
 have_continuation (bool trailing_comments_ok)
 {
-  ostrstream buf;
+  std::ostrstream buf;
 
   bool in_comment = false;
   int c;
@@ -1701,7 +1701,7 @@
 static int
 handle_string (char delim, int text_style)
 {
-  ostrstream buf;
+  std::ostrstream buf;
 
   int c;
   int escape_pending = 0;
@@ -1753,12 +1753,12 @@
 		  unput (c);
 		  buf << ends;
 		  char *t = buf.str ();
-		  string s = do_string_escapes (t);
+		  std::string s = do_string_escapes (t);
 		  delete [] t;
 
 		  if (text_style && lexer_flags.doing_set)
 		    {
-		      s = string (1, delim) + s + string (1, delim);
+		      s = std::string (1, delim) + s + std::string (1, delim);
 		    }
 		  else
 		    {
@@ -1977,7 +1977,7 @@
 // an identifier.  Handles keywords.
 
 static int
-handle_identifier (const string& tok, int spc_gobbled)
+handle_identifier (const std::string& tok, int spc_gobbled)
 {
   // It is almost always an error for an identifier to be followed
   // directly by another identifier.  Special cases are handled
@@ -2233,7 +2233,7 @@
 static void
 maybe_warn_separator_insert (char sep)
 {
-  string nm = curr_fcn_file_full_name;
+  std::string nm = curr_fcn_file_full_name;
 
   if (Vwarn_separator_insert)
     {
@@ -2249,7 +2249,7 @@
 static void
 gripe_single_quote_string (void)
 {
-  string nm = curr_fcn_file_full_name;
+  std::string nm = curr_fcn_file_full_name;
 
   if (Vwarn_single_quote_string)
     {
@@ -2283,7 +2283,7 @@
 {
   int pref = 0;
 
-  string val = builtin_string_variable ("whitespace_in_literal_matrix");
+  std::string val = builtin_string_variable ("whitespace_in_literal_matrix");
 
   if (! val.empty ())
     {
diff --git a/src/load-save.cc b/src/load-save.cc
--- a/src/load-save.cc
+++ b/src/load-save.cc
@@ -63,7 +63,7 @@
 
 // The default output format.  May be one of "binary", "text", or
 // "mat-binary".
-static string Vdefault_save_format;
+static std::string Vdefault_save_format;
 
 // The number of decimal digits to use when writing ascii data.
 static int Vsave_precision;
@@ -99,7 +99,7 @@
 }
 
 static bool
-valid_identifier (const string& s)
+valid_identifier (const std::string& s)
 {
   return valid_identifier (s.c_str ());
 }
@@ -248,7 +248,7 @@
 // Skip white space and comments on stream IS.
 
 static void
-skip_comments (istream& is)
+skip_comments (std::istream& is)
 {
   char c = '\0';
   while (is.get (c))
@@ -277,7 +277,7 @@
 //  #[ \t]*keyword[ \t]*:[ \t]*string-value[ \t]*\n
 
 static char *
-extract_keyword (istream& is, const char *keyword)
+extract_keyword (std::istream& is, const char *keyword)
 {
   char *retval = 0;
 
@@ -286,7 +286,7 @@
     {
       if (c == '#')
 	{
-	  ostrstream buf;
+	  std::ostrstream buf;
 	
 	  while (is.get (c) && (c == ' ' || c == '\t' || c == '#'))
 	    ; // Skip whitespace and comment characters.
@@ -304,7 +304,7 @@
 
 	  if (match)
 	    {
-	      ostrstream value;
+	      std::ostrstream value;
 	      while (is.get (c) && (c == ' ' || c == '\t' || c == ':'))
 		; // Skip whitespace and the colon.
 
@@ -344,7 +344,7 @@
 //  [ \t]*keyword[ \t]*int-value.*\n
 
 static bool
-extract_keyword (istream& is, const char *keyword, int& value)
+extract_keyword (std::istream& is, const char *keyword, int& value)
 {
   bool status = false;
   value = 0;
@@ -354,7 +354,7 @@
     {
       if (c == '#')
 	{
-	  ostrstream buf;
+	  std::ostrstream buf;
 
 	  while (is.get (c) && (c == ' ' || c == '\t' || c == '#'))
 	    ; // Skip whitespace and comment characters.
@@ -468,7 +468,7 @@
 // arbitrary comments, etc.  Someone should fix that.
 
 static char *
-read_ascii_data (istream& is, const string& filename, bool& global,
+read_ascii_data (std::istream& is, const std::string& filename, bool& global,
 		 octave_value& tc, int count)
 {
   // Read name for this entry or break on EOF.
@@ -739,9 +739,9 @@
 // FILENAME is used for error messages.
 
 static char *
-read_binary_data (istream& is, bool swap,
+read_binary_data (std::istream& is, bool swap,
 		  oct_mach_info::float_format fmt,
-		  const string& filename, bool& global,
+		  const std::string& filename, bool& global,
 		  octave_value& tc, char *&doc)
 {
   char tmp = 0;
@@ -946,9 +946,9 @@
 }
 
 static string
-get_mat_data_input_line (istream& is)
+get_mat_data_input_line (std::istream& is)
 {
-  string retval;
+  std::string retval;
 
   bool have_data = false;
 
@@ -986,7 +986,7 @@
 }
 
 static void
-get_lines_and_columns (istream& is, const string& filename, int& nr, int& nc)
+get_lines_and_columns (std::istream& is, const std::string& filename, int& nr, int& nc)
 {
   streampos pos = is.tellg ();
 
@@ -997,7 +997,7 @@
 
   while (is && ! error_state)
     {
-      string buf = get_mat_data_input_line (is);
+      std::string buf = get_mat_data_input_line (is);
 
       file_line_number++;
 
@@ -1051,12 +1051,12 @@
 // This format provides no way to tag the data as global.
 
 static char *
-read_mat_ascii_data (istream& is, const string& filename,
+read_mat_ascii_data (std::istream& is, const std::string& filename,
 		     octave_value& tc)
 {
   char *name = 0;
 
-  string varname;
+  std::string varname;
 
   size_t pos = filename.rfind ('/');
 
@@ -1088,9 +1088,9 @@
 	      double d;
 	      for (int i = 0; i < nr; i++)
 		{
-		  string buf = get_mat_data_input_line (is);
-
-		  istrstream tmp_stream (buf.c_str ());
+		  std::string buf = get_mat_data_input_line (is);
+
+		  std::istrstream tmp_stream (buf.c_str ());
 
 		  for (int j = 0; j < nc; j++)
 		    {
@@ -1138,7 +1138,7 @@
 // numbers.
 
 static void
-read_mat_binary_data (istream& is, double *data, int precision,
+read_mat_binary_data (std::istream& is, double *data, int precision,
 		      int len, bool swap,
 		      oct_mach_info::float_format flt_fmt)
 {
@@ -1174,7 +1174,7 @@
 }
 
 static int
-read_mat_file_header (istream& is, bool& swap, FOUR_BYTE_INT& mopt, 
+read_mat_file_header (std::istream& is, bool& swap, FOUR_BYTE_INT& mopt, 
 		      FOUR_BYTE_INT& nr, FOUR_BYTE_INT& nc,
 		      FOUR_BYTE_INT& imag, FOUR_BYTE_INT& len,
 		      int quiet = 0)
@@ -1323,7 +1323,7 @@
 // This format provides no way to tag the data as global.
 
 static char *
-read_mat_binary_data (istream& is, const string& filename,
+read_mat_binary_data (std::istream& is, const std::string& filename,
 		      octave_value& tc)
 {
   // These are initialized here instead of closer to where they are
@@ -1447,7 +1447,7 @@
 
 static bool
 matches_patterns (const string_vector& patterns, int pat_idx,
-		  int num_pat, const string& name)
+		  int num_pat, const std::string& name)
 {
   for (int i = pat_idx; i < num_pat; i++)
     {
@@ -1460,7 +1460,7 @@
 }
 
 static int
-read_binary_file_header (istream& is, bool& swap,
+read_binary_file_header (std::istream& is, bool& swap,
 			 oct_mach_info::float_format& flt_fmt,
 			 bool quiet = false)
 {
@@ -1495,11 +1495,11 @@
 }
 
 static load_save_format
-get_file_format (const string& fname, const string& orig_fname)
+get_file_format (const std::string& fname, const std::string& orig_fname)
 {
   load_save_format retval = LS_UNKNOWN;
 
-  ifstream file (fname.c_str ());
+  std::ifstream file (fname.c_str ());
 
   if (! file)
     {
@@ -1560,14 +1560,14 @@
 }
 
 static octave_value_list
-do_load (istream& stream, const string& orig_fname, bool force,
+do_load (std::istream& stream, const std::string& orig_fname, bool force,
 	 load_save_format format, oct_mach_info::float_format flt_fmt,
 	 bool list_only, bool swap, bool verbose, const string_vector& argv,
 	 int argv_idx, int argc, int nargout)
 {
   octave_value_list retval;
 
-  ostrstream output_buf;
+  std::ostrstream output_buf;
   int count = 0;
   for (;;)
     {
@@ -1790,7 +1790,7 @@
       return retval;
     }
 
-  string orig_fname = argv[i];
+  std::string orig_fname = argv[i];
 
   oct_mach_info::float_format flt_fmt = oct_mach_info::unknown;
 
@@ -1816,7 +1816,7 @@
     }
   else
     {
-      string fname = file_ops::tilde_expand (argv[i]);
+      std::string fname = file_ops::tilde_expand (argv[i]);
 
       if (format == LS_UNKNOWN)
 	format = get_file_format (fname, orig_fname);
@@ -1829,7 +1829,7 @@
 	  if (format == LS_BINARY || format == LS_MAT_BINARY)
 	    mode |= ios::bin;
 
-	  ifstream file (fname.c_str (), mode);
+	  std::ifstream file (fname.c_str (), mode);
 
 	  if (file)
 	    {
@@ -1860,7 +1860,7 @@
 // Return TRUE if PATTERN has any special globbing chars in it.
 
 static bool
-glob_pattern_p (const string& pattern)
+glob_pattern_p (const std::string& pattern)
 {
   int open = 0;
 
@@ -1926,8 +1926,8 @@
 // binary format described above for read_binary_data.
 
 static bool
-save_binary_data (ostream& os, const octave_value& tc,
-		  const string& name, const string& doc,
+save_binary_data (std::ostream& os, const octave_value& tc,
+		  const std::string& name, const std::string& doc,
 		  bool mark_as_global, bool save_as_floats) 
 {
   FOUR_BYTE_INT name_len = name.length ();
@@ -1956,7 +1956,7 @@
 	{
 	  FOUR_BYTE_INT len = chm.cols ();
 	  os.write (&len, 4);
-	  string tstr = chm.row_as_string (i);
+	  std::string tstr = chm.row_as_string (i);
 	  const char *tmp = tstr.data ();
 	  os.write (tmp, len);
 	}
@@ -2063,8 +2063,8 @@
 // in the MatLab binary format.
 
 static bool
-save_mat_binary_data (ostream& os, const octave_value& tc,
-		      const string& name) 
+save_mat_binary_data (std::ostream& os, const octave_value& tc,
+		      const std::string& name) 
 {
   FOUR_BYTE_INT mopt = 0;
 
@@ -2147,7 +2147,7 @@
 }
 
 static void
-ascii_save_type (ostream& os, const char *type, bool mark_as_global)
+ascii_save_type (std::ostream& os, const char *type, bool mark_as_global)
 {
   if (mark_as_global)
     os << "# type: global ";
@@ -2243,8 +2243,8 @@
 // XXX FIXME XXX -- should probably write the help string here too.
 
 bool
-save_ascii_data (ostream& os, const octave_value& tc,
-		 const string& name, bool strip_nan_and_inf,
+save_ascii_data (std::ostream& os, const octave_value& tc,
+		 const std::string& name, bool strip_nan_and_inf,
 		 bool mark_as_global, int precision) 
 {
   bool success = true;
@@ -2268,7 +2268,7 @@
 	{
 	  int len = chm.cols ();
 	  os << "# length: " << len << "\n";
-	  string tstr = chm.row_as_string (i);
+	  std::string tstr = chm.row_as_string (i);
 	  const char *tmp = tstr.data ();
 	  os.write (tmp, len);
 	  os << "\n";
@@ -2367,7 +2367,7 @@
 // Save the info from sr on stream os in the format specified by fmt.
 
 static void
-do_save (ostream& os, symbol_record *sr, load_save_format fmt,
+do_save (std::ostream& os, symbol_record *sr, load_save_format fmt,
 	 int save_as_floats)
 {
   if (! sr->is_variable ())
@@ -2376,8 +2376,8 @@
       return;
     }
 
-  string name = sr->name ();
-  string help = sr->help ();
+  std::string name = sr->name ();
+  std::string help = sr->help ();
   int global = sr->is_linked_to_global ();
 
   octave_value tc = sr->def ();
@@ -2410,7 +2410,7 @@
 // builtin variables with names that match PATTERN.
 
 static int
-save_vars (ostream& os, const string& pattern, bool save_builtins,
+save_vars (std::ostream& os, const std::string& pattern, bool save_builtins,
 	   load_save_format fmt, int save_as_floats)
 {
   Array<symbol_record *> vars = curr_sym_tab->glob
@@ -2452,7 +2452,7 @@
 {
   load_save_format retval = LS_ASCII;
 
-  string fmt = Vdefault_save_format;
+  std::string fmt = Vdefault_save_format;
 
   if (fmt == "binary")
     retval = LS_BINARY;
@@ -2463,7 +2463,7 @@
 }
 
 static void
-write_header (ostream& os, load_save_format format)
+write_header (std::ostream& os, load_save_format format)
 {
   switch (format)
     {
@@ -2484,7 +2484,7 @@
     case LS_ASCII:
       {
 	octave_gmtime now;
-	string time_string = now.asctime ();
+	std::string time_string = now.asctime ();
 	time_string = time_string.substr (0, time_string.length () - 1);
 
 	os << "# Created by Octave " OCTAVE_VERSION ", "
@@ -2504,7 +2504,7 @@
 
 static void
 save_vars (const string_vector& argv, int argv_idx, int argc,
-	   ostream& os, bool save_builtins, load_save_format fmt,
+	   std::ostream& os, bool save_builtins, load_save_format fmt,
 	   bool save_as_floats, bool write_header_info)
 {
   if (write_header_info)
@@ -2543,7 +2543,7 @@
       if (format == LS_BINARY || format == LS_MAT_BINARY)
 	mode |= ios::bin;
 
-      ofstream file (fname, mode);
+      std::ofstream file (fname, mode);
 
       if (file)
 	{
@@ -2702,7 +2702,7 @@
     }
   else
     {
-      string fname = file_ops::tilde_expand (argv[i]);
+      std::string fname = file_ops::tilde_expand (argv[i]);
 
       i++;
 
@@ -2712,7 +2712,7 @@
 
       mode |= append ? ios::ate : ios::trunc;
 
-      ofstream file (fname.c_str (), mode);
+      std::ofstream file (fname.c_str (), mode);
 
       if (file)
 	{
@@ -2739,7 +2739,7 @@
 // TRUE, assume a parametric 3-dimensional plot will be generated.
 
 bool
-save_three_d (ostream& os, const octave_value& tc, bool parametric)
+save_three_d (std::ostream& os, const octave_value& tc, bool parametric)
 {
   bool fail = false;
 
@@ -2806,7 +2806,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("default_save_format");
+  std::string s = builtin_string_variable ("default_save_format");
 
   if (s.empty ())
     {
diff --git a/src/load-save.h b/src/load-save.h
--- a/src/load-save.h
+++ b/src/load-save.h
@@ -29,13 +29,13 @@
 
 class octave_value;
 
-extern bool save_ascii_data (ostream& os, const octave_value& t,
-			     const string& name = string (),
+extern bool save_ascii_data (std::ostream& os, const octave_value& t,
+			     const std::string& name = std::string (),
 			     bool strip_nan_and_inf = false,
 			     bool mark_as_global = false,
 			     int precision = 0);
 
-extern bool save_three_d (ostream& os, const octave_value& t,
+extern bool save_three_d (std::ostream& os, const octave_value& t,
 			  bool parametric = false);
 
 extern void save_user_variables (void);
diff --git a/src/oct-fstrm.cc b/src/oct-fstrm.cc
--- a/src/oct-fstrm.cc
+++ b/src/oct-fstrm.cc
@@ -31,13 +31,13 @@
 #include "oct-fstrm.h"
 
 octave_stream
-octave_fstream::create (const string& nm_arg, ios::openmode md,
+octave_fstream::create (const std::string& nm_arg, ios::openmode md,
 			oct_mach_info::float_format flt_fmt)
 {
   return octave_stream (new octave_fstream (nm_arg, md, flt_fmt));
 }
 
-octave_fstream::octave_fstream (const string& nm_arg,
+octave_fstream::octave_fstream (const std::string& nm_arg,
 				ios::openmode md = ios::in|ios::out,
 				oct_mach_info::float_format flt_fmt)
   : octave_base_stream (md, flt_fmt), nm (nm_arg)
@@ -98,10 +98,10 @@
   return fs.eof ();
 }
 
-istream *
+std::istream *
 octave_fstream::input_stream (void)
 {
-  istream *retval = 0;
+  std::istream *retval = 0;
 
   if (mode () & ios::in)
     retval = &fs;
@@ -109,10 +109,10 @@
   return retval;
 }
 
-ostream *
+std::ostream *
 octave_fstream::output_stream (void)
 {
-  ostream *retval = 0;
+  std::ostream *retval = 0;
 
   if (mode () & ios::out)
     retval = &fs;
diff --git a/src/oct-fstrm.h b/src/oct-fstrm.h
--- a/src/oct-fstrm.h
+++ b/src/oct-fstrm.h
@@ -32,13 +32,13 @@
 {
 public:
 
-  octave_fstream (const string& nm_arg,
+  octave_fstream (const std::string& nm_arg,
 		  ios::openmode md = ios::in|ios::out,
 		  oct_mach_info::float_format flt_fmt =
 		  oct_mach_info::native);
 
   static octave_stream
-  create (const string& nm_arg, ios::openmode md = ios::in|ios::out,
+  create (const std::string& nm_arg, ios::openmode md = ios::in|ios::out,
 	  oct_mach_info::float_format flt_fmt = oct_mach_info::native);
 
   // Position a stream at OFFSET relative to ORIGIN.
@@ -55,11 +55,11 @@
 
   // The name of the file.
 
-  string name (void) const { return nm; }
+  std::string name (void) const { return nm; }
 
-  istream *input_stream (void);
+  std::istream *input_stream (void);
 
-  ostream *output_stream (void);
+  std::ostream *output_stream (void);
 
 protected:
 
@@ -67,7 +67,7 @@
 
 private:
 
-  string nm;
+  std::string nm;
 
   fstream fs;
 
diff --git a/src/oct-hist.cc b/src/oct-hist.cc
--- a/src/oct-hist.cc
+++ b/src/oct-hist.cc
@@ -76,7 +76,7 @@
 bool input_from_tmp_history_file = false;
 
 // Where history is saved.
-static string Vhistory_file;
+static std::string Vhistory_file;
 
 // The number of lines to keep in the history file.
 static int Vhistory_size;
@@ -92,7 +92,7 @@
 {
   int size = 1024;
 
-  string env_size = octave_env::getenv ("OCTAVE_HISTSIZE");
+  std::string env_size = octave_env::getenv ("OCTAVE_HISTSIZE");
 
   if (! env_size.empty ())
     {
@@ -108,9 +108,9 @@
 string
 default_history_file (void)
 {
-  string file;
+  std::string file;
 
-  string env_file = octave_env::getenv ("OCTAVE_HISTFILE");
+  std::string env_file = octave_env::getenv ("OCTAVE_HISTFILE");
 
   if (! env_file.empty ())
     {
@@ -125,7 +125,7 @@
 
   if (file.empty ())
     {
-      string home_dir = octave_env::get_home_directory ();
+      std::string home_dir = octave_env::get_home_directory ();
 
       if (! home_dir.empty ())
 	{
@@ -153,14 +153,14 @@
   int i;
   for (i = 1; i < argc; i++)
     {
-      string option = argv[i];
+      std::string option = argv[i];
 
       if (option == "-r" || option == "-w" || option == "-a"
 	  || option == "-n")
 	{
 	  if (i < argc - 1)
 	    {
-	      string file = file_ops::tilde_expand (argv[i+1]);
+	      std::string file = file_ops::tilde_expand (argv[i+1]);
 	      command_history::set_file (file);
 	    }
 
@@ -283,7 +283,7 @@
 // your heart's content.
 
 static void
-edit_history_repl_hist (const string& command)
+edit_history_repl_hist (const std::string& command)
 {
   if (! command.empty ())
     {
@@ -295,11 +295,11 @@
 	{
 	  int i = len - 1;
 
-	  string histent = command_history::get_entry (i);
+	  std::string histent = command_history::get_entry (i);
 
 	  if (! histent.empty ())
 	    {
-	      string cmd = command;
+	      std::string cmd = command;
 
 	      int cmd_len = cmd.length ();
 
@@ -314,11 +314,11 @@
 }
 
 static void
-edit_history_add_hist (const string& line)
+edit_history_add_hist (const std::string& line)
 {
   if (! line.empty ())
     {
-      string tmp = line;
+      std::string tmp = line;
 
       int len = tmp.length ();
 	
@@ -334,7 +334,7 @@
 mk_tmp_hist_file (int argc, const string_vector& argv,
 		  int insert_curr, const char *warn_for) 
 {
-  string retval;
+  std::string retval;
 
   string_vector hlist = command_history::list ();
 
@@ -403,7 +403,7 @@
       reverse = 1;
     }
 
-  string name = file_ops::tempnam ("", "oct-");
+  std::string name = file_ops::tempnam ("", "oct-");
 
   fstream file (name.c_str (), ios::out);
 
@@ -433,14 +433,14 @@
 static void
 do_edit_history (int argc, const string_vector& argv)
 {
-  string name = mk_tmp_hist_file (argc, argv, 0, "edit_history");
+  std::string name = mk_tmp_hist_file (argc, argv, 0, "edit_history");
 
   if (name.empty ())
     return;
 
   // Call up our favorite editor on the file of commands.
 
-  string cmd = Veditor;
+  std::string cmd = Veditor;
   cmd.append (" ");
   cmd.append (name);
 
@@ -506,7 +506,7 @@
 static void
 do_run_history (int argc, const string_vector& argv)
 {
-  string name = mk_tmp_hist_file (argc, argv, 1, "run_history");
+  std::string name = mk_tmp_hist_file (argc, argv, 1, "run_history");
 
   if (name.empty ())
     return;
@@ -671,7 +671,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("history_file");
+  std::string s = builtin_string_variable ("history_file");
 
   if (s.empty ())
     {
diff --git a/src/oct-hist.h b/src/oct-hist.h
--- a/src/oct-hist.h
+++ b/src/oct-hist.h
@@ -28,7 +28,7 @@
 #include "cmd-hist.h"
 
 extern int default_history_size (void);
-extern string default_history_file (void);
+extern std::string default_history_file (void);
 
 // TRUE means input is coming from temporary history file.
 extern bool input_from_tmp_history_file;
diff --git a/src/oct-iostrm.cc b/src/oct-iostrm.cc
--- a/src/oct-iostrm.cc
+++ b/src/oct-iostrm.cc
@@ -69,7 +69,7 @@
 }
 
 octave_stream
-octave_istream::create (istream *arg, const string& nm)
+octave_istream::create (std::istream *arg, const std::string& nm)
 {
   return octave_stream (new octave_istream (arg, nm));
 }
@@ -83,7 +83,7 @@
 }
 
 octave_stream
-octave_ostream::create (ostream *arg, const string& nm)
+octave_ostream::create (std::ostream *arg, const std::string& nm)
 {
   return octave_stream (new octave_ostream (arg, nm));
 }
diff --git a/src/oct-iostrm.h b/src/oct-iostrm.h
--- a/src/oct-iostrm.h
+++ b/src/oct-iostrm.h
@@ -32,7 +32,7 @@
 {
 public:
 
-  octave_base_iostream (const string& n = string (),
+  octave_base_iostream (const std::string& n = std::string (),
 			ios::openmode md = ios::in|ios::out,
 			oct_mach_info::float_format flt_fmt =
 			oct_mach_info::native)
@@ -52,7 +52,7 @@
 
   // The name of the file.
 
-  string name (void) const { return nm; }
+  std::string name (void) const { return nm; }
 
 protected:
 
@@ -62,7 +62,7 @@
 
 private:
 
-  string nm;
+  std::string nm;
 
   virtual const char *stream_type (void) const = 0;
 
@@ -78,20 +78,20 @@
 {
 public:
 
-  octave_istream (istream *arg = 0, const string& nm = string ())
+  octave_istream (std::istream *arg = 0, const std::string& nm = std::string ())
     : octave_base_iostream (nm, ios::in, oct_mach_info::native),
       is (arg) { }
 
   static octave_stream
-  create (istream *arg = 0, const string& nm = string ());
+  create (std::istream *arg = 0, const std::string& nm = std::string ());
 
   // Return non-zero if EOF has been reached on this stream.
 
   bool eof (void) const;
 
-  istream *input_stream (void) { return is; }
+  std::istream *input_stream (void) { return is; }
 
-  ostream *output_stream (void) { return 0; }
+  std::ostream *output_stream (void) { return 0; }
 
 protected:
 
@@ -99,7 +99,7 @@
 
 private:
 
-  istream *is;
+  std::istream *is;
 
   const char *stream_type (void) const { return "octave_istream"; }
 
@@ -115,20 +115,20 @@
 {
 public:
 
-  octave_ostream (ostream *arg, const string& nm = string ())
+  octave_ostream (std::ostream *arg, const std::string& nm = std::string ())
     : octave_base_iostream (nm, ios::out, oct_mach_info::native),
       os (arg) { }
 
   static octave_stream
-  create (ostream *arg, const string& nm = string ());
+  create (std::ostream *arg, const std::string& nm = std::string ());
 
   // Return non-zero if EOF has been reached on this stream.
 
   bool eof (void) const;
 
-  istream *input_stream (void) { return 0; }
+  std::istream *input_stream (void) { return 0; }
 
-  ostream *output_stream (void) { return os; }
+  std::ostream *output_stream (void) { return os; }
 
 protected:
 
@@ -136,7 +136,7 @@
 
 private:
 
-  ostream *os;
+  std::ostream *os;
 
   const char *stream_type (void) const { return "octave_ostream"; }
 
diff --git a/src/oct-lvalue.h b/src/oct-lvalue.h
--- a/src/oct-lvalue.h
+++ b/src/oct-lvalue.h
@@ -39,7 +39,7 @@
   octave_lvalue (octave_value *v = 0, symbol_record::change_function f = 0)
     : val (v), idx (), chg_fcn (f), struct_elt_name (), index_set (false) { }
 
-  octave_lvalue (octave_value *v, const string& nm,
+  octave_lvalue (octave_value *v, const std::string& nm,
 		 symbol_record::change_function f = 0)
     : val (v), idx (), chg_fcn (f), struct_elt_name (nm), index_set (false) { }
 
@@ -73,7 +73,7 @@
 
   void assign (octave_value::assign_op, const octave_value&);
 
-  octave_lvalue struct_elt_ref (const string& nm)
+  octave_lvalue struct_elt_ref (const std::string& nm)
     {
       val->make_unique ();
       return val->struct_elt_ref (nm);
@@ -104,7 +104,7 @@
 
   symbol_record::change_function chg_fcn;
 
-  string struct_elt_name;
+  std::string struct_elt_name;
 
   bool index_set;
 };
diff --git a/src/oct-map.h b/src/oct-map.h
--- a/src/oct-map.h
+++ b/src/oct-map.h
@@ -39,7 +39,7 @@
  public:
   Octave_map (void) : CHMap<octave_value> (octave_value ()) { }
 
-  Octave_map (const string& key, const octave_value& value)
+  Octave_map (const std::string& key, const octave_value& value)
     : CHMap<octave_value> (octave_value ())
       {
 	CHMap<octave_value>::operator [] (key) = value;
diff --git a/src/oct-obj.cc b/src/oct-obj.cc
--- a/src/oct-obj.cc
+++ b/src/oct-obj.cc
@@ -155,7 +155,7 @@
 }
 
 string_vector
-octave_value_list::make_argv (const string& fcn_name) const
+octave_value_list::make_argv (const std::string& fcn_name) const
 {
   string_vector argv;
 
@@ -167,7 +167,7 @@
 
       for (int i = 0; i < len; i++)
 	{
-	  // An empty string ("") has zero columns and zero rows (a
+	  // An empty std::string ("") has zero columns and zero rows (a
 	  // change that was made for Matlab contemptibility.
 
 	  int n = elem(i).rows ();
diff --git a/src/oct-obj.h b/src/oct-obj.h
--- a/src/oct-obj.h
+++ b/src/oct-obj.h
@@ -82,7 +82,7 @@
   octave_value_list (const char *s)
     : data (1, octave_value (s)) { }
 
-  octave_value_list (const string& s)
+  octave_value_list (const std::string& s)
     : data (1, octave_value (s)) { }
 
   octave_value_list (const string_vector& s)
@@ -140,7 +140,7 @@
 
   bool all_strings_p (void) const;
 
-  string_vector make_argv (const string&) const;
+  string_vector make_argv (const std::string&) const;
 
   void stash_name_tags (const string_vector& nm) { names = nm; }
 
diff --git a/src/oct-prcstrm.cc b/src/oct-prcstrm.cc
--- a/src/oct-prcstrm.cc
+++ b/src/oct-prcstrm.cc
@@ -29,13 +29,13 @@
 #include "oct-prcstrm.h"
 
 octave_stream
-octave_iprocstream::create (const string& n, ios::openmode arg_md,
+octave_iprocstream::create (const std::string& n, ios::openmode arg_md,
 			    oct_mach_info::float_format flt_fmt)
 {
   return octave_stream (new octave_iprocstream (n, arg_md, flt_fmt));
 }
 
-octave_iprocstream::octave_iprocstream (const string& n,
+octave_iprocstream::octave_iprocstream (const std::string& n,
 					ios::openmode arg_md,
 					oct_mach_info::float_format flt_fmt)
   : octave_istdiostream (n, 0, arg_md, flt_fmt)
@@ -45,7 +45,7 @@
   if (fp)
     {
       delete is;
-      is = new istdiostream (fp);
+      is = new std::istdiostream (fp);
     }
 }
 
@@ -59,13 +59,13 @@
 }
 
 octave_stream
-octave_oprocstream::create (const string& n, ios::openmode arg_md,
+octave_oprocstream::create (const std::string& n, ios::openmode arg_md,
 			    oct_mach_info::float_format flt_fmt)
 {
   return octave_stream (new octave_oprocstream (n, arg_md, flt_fmt));
 }
 
-octave_oprocstream::octave_oprocstream (const string& n,
+octave_oprocstream::octave_oprocstream (const std::string& n,
 					ios::openmode arg_md,
 					oct_mach_info::float_format flt_fmt)
   : octave_ostdiostream (n, 0, arg_md, flt_fmt)
@@ -75,7 +75,7 @@
   if (fp)
     {
       delete os;
-      os = new ostdiostream (fp);
+      os = new std::ostdiostream (fp);
     }
 }
 
diff --git a/src/oct-prcstrm.h b/src/oct-prcstrm.h
--- a/src/oct-prcstrm.h
+++ b/src/oct-prcstrm.h
@@ -30,13 +30,13 @@
 {
 public:
 
-  octave_iprocstream (const string& n,
+  octave_iprocstream (const std::string& n,
 		      ios::openmode arg_md = ios::in,
 		      oct_mach_info::float_format flt_fmt =
 		      oct_mach_info::native);
 
   static octave_stream
-  create (const string& n, ios::openmode arg_md = ios::in,
+  create (const std::string& n, ios::openmode arg_md = ios::in,
 	  oct_mach_info::float_format flt_fmt = oct_mach_info::native);
 
 protected:
@@ -57,13 +57,13 @@
 {
 public:
 
-  octave_oprocstream (const string& n,
+  octave_oprocstream (const std::string& n,
 		      ios::openmode arg_md = ios::out,
 		      oct_mach_info::float_format flt_fmt =
 		      oct_mach_info::native);
 
   static octave_stream
-  create (const string& n, ios::openmode arg_md = ios::out,
+  create (const std::string& n, ios::openmode arg_md = ios::out,
 	  oct_mach_info::float_format flt_fmt = oct_mach_info::native);
 
 protected:
diff --git a/src/oct-stdstrm.cc b/src/oct-stdstrm.cc
--- a/src/oct-stdstrm.cc
+++ b/src/oct-stdstrm.cc
@@ -84,20 +84,20 @@
 }
 
 octave_stream
-octave_istdiostream::create (const string& n, FILE *f,
+octave_istdiostream::create (const std::string& n, FILE *f,
 			     ios::openmode arg_md,
 			     oct_mach_info::float_format flt_fmt)
 {
   return octave_stream (new octave_istdiostream (n, f, arg_md, flt_fmt));
 }
 
-octave_istdiostream::octave_istdiostream (const string& n, FILE *f,
+octave_istdiostream::octave_istdiostream (const std::string& n, FILE *f,
 					  ios::openmode arg_md,
 					  oct_mach_info::float_format flt_fmt)
   : octave_base_stdiostream (n, f, arg_md, flt_fmt), is (0)
 {
   if (f)
-    is = new istdiostream (f);
+    is = new std::istdiostream (f);
 }
 
 octave_istdiostream::~octave_istdiostream (void)
@@ -106,20 +106,20 @@
 }
 
 octave_stream
-octave_ostdiostream::create (const string& n, FILE *f,
+octave_ostdiostream::create (const std::string& n, FILE *f,
 			     ios::openmode arg_md,
 			     oct_mach_info::float_format flt_fmt)
 {
   return octave_stream (new octave_ostdiostream (n, f, arg_md, flt_fmt));
 }
 
-octave_ostdiostream::octave_ostdiostream (const string& n, FILE *f,
+octave_ostdiostream::octave_ostdiostream (const std::string& n, FILE *f,
 					  ios::openmode arg_md,
 					  oct_mach_info::float_format flt_fmt)
   : octave_base_stdiostream (n, f, arg_md, flt_fmt), os (0)
 {
   if (f)
-    os = new ostdiostream (f);
+    os = new std::ostdiostream (f);
 }
 
 octave_ostdiostream::~octave_ostdiostream (void)
diff --git a/src/oct-stdstrm.h b/src/oct-stdstrm.h
--- a/src/oct-stdstrm.h
+++ b/src/oct-stdstrm.h
@@ -32,7 +32,7 @@
 {
 public:
 
-  octave_base_stdiostream (const string& n, FILE *f,
+  octave_base_stdiostream (const std::string& n, FILE *f,
 			   ios::openmode arg_md = ios::in|ios::out,
 			   oct_mach_info::float_format flt_fmt =
 			   oct_mach_info::native)
@@ -48,7 +48,7 @@
 
   // The name of the file.
 
-  string name (void) const { return nm; }
+  std::string name (void) const { return nm; }
 
   virtual stdiobuf *rdbuf (void) const = 0;
 
@@ -58,7 +58,7 @@
 
 protected:
 
-  string nm;
+  std::string nm;
 
   FILE *fp;
 
@@ -76,26 +76,26 @@
 {
 public:
 
-  octave_istdiostream (const string& n, FILE *f = 0,
+  octave_istdiostream (const std::string& n, FILE *f = 0,
 		       ios::openmode arg_md = ios::in,
 		       oct_mach_info::float_format flt_fmt =
 		       oct_mach_info::native);
 
   static octave_stream
-  create (const string& n, FILE *f = 0, ios::openmode arg_md = ios::in,
+  create (const std::string& n, FILE *f = 0, ios::openmode arg_md = ios::in,
 	  oct_mach_info::float_format flt_fmt = oct_mach_info::native);
 
   // Return non-zero if EOF has been reached on this stream.
 
   bool eof (void) const { return is ? is->eof () : true; }
 
-  istream *input_stream (void) { return is; }
+  std::istream *input_stream (void) { return is; }
 
-  ostream *output_stream (void) { return 0; }
+  std::ostream *output_stream (void) { return 0; }
 
   // XXX FIXME XXX -- should not have to cast away const here.
   stdiobuf *rdbuf (void) const
-    { return is ? (const_cast<istdiostream *> (is))->rdbuf () : 0; }
+    { return is ? (const_cast<std::istdiostream *> (is))->rdbuf () : 0; }
 
   bool bad (void) const { return is ? is->bad () : true; }
 
@@ -107,7 +107,7 @@
 
 protected:
 
-  istdiostream *is;
+  std::istdiostream *is;
 
   ~octave_istdiostream (void);
 
@@ -125,26 +125,26 @@
 {
 public:
 
-  octave_ostdiostream (const string& n, FILE *f = 0,
+  octave_ostdiostream (const std::string& n, FILE *f = 0,
 		       ios::openmode arg_md = ios::out,
 		       oct_mach_info::float_format flt_fmt =
 		       oct_mach_info::native);
 
   static octave_stream
-  create (const string& n, FILE *f = 0, ios::openmode arg_md = ios::out,
+  create (const std::string& n, FILE *f = 0, ios::openmode arg_md = ios::out,
 	  oct_mach_info::float_format flt_fmt = oct_mach_info::native);
 
   // Return non-zero if EOF has been reached on this stream.
 
   bool eof (void) const { return os ? os->eof () : true; }
 
-  istream *input_stream (void) { return 0; }
+  std::istream *input_stream (void) { return 0; }
 
-  ostream *output_stream (void) { return os; }
+  std::ostream *output_stream (void) { return os; }
 
   // XXX FIXME XXX -- should not have to cast away const here.
   stdiobuf *rdbuf (void) const
-    { return os ? (const_cast<ostdiostream *> (os))->rdbuf () : 0; }
+    { return os ? (const_cast<std::ostdiostream *> (os))->rdbuf () : 0; }
 
   bool bad (void) const { return os ? os->bad () : true; }
 
@@ -156,7 +156,7 @@
 
 protected:
 
-  ostdiostream *os;
+  std::ostdiostream *os;
 
   ~octave_ostdiostream (void);
 
diff --git a/src/oct-stream.cc b/src/oct-stream.cc
--- a/src/oct-stream.cc
+++ b/src/oct-stream.cc
@@ -152,7 +152,7 @@
     }
 }
 
-scanf_format_list::scanf_format_list (const string& s)
+scanf_format_list::scanf_format_list (const std::string& s)
   : nconv (0), curr_idx (0), list (16), buf (0)
 {
   int num_elts = 0;
@@ -173,7 +173,7 @@
       have_more = true;
 
       if (! buf)
-	buf = new ostrstream ();
+	buf = new std::ostrstream ();
 
       if (s[i] == '%')
 	{
@@ -244,7 +244,7 @@
 void
 scanf_format_list::add_elt_to_list (int width, bool discard, char type,
 				    char modifier, int& num_elts,
-				    const string& char_class)
+				    const std::string& char_class)
 {
   if (buf)
     {
@@ -275,9 +275,9 @@
 }
 
 static string
-expand_char_class (const string& s)
+expand_char_class (const std::string& s)
 {
-  string retval;
+  std::string retval;
 
   size_t len = s.length ();
 
@@ -310,7 +310,7 @@
 }
 
 void
-scanf_format_list::process_conversion (const string& s, int& i, int n,
+scanf_format_list::process_conversion (const std::string& s, int& i, int n,
 				       int& width, bool& discard, char& type,
 				       char& modifier, int& num_elts)
 {
@@ -412,13 +412,13 @@
 }
 
 int
-scanf_format_list::finish_conversion (const string& s, int& i, int n,
+scanf_format_list::finish_conversion (const std::string& s, int& i, int n,
 				      int& width, bool discard, char& type,
 				      char modifier, int& num_elts)
 {
   int retval = 0;
 
-  string char_class;
+  std::string char_class;
 
   if (s[i] == '%')
     *buf << s[i++];
@@ -572,7 +572,7 @@
 
 // Ugh again.
 
-printf_format_list::printf_format_list (const string& s)
+printf_format_list::printf_format_list (const std::string& s)
   : nconv (0), curr_idx (0), list (16), buf (0)
 {
   int num_elts = 0;
@@ -592,7 +592,7 @@
       have_more = true;
 
       if (! buf)
-	buf = new ostrstream ();
+	buf = new std::ostrstream ();
 
       switch (s[i])
 	{
@@ -667,7 +667,7 @@
 }
 
 void
-printf_format_list::process_conversion (const string& s, int& i, int n,
+printf_format_list::process_conversion (const std::string& s, int& i, int n,
 					int& args, char& modifier,
 					char& type, int& num_elts)
 {
@@ -750,7 +750,7 @@
 }
 
 void
-printf_format_list::finish_conversion (const string& s, int& i,
+printf_format_list::finish_conversion (const std::string& s, int& i,
 				       int args, char modifier,
 				       char& type, int& num_elts)
 
@@ -839,8 +839,8 @@
 
   int retval = -1;
 
-  istream *is = input_stream ();
-  ostream *os = output_stream ();
+  std::istream *is = input_stream ();
+  std::ostream *os = output_stream ();
 
   int i_fid = is ? ((filebuf *) (is->rdbuf ()))->fd () : -1;
   int o_fid = os ? ((filebuf *) (os->rdbuf ()))->fd () : -1;
@@ -859,7 +859,7 @@
 }
 
 void
-octave_base_stream::error (const string& msg)
+octave_base_stream::error (const std::string& msg)
 {
   fail = true;
   errmsg = msg;
@@ -879,19 +879,19 @@
 octave_base_stream::do_gets (int max_len, bool& err,
 			     bool strip_newline, const char *fcn)
 {
-  string retval;
+  std::string retval;
 
   err = false;
 
-  istream *isp = input_stream ();
+  std::istream *isp = input_stream ();
 
   if (isp)
     {
-      istream& is = *isp;
+      std::istream& is = *isp;
 
       // XXX FIXME XXX -- this should probably be converted to use
       // sstream when that is available.
-      ostrstream buf;
+      std::ostrstream buf;
 
       int c = 0;
       int count = 0;
@@ -920,14 +920,14 @@
       if (is.fail ())
 	{
 	  err = true;
-	  string msg = fcn;
+	  std::string msg = fcn;
 	  msg.append (": read error");
 	  error (msg);
 	}
       else if (count == 0 && is.eof ())
 	{
 	  err = true;
-	  string msg = fcn;
+	  std::string msg = fcn;
 	  msg.append (": at end of file");
 	  error (msg);
 	}
@@ -969,11 +969,11 @@
 
   count = 0;
 
-  istream *isp = input_stream ();
+  std::istream *isp = input_stream ();
 
   if (isp)
     {
-      istream& is = *isp;
+      std::istream& is = *isp;
 
       int nr = -1;
       int nc = -1;
@@ -1003,7 +1003,7 @@
 
 template <class T>
 void
-do_scanf_conv (istream& is, const char *fmt, T valptr, Matrix& mval,
+do_scanf_conv (std::istream& is, const char *fmt, T valptr, Matrix& mval,
 	       double *data, int& idx, int& conv_count, int nr,
 	       int max_size, bool discard) 
 {
@@ -1032,25 +1032,25 @@
 }
 
 template void
-do_scanf_conv (istream&, const char*, int*, Matrix&, double*, int&,
+do_scanf_conv (std::istream&, const char*, int*, Matrix&, double*, int&,
 	       int&, int, int, bool);
 
 template void
-do_scanf_conv (istream&, const char*, long int*, Matrix&, double*, int&,
+do_scanf_conv (std::istream&, const char*, long int*, Matrix&, double*, int&,
 	       int&, int, int, bool);
 
 template void
-do_scanf_conv (istream&, const char*, short int*, Matrix&, double*, int&,
+do_scanf_conv (std::istream&, const char*, short int*, Matrix&, double*, int&,
 	       int&, int, int, bool);
 
 #if 0
 template void
-do_scanf_conv (istream&, const char*, float*, Matrix&, double*, int&,
+do_scanf_conv (std::istream&, const char*, float*, Matrix&, double*, int&,
 	       int&, int, int, bool);
 #endif
 
 template void
-do_scanf_conv (istream&, const char*, double*, Matrix&, double*, int&,
+do_scanf_conv (std::istream&, const char*, double*, Matrix&, double*, int&,
 	       int&, int, int, bool);
 
 #define DO_WHITESPACE_CONVERSION() \
@@ -1170,7 +1170,7 @@
 	{ \
 	  ostrstream buf; \
  \
-	  string char_class = elt->char_class; \
+	  std::string char_class = elt->char_class; \
  \
 	  int c = EOF; \
  \
@@ -1260,7 +1260,7 @@
       return Matrix (nr, nc, 0.0);
     }
 
-  istream *isp = input_stream ();
+  std::istream *isp = input_stream ();
 
   bool all_char_conv = fmt_list.all_character_conversions ();
 
@@ -1316,7 +1316,7 @@
 
   if (isp)
     {
-      istream& is = *isp;
+      std::istream& is = *isp;
 
       const scanf_format_elt *elt = fmt_list.first ();
 
@@ -1554,11 +1554,11 @@
 
   count = 0;
 
-  istream *isp = input_stream ();
+  std::istream *isp = input_stream ();
 
   if (isp)
     {
-      istream& is = *isp;
+      std::istream& is = *isp;
 
       scanf_format_list fmt_list (fmt);
 
@@ -1631,11 +1631,11 @@
 {
   bool quit = false;
 
-  istream *isp = input_stream ();
+  std::istream *isp = input_stream ();
 
   if (isp)
     {
-      istream& is = *isp;
+      std::istream& is = *isp;
 
       ios::fmtflags flags = is.flags ();
 
@@ -1766,15 +1766,15 @@
 }
 
 octave_value_list
-octave_base_stream::oscanf (const string& fmt)
+octave_base_stream::oscanf (const std::string& fmt)
 {
   octave_value_list retval;
 
-  istream *isp = input_stream ();
+  std::istream *isp = input_stream ();
 
   if (isp)
     {
-      istream& is = *isp;
+      std::istream& is = *isp;
 
       scanf_format_list fmt_list (fmt);
 
@@ -1878,7 +1878,7 @@
 {
   int retval = -1;
 
-  ostream *os = output_stream ();
+  std::ostream *os = output_stream ();
 
   if (os)
     {
@@ -1900,11 +1900,11 @@
 {
   int retval = -1;
 
-  ostream *osp = output_stream ();
+  std::ostream *osp = output_stream ();
 
   if (osp)
     {
-      ostream& os = *osp;
+      std::ostream& os = *osp;
 
       Matrix mval = data.matrix_value ();
 
@@ -1948,7 +1948,7 @@
   int int_value (void);
 
   // Get the current value as a string and advance the internal pointer.
-  string string_value (void);
+  std::string string_value (void);
 
   operator bool () const { return (curr_state == ok); }
 
@@ -2072,7 +2072,7 @@
 string
 printf_value_cache::string_value (void)
 {
-  string retval;
+  std::string retval;
 
   if (looking_at_string ())
     {
@@ -2095,7 +2095,7 @@
 
 template <class T>
 void
-do_printf_conv (ostream& os, const char *fmt, int nsa, int sa_1,
+do_printf_conv (std::ostream& os, const char *fmt, int nsa, int sa_1,
 		int sa_2, bool have_arg, T arg)
 {
   switch (nsa)
@@ -2128,16 +2128,16 @@
 }
 
 template void
-do_printf_conv (ostream&, const char*, int, int, int, bool, int);
+do_printf_conv (std::ostream&, const char*, int, int, int, bool, int);
 
 template void
-do_printf_conv (ostream&, const char*, int, int, int, bool, long);
+do_printf_conv (std::ostream&, const char*, int, int, int, bool, long);
 
 template void
-do_printf_conv (ostream&, const char*, int, int, int, bool, double);
+do_printf_conv (std::ostream&, const char*, int, int, int, bool, double);
 
 template void
-do_printf_conv (ostream&, const char*, int, int, int, bool, const char*);
+do_printf_conv (std::ostream&, const char*, int, int, int, bool, const char*);
 
 int
 octave_base_stream::do_printf (printf_format_list& fmt_list,
@@ -2145,11 +2145,11 @@
 {
   int retval = -1;
 
-  ostream *osp = output_stream ();
+  std::ostream *osp = output_stream ();
 
   if (osp)
     {
-      ostream& os = *osp;
+      std::ostream& os = *osp;
 
       const printf_format_elt *elt = fmt_list.first ();
 
@@ -2196,7 +2196,7 @@
 		{
 		  if (elt->type == 's' && val_cache.looking_at_string ())
 		    {
-		      string val = val_cache.string_value ();
+		      std::string val = val_cache.string_value ();
 
 		      if (val_cache)
 			do_printf_conv (os, fmt, nsa, sa_1, sa_2, true,
@@ -2273,15 +2273,15 @@
 }
 
 int
-octave_base_stream::printf (const string& fmt, const octave_value_list& args)
+octave_base_stream::printf (const std::string& fmt, const octave_value_list& args)
 {
   int retval = -1;
 
-  ostream *osp = output_stream ();
+  std::ostream *osp = output_stream ();
 
   if (osp)
     {
-      ostream& os = *osp;
+      std::ostream& os = *osp;
 
       printf_format_list fmt_list (fmt);
 
@@ -2324,15 +2324,15 @@
 }
 
 int
-octave_base_stream::puts (const string& s)
+octave_base_stream::puts (const std::string& s)
 {
   int retval = -1;
 
-  ostream *osp = output_stream ();
+  std::ostream *osp = output_stream ();
 
   if (osp)
     {
-      ostream& os = *osp;
+      std::ostream& os = *osp;
 
       os << s;
 
@@ -2374,7 +2374,7 @@
 {
   err_num = fail ? -1 : 0;
 
-  string tmp = errmsg;
+  std::string tmp = errmsg;
 
   if (clear_err)
     clear ();
@@ -2385,7 +2385,7 @@
 void
 octave_base_stream::invalid_operation (const char *op, const char *rw)
 {
-  string msg = op;
+  std::string msg = op;
   msg.append (": stream not open for ");
   msg.append (rw);
   error (msg);
@@ -2442,7 +2442,7 @@
 string
 octave_stream::getl (int max_len, bool& err)
 {
-  string retval;
+  std::string retval;
 
   if (stream_ok ("getl"))
     retval = rep->getl (max_len, err);
@@ -2453,7 +2453,7 @@
 string
 octave_stream::getl (const octave_value& tc_max_len, bool& err)
 {
-  string retval;
+  std::string retval;
 
   err = false;
 
@@ -2475,7 +2475,7 @@
 string
 octave_stream::gets (int max_len, bool& err)
 {
-  string retval;
+  std::string retval;
 
   if (stream_ok ("fgets"))
     retval = rep->gets (max_len, err);
@@ -2486,7 +2486,7 @@
 string
 octave_stream::gets (const octave_value& tc_max_len, bool& err)
 {
-  string retval;
+  std::string retval;
 
   err = false;
 
@@ -2532,7 +2532,7 @@
 
       if (tc_origin.is_string ())
 	{
-	  string xorigin = tc_origin.string_value ();
+	  std::string xorigin = tc_origin.string_value ();
 
 	  if (xorigin == "bof")
 	    origin = ios::beg;
@@ -2638,7 +2638,7 @@
 }
 
 octave_value
-octave_stream::scanf (const string& fmt, const Matrix& size, int& count)
+octave_stream::scanf (const std::string& fmt, const Matrix& size, int& count)
 {
   octave_value retval;
 
@@ -2649,7 +2649,7 @@
 }
 
 octave_value_list
-octave_stream::oscanf (const string& fmt)
+octave_stream::oscanf (const std::string& fmt)
 {
   octave_value_list retval;
 
@@ -2660,7 +2660,7 @@
 }
 
 int
-octave_stream::printf (const string& fmt, const octave_value_list& args)
+octave_stream::printf (const std::string& fmt, const octave_value_list& args)
 {
   int retval = -1;
 
@@ -2671,7 +2671,7 @@
 }
 
 int
-octave_stream::puts (const string& s)
+octave_stream::puts (const std::string& s)
 {
   int retval = -1;
 
@@ -2690,7 +2690,7 @@
 
   if (tc_s.is_string ())
     {
-      string s = tc_s.string_value ();      
+      std::string s = tc_s.string_value ();      
       retval = rep->puts (s);
     }
   else
@@ -2713,7 +2713,7 @@
 string
 octave_stream::error (bool clear, int& err_num)
 {
-  string retval;
+  std::string retval;
 
   if (stream_ok ("ferror", false))
     retval = rep->error (clear, err_num);
@@ -2724,7 +2724,7 @@
 string
 octave_stream::name (void) const
 {
-  string retval;
+  std::string retval;
 
   if (stream_ok ("name"))
     retval = rep->name ();
@@ -2757,7 +2757,7 @@
 string
 octave_stream::mode_as_string (int mode)
 {
-  string retval = "???";
+  std::string retval = "???";
 
   switch (mode)
     {
@@ -2851,25 +2851,25 @@
 }
 
 octave_stream
-octave_stream_list::lookup (int fid, const string& who)
+octave_stream_list::lookup (int fid, const std::string& who)
 {
   return (instance_ok ()) ? instance->do_lookup (fid, who) : octave_stream ();
 }
 
 octave_stream
-octave_stream_list::lookup (const octave_value& fid, const string& who)
+octave_stream_list::lookup (const octave_value& fid, const std::string& who)
 {
   return (instance_ok ()) ? instance->do_lookup (fid, who) : octave_stream ();
 }
 
 int
-octave_stream_list::remove (int fid, const string& who)
+octave_stream_list::remove (int fid, const std::string& who)
 {
   return (instance_ok ()) ? instance->do_remove (fid, who) : -1;
 }
 
 int
-octave_stream_list::remove (const octave_value& fid, const string& who)
+octave_stream_list::remove (const octave_value& fid, const std::string& who)
 {
   return (instance_ok ()) ? instance->do_remove (fid, who) : -1;
 }
@@ -2896,7 +2896,7 @@
 string
 octave_stream_list::list_open_files (void)
 {
-  return (instance_ok ()) ? instance->do_list_open_files () : string ();
+  return (instance_ok ()) ? instance->do_list_open_files () : std::string ();
 }
 
 octave_value
@@ -2950,7 +2950,7 @@
 }
 
 static void
-gripe_invalid_file_id (int fid, const string& who)
+gripe_invalid_file_id (int fid, const std::string& who)
 {
   if (who.empty ())
     ::error ("invalid stream number = %d", fid);
@@ -2959,7 +2959,7 @@
 }
 
 octave_stream
-octave_stream_list::do_lookup (int fid, const string& who) const
+octave_stream_list::do_lookup (int fid, const std::string& who) const
 {
   octave_stream retval;
 
@@ -2973,7 +2973,7 @@
 
 octave_stream
 octave_stream_list::do_lookup (const octave_value& fid,
-			       const string& who) const
+			       const std::string& who) const
 {
   octave_stream retval;
 
@@ -2986,7 +2986,7 @@
 }
 
 int
-octave_stream_list::do_remove (int fid, const string& who)
+octave_stream_list::do_remove (int fid, const std::string& who)
 {
   int retval = -1;
 
@@ -3012,7 +3012,7 @@
 }
 
 int
-octave_stream_list::do_remove (const octave_value& fid, const string& who)
+octave_stream_list::do_remove (const octave_value& fid, const std::string& who)
 {
   int retval = -1;
 
@@ -3079,11 +3079,11 @@
 string
 octave_stream_list::do_list_open_files (void) const
 {
-  string retval;
+  std::string retval;
 
   // XXX FIXME XXX -- this should probably be converted to use sstream
   // when that is available.
-  ostrstream buf;
+  std::ostrstream buf;
 
   buf << "\n"
       << "  number  mode  arch       name\n"
@@ -3095,12 +3095,12 @@
 
       if (os)
 	{
-	  string mode = octave_stream::mode_as_string (os.mode ());
-
-	  string arch =
+	  std::string mode = octave_stream::mode_as_string (os.mode ());
+
+	  std::string arch =
 	    oct_mach_info::float_format_as_string (os.float_format ());
 
-	  string name = os.name ();
+	  std::string name = os.name ();
 
 	  buf << "  "
 	      << setiosflags (ios::right)
@@ -3150,7 +3150,7 @@
 
   if (fid.is_string ())
     {
-      string nm = fid.string_value ();
+      std::string nm = fid.string_value ();
 
       // stdin (cin), stdout (cout), and stderr (cerr) are unnamed.
 
@@ -3172,7 +3172,7 @@
       int int_fid = convert_to_valid_int (fid, conv_err);
 
       if (conv_err)
-	::error ("file id must be a file object, string, or integer value");
+	::error ("file id must be a file object, std::string, or integer value");
       else
 	retval = int_fid;
     }
diff --git a/src/oct-stream.h b/src/oct-stream.h
--- a/src/oct-stream.h
+++ b/src/oct-stream.h
@@ -47,7 +47,7 @@
 
   scanf_format_elt (const char *txt = 0, int w = 0, bool d = false,
 		    char typ = '\0', char mod = '\0',
-		    const string& ch_class = string ())
+		    const std::string& ch_class = std::string ())
     : text (txt), width (w), discard (d), type (typ), modifier (mod),
       char_class (ch_class) { }
 
@@ -58,7 +58,7 @@
   bool discard;
   char type;
   char modifier;
-  string char_class;
+  std::string char_class;
 };
 
 class
@@ -66,7 +66,7 @@
 {
 public:
 
-  scanf_format_list (const string& fmt = string ());
+  scanf_format_list (const std::string& fmt = std::string ());
 
   ~scanf_format_list (void);
 
@@ -108,7 +108,7 @@
 
 private:
 
-  // Number of conversions specified by this format string, or -1 if
+  // Number of conversions specified by this format std::string, or -1 if
   // invalid conversions have been found.
   int nconv;
 
@@ -119,16 +119,16 @@
   Array<scanf_format_elt*> list;
 
   // Temporary buffer.
-  ostrstream *buf;
+  std::ostrstream *buf;
 
   void add_elt_to_list (int width, bool discard, char type, char modifier,
-			int& num_elts, const string& char_class = string ());
+			int& num_elts, const std::string& char_class = std::string ());
 
-  void process_conversion (const string& s, int& i, int n, int& width,
+  void process_conversion (const std::string& s, int& i, int n, int& width,
 			   bool& discard, char& type, char& modifier,
 			   int& num_elts);
 
-  int finish_conversion (const string& s, int& i, int n, int& width,
+  int finish_conversion (const std::string& s, int& i, int n, int& width,
 			 bool discard, char& type, char modifier,
 			 int& num_elts);
   // No copying!
@@ -158,7 +158,7 @@
 {
 public:
 
-  printf_format_list (const string& fmt = string ());
+  printf_format_list (const std::string& fmt = std::string ());
 
   ~printf_format_list (void);
 
@@ -189,7 +189,7 @@
 
 private:
 
-  // Number of conversions specified by this format string, or -1 if
+  // Number of conversions specified by this format std::string, or -1 if
   // invalid conversions have been found.
   int nconv;
 
@@ -200,15 +200,15 @@
   Array<printf_format_elt*> list;
 
   // Temporary buffer.
-  ostrstream *buf;
+  std::ostrstream *buf;
 
   void add_elt_to_list (int args, char type, char modifier,
 			int& num_elts);
 
-  void process_conversion (const string& s, int& i, int n, int& args,
+  void process_conversion (const std::string& s, int& i, int n, int& args,
 			   char& modifier, char& type, int& num_elts);
 
-  void finish_conversion (const string& s, int& i, int args,
+  void finish_conversion (const std::string& s, int& i, int args,
 			  char modifier, char& type, int& num_elts);
 
   // No copying!
@@ -251,19 +251,19 @@
 
   // The name of the file.
 
-  virtual string name (void) const = 0;
+  virtual std::string name (void) const = 0;
 
   // If the derived class provides this function and it returns a
   // pointer to a valid istream, scanf(), read(), getl(), and gets()
   // will automatically work for this stream.
 
-  virtual istream *input_stream (void) { return 0; }
+  virtual std::istream *input_stream (void) { return 0; }
 
   // If the derived class provides this function and it returns a
   // pointer to a valid ostream, flush(), write(), and printf() will
   // automatically work for this stream.
 
-  virtual ostream *output_stream (void) { return 0; }
+  virtual std::ostream *output_stream (void) { return 0; }
 
   // Return TRUE if this stream is open.
 
@@ -277,7 +277,7 @@
 
   // Return current error message for this stream.
 
-  string error (bool clear, int& err_num);
+  std::string error (bool clear, int& err_num);
 
 protected:
 
@@ -287,7 +287,7 @@
 
   // Set current error state and set fail to TRUE.
 
-  void error (const string& msg);
+  void error (const std::string& msg);
 
   // Clear any error message and set fail to FALSE.
 
@@ -312,16 +312,16 @@
   bool open_state;
 
   // Should contain error message if fail is TRUE.
-  string errmsg;
+  std::string errmsg;
 
   // Functions that are defined for all input streams (input streams
   // are those that define is).
 
-  string do_gets (int max_len, bool& err, bool strip_newline,
+  std::string do_gets (int max_len, bool& err, bool strip_newline,
 		  const char *fcn);
 
-  string getl (int max_len, bool& err);
-  string gets (int max_len, bool& err);
+  std::string getl (int max_len, bool& err);
+  std::string gets (int max_len, bool& err);
 
   octave_value do_read (int nr, int nc, oct_data_conv::data_type dt,
 			int skip, oct_mach_info::float_format flt_fmt,
@@ -340,11 +340,11 @@
   octave_value do_scanf (scanf_format_list& fmt_list, int nr, int nc,
 			 bool one_elt_size_spec, int& count);
 
-  octave_value scanf (const string& fmt, const Matrix& size, int& count);
+  octave_value scanf (const std::string& fmt, const Matrix& size, int& count);
 
   bool do_oscanf (const scanf_format_elt *elt, octave_value&);
 
-  octave_value_list oscanf (const string& fmt);
+  octave_value_list oscanf (const std::string& fmt);
 
   // Functions that are defined for all output streams (output streams
   // are those that define os).
@@ -359,9 +359,9 @@
 
   int do_printf (printf_format_list& fmt_list, const octave_value_list& args);
 
-  int printf (const string& fmt, const octave_value_list& args);
+  int printf (const std::string& fmt, const octave_value_list& args);
 
-  int puts (const string& s);
+  int puts (const std::string& s);
 
   // We can always do this in terms of seek(), so the derived class
   // only has to provide that.
@@ -392,11 +392,11 @@
 
   int flush (void);
 
-  string getl (int max_len, bool& err);
-  string getl (const octave_value& max_len, bool& err);
+  std::string getl (int max_len, bool& err);
+  std::string getl (const octave_value& max_len, bool& err);
 
-  string gets (int max_len, bool& err);
-  string gets (const octave_value& max_len, bool& err);
+  std::string gets (int max_len, bool& err);
+  std::string gets (const octave_value& max_len, bool& err);
 
   int seek (streamoff offset, ios::seek_dir origin);
   int seek (const octave_value& offset, const octave_value& origin);
@@ -416,20 +416,20 @@
   int write (const octave_value& data, oct_data_conv::data_type dt,
 	     int skip, oct_mach_info::float_format flt_fmt);
 
-  octave_value scanf (const string& fmt, const Matrix& size, int& count);
+  octave_value scanf (const std::string& fmt, const Matrix& size, int& count);
 
-  octave_value_list oscanf (const string& fmt);
+  octave_value_list oscanf (const std::string& fmt);
 
-  int printf (const string& fmt, const octave_value_list& args);
+  int printf (const std::string& fmt, const octave_value_list& args);
 
-  int puts (const string& s);
+  int puts (const std::string& s);
   int puts (const octave_value& s);
 
   bool eof (void) const;
 
-  string error (bool clear, int& err_num);
+  std::string error (bool clear, int& err_num);
 
-  string error (bool clear = false)
+  std::string error (bool clear = false)
     {
       int err_num;
       return error (clear, err_num);
@@ -443,17 +443,17 @@
 
   operator bool () const { return ok (); }
 
-  string name (void) const;
+  std::string name (void) const;
 
   int mode (void) const;
 
   oct_mach_info::float_format float_format (void) const;
 
-  static string mode_as_string (int mode);
+  static std::string mode_as_string (int mode);
 
-  istream *input_stream (void) { return rep ? rep->input_stream () : 0; }
+  std::istream *input_stream (void) { return rep ? rep->input_stream () : 0; }
 
-  ostream *output_stream (void) { return rep ? rep->output_stream () : 0; }
+  std::ostream *output_stream (void) { return rep ? rep->output_stream () : 0; }
 
 private:
 
@@ -480,7 +480,7 @@
       return retval;
     }
 
-  void error (const string& msg)
+  void error (const std::string& msg)
     {
       if (rep)
 	rep->error (msg);
@@ -502,20 +502,20 @@
 
   static octave_value insert (const octave_stream& os);
 
-  static octave_stream lookup (int fid, const string& who = string ());
+  static octave_stream lookup (int fid, const std::string& who = std::string ());
   static octave_stream lookup (const octave_value& fid,
-			       const string& who = string ());
+			       const std::string& who = std::string ());
 
-  static int remove (int fid, const string& who = string ());
+  static int remove (int fid, const std::string& who = std::string ());
   static int remove (const octave_value& fid,
-		     const string& who = string ());
+		     const std::string& who = std::string ());
 
   static void clear (void);
 
   static string_vector get_info (int fid);
   static string_vector get_info (const octave_value& fid);
 
-  static string list_open_files (void);
+  static std::string list_open_files (void);
 
   static octave_value open_file_numbers (void);
 
@@ -531,19 +531,19 @@
 
   octave_value do_insert (const octave_stream& os);
 
-  octave_stream do_lookup (int fid, const string& who = string ()) const;
+  octave_stream do_lookup (int fid, const std::string& who = std::string ()) const;
   octave_stream do_lookup (const octave_value& fid,
-			   const string& who = string ()) const;
+			   const std::string& who = std::string ()) const;
 
-  int do_remove (int fid, const string& who = string ());
-  int do_remove (const octave_value& fid, const string& who = string ());
+  int do_remove (int fid, const std::string& who = std::string ());
+  int do_remove (const octave_value& fid, const std::string& who = std::string ());
 
   void do_clear (void);
 
   string_vector do_get_info (int fid) const;
   string_vector do_get_info (const octave_value& fid) const;
 
-  string do_list_open_files (void) const;
+  std::string do_list_open_files (void) const;
 
   octave_value do_open_file_numbers (void) const;
 
diff --git a/src/oct-strstrm.cc b/src/oct-strstrm.cc
--- a/src/oct-strstrm.cc
+++ b/src/oct-strstrm.cc
@@ -35,7 +35,7 @@
 
   if (! bad ())
     {
-      streambuf *sb = rdbuf ();
+      std::streambuf *sb = rdbuf ();
 
       if (sb)
 	{
@@ -60,7 +60,7 @@
     {
       // XXX FIXME XXX -- shouldn't have to do this!
 
-      streambuf *sb = (const_cast<octave_base_strstream *>(this))->rdbuf ();
+      std::streambuf *sb = (const_cast<octave_base_strstream *>(this))->rdbuf ();
 
       if (sb)
 	{
@@ -82,7 +82,7 @@
 }
 
 octave_stream
-octave_istrstream::create (const string& data, ios::openmode arg_md,
+octave_istrstream::create (const std::string& data, ios::openmode arg_md,
 			   oct_mach_info::float_format flt_fmt)
 {
   return octave_stream (new octave_istrstream (data, arg_md, flt_fmt));
diff --git a/src/oct-strstrm.h b/src/oct-strstrm.h
--- a/src/oct-strstrm.h
+++ b/src/oct-strstrm.h
@@ -48,9 +48,9 @@
 
   // The name of the file.
 
-  string name (void) const { return string (); }
+  std::string name (void) const { return std::string (); }
 
-  virtual streambuf *rdbuf (void) = 0;
+  virtual std::streambuf *rdbuf (void) = 0;
 
   virtual bool bad (void) const = 0;
 
@@ -80,7 +80,7 @@
 		     oct_mach_info::native)
     : octave_base_strstream (arg_md, flt_fmt), is (data) { }
 
-  octave_istrstream (const string& data,
+  octave_istrstream (const std::string& data,
 		     ios::openmode arg_md = ios::out,
 		     oct_mach_info::float_format flt_fmt =
 		     oct_mach_info::native)
@@ -91,18 +91,18 @@
 	  oct_mach_info::float_format flt_fmt = oct_mach_info::native);
 
   static octave_stream
-  create (const string& data, ios::openmode arg_md = ios::out,
+  create (const std::string& data, ios::openmode arg_md = ios::out,
 	  oct_mach_info::float_format flt_fmt = oct_mach_info::native);
 
   // Return non-zero if EOF has been reached on this stream.
 
   bool eof (void) const { return is.eof (); }
 
-  istream *input_stream (void) { return &is; }
+  std::istream *input_stream (void) { return &is; }
 
-  ostream *output_stream (void) { return 0; }
+  std::ostream *output_stream (void) { return 0; }
 
-  streambuf *rdbuf (void) { return is ? is.rdbuf () : 0; }
+  std::streambuf *rdbuf (void) { return is ? is.rdbuf () : 0; }
 
   bool bad (void) const { return is.bad (); }
 
@@ -114,7 +114,7 @@
 
 private:
 
-  istrstream is;
+  std::istrstream is;
 
   // No copying!
 
@@ -141,20 +141,20 @@
 
   bool eof (void) const { return os.eof (); }
 
-  istream *input_stream (void) { return 0; }
+  std::istream *input_stream (void) { return 0; }
 
-  ostream *output_stream (void) { return &os; }
+  std::ostream *output_stream (void) { return &os; }
 
-  string str (void)
+  std::string str (void)
     {
       os << ends;
       char *tmp = os.str ();
-      string retval = tmp;
+      std::string retval = tmp;
       delete [] tmp;
       return retval;
     }
 
-  streambuf *rdbuf (void) { return os ? os.rdbuf () : 0; }
+  std::streambuf *rdbuf (void) { return os ? os.rdbuf () : 0; }
 
   bool bad (void) const { return os.bad (); }
 
@@ -166,7 +166,7 @@
 
 private:
 
-  ostrstream os;
+  std::ostrstream os;
 
   // No copying!
 
diff --git a/src/octave.cc b/src/octave.cc
--- a/src/octave.cc
+++ b/src/octave.cc
@@ -176,7 +176,7 @@
   // This may seem odd, but doing it this way means that we don't have
   // to modify the kpathsea library...
 
-  string odb = octave_env::getenv ("OCTAVE_DB_PATH");
+  std::string odb = octave_env::getenv ("OCTAVE_DB_PATH");
 
   // For backward compatibility.
 
@@ -184,7 +184,7 @@
     odb = octave_env::getenv ("OCTAVE_DB_DIR");
 
   if (odb.empty ())
-    odb = Vdata_dir + string ("/octave:") + Vlibexec_dir + string ("/octave");
+    odb = Vdata_dir + std::string ("/octave:") + Vlibexec_dir + std::string ("/octave");
 
   octave_env::putenv ("TEXMFDBS", odb);
 }
@@ -225,15 +225,15 @@
 
       int home_rc_already_executed = 0;
 
-      string initfile = octave_env::getenv ("OCTAVE_INITFILE");
+      std::string initfile = octave_env::getenv ("OCTAVE_INITFILE");
 
       if (initfile.empty ())
 	initfile = ".octaverc";
 
-      string home_dir = octave_env::get_home_directory ();
+      std::string home_dir = octave_env::get_home_directory ();
 
-      string home_rc = home_dir + "/" + initfile;
-      string local_rc = string ("./") + initfile;
+      std::string home_rc = home_dir + "/" + initfile;
+      std::string local_rc = std::string ("./") + initfile;
 
       if (! home_dir.empty ())
 	{
@@ -531,7 +531,7 @@
 
 	  size_t pos = curr_fcn_file_name.rfind ('/');
 
-	  string tmp = (pos != NPOS)
+	  std::string tmp = (pos != NPOS)
 	    ? curr_fcn_file_name.substr (pos+1) : curr_fcn_file_name;
 
 	  bind_builtin_variable ("program_name", tmp);
diff --git a/src/ov-base-mat.cc b/src/ov-base-mat.cc
--- a/src/ov-base-mat.cc
+++ b/src/ov-base-mat.cc
@@ -63,7 +63,7 @@
 
     default:
       {
-	string n = type_name ();
+	std::string n = type_name ();
 
 	error ("invalid number of indices (%d) for %s value",
 	       len, n.c_str ());
@@ -111,7 +111,7 @@
 
 template <class MT>
 void
-octave_base_matrix<MT>::print (ostream& os, bool pr_as_read_syntax) const
+octave_base_matrix<MT>::print (std::ostream& os, bool pr_as_read_syntax) const
 {
   print_raw (os, pr_as_read_syntax);
   newline (os);
@@ -119,7 +119,7 @@
 
 template <class MT>
 void
-octave_base_matrix<MT>::print_raw (ostream& os, bool pr_as_read_syntax) const
+octave_base_matrix<MT>::print_raw (std::ostream& os, bool pr_as_read_syntax) const
 {
   octave_print_internal (os, matrix, pr_as_read_syntax,
 			 current_print_indent_level ());
@@ -127,7 +127,7 @@
 
 template <class MT>
 bool
-octave_base_matrix<MT>::print_name_tag (ostream& os, const string& name) const
+octave_base_matrix<MT>::print_name_tag (std::ostream& os, const std::string& name) const
 {
   bool retval = false;
 
diff --git a/src/ov-base-mat.h b/src/ov-base-mat.h
--- a/src/ov-base-mat.h
+++ b/src/ov-base-mat.h
@@ -93,11 +93,11 @@
 
   virtual bool print_as_scalar (void) const;
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  bool print_name_tag (ostream& os, const string& name) const;
+  bool print_name_tag (std::ostream& os, const std::string& name) const;
 
 protected:
 
diff --git a/src/ov-base-scalar.cc b/src/ov-base-scalar.cc
--- a/src/ov-base-scalar.cc
+++ b/src/ov-base-scalar.cc
@@ -36,7 +36,7 @@
 
 template <class ST>
 void
-octave_base_scalar<ST>::print (ostream& os, bool pr_as_read_syntax) const
+octave_base_scalar<ST>::print (std::ostream& os, bool pr_as_read_syntax) const
 {
   print_raw (os, pr_as_read_syntax);
   newline (os);
@@ -44,7 +44,7 @@
 
 template <class ST>
 void
-octave_base_scalar<ST>::print_raw (ostream& os, bool pr_as_read_syntax) const
+octave_base_scalar<ST>::print_raw (std::ostream& os, bool pr_as_read_syntax) const
 {
   indent (os);
   octave_print_internal (os, scalar, pr_as_read_syntax);
@@ -52,7 +52,7 @@
 
 template <class ST>
 bool
-octave_base_scalar<ST>::print_name_tag (ostream& os, const string& name) const
+octave_base_scalar<ST>::print_name_tag (std::ostream& os, const std::string& name) const
 {
   indent (os);
   os << name << " = ";
diff --git a/src/ov-base-scalar.h b/src/ov-base-scalar.h
--- a/src/ov-base-scalar.h
+++ b/src/ov-base-scalar.h
@@ -79,11 +79,11 @@
 
   bool is_true (void) const { return (scalar != 0.0); }
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  bool print_name_tag (ostream& os, const string& name) const;
+  bool print_name_tag (std::ostream& os, const std::string& name) const;
 
 protected:
 
diff --git a/src/ov-base.cc b/src/ov-base.cc
--- a/src/ov-base.cc
+++ b/src/ov-base.cc
@@ -55,7 +55,7 @@
 octave_value
 octave_base_value::do_index_op (const octave_value_list&)
 {
-  string nm = type_name ();
+  std::string nm = type_name ();
   error ("can't perform indexing operations for %s type", nm.c_str ());
   return octave_value ();
 }
@@ -63,7 +63,7 @@
 octave_value_list
 octave_base_value::do_index_op (int, const octave_value_list&)
 {
-  string nm = type_name ();
+  std::string nm = type_name ();
   error ("can't perform indexing operations for %s type", nm.c_str ());
   return octave_value ();
 }
@@ -71,35 +71,35 @@
 idx_vector
 octave_base_value::index_vector (void) const
 {
-  string nm = type_name ();
+  std::string nm = type_name ();
   error ("%s type invalid as index value", nm.c_str ());
   return idx_vector ();
 }
 
 octave_value
-octave_base_value::do_struct_elt_index_op (const string&,
+octave_base_value::do_struct_elt_index_op (const std::string&,
 					   const octave_value_list&,
 					   bool)
 {
-  string nm = type_name ();
+  std::string nm = type_name ();
   error ("can't perform indexed structure reference operations for %s type",
 	 nm.c_str ());
   return octave_value ();
 }
 
 octave_value
-octave_base_value::do_struct_elt_index_op (const string&, bool)
+octave_base_value::do_struct_elt_index_op (const std::string&, bool)
 {
-  string nm = type_name ();
+  std::string nm = type_name ();
   error ("can't perform structure reference operations for %s type",
 	 nm.c_str ());
   return octave_value ();
 }
 
 octave_lvalue
-octave_base_value::struct_elt_ref (octave_value *, const string&)
+octave_base_value::struct_elt_ref (octave_value *, const std::string&)
 {
-  string nm = type_name ();
+  std::string nm = type_name ();
   error ("can't perform structure reference operations for %s type",
 	 nm.c_str ());
   return octave_lvalue ();
@@ -122,19 +122,19 @@
 }
 
 void
-octave_base_value::print (ostream&, bool) const
+octave_base_value::print (std::ostream&, bool) const
 {
   gripe_wrong_type_arg ("octave_base_value::print ()", type_name ());
 }
 
 void
-octave_base_value::print_raw (ostream&, bool) const
+octave_base_value::print_raw (std::ostream&, bool) const
 {
   gripe_wrong_type_arg ("octave_base_value::print_raw ()", type_name ());
 }
 
 bool
-octave_base_value::print_name_tag (ostream& os, const string& name) const
+octave_base_value::print_name_tag (std::ostream& os, const std::string& name) const
 {
   indent (os);
   os << name << " =";
@@ -250,7 +250,7 @@
 string
 octave_base_value::string_value (void) const
 {
-  string retval;
+  std::string retval;
   gripe_wrong_type_arg ("octave_base_value::string_value()", type_name ());
   return retval;
 }
diff --git a/src/ov-base.h b/src/ov-base.h
--- a/src/ov-base.h
+++ b/src/ov-base.h
@@ -77,12 +77,12 @@
   idx_vector index_vector (void) const;
 
   octave_value
-  do_struct_elt_index_op (const string& nm, const octave_value_list& idx,
+  do_struct_elt_index_op (const std::string& nm, const octave_value_list& idx,
 			  bool silent);
 
-  octave_value do_struct_elt_index_op (const string& nm, bool silent);
+  octave_value do_struct_elt_index_op (const std::string& nm, bool silent);
 
-  octave_lvalue struct_elt_ref (octave_value *parent, const string& nm);
+  octave_lvalue struct_elt_ref (octave_value *parent, const std::string& nm);
 
   int rows (void) const { return -1; }
 
@@ -177,7 +177,7 @@
 
   string_vector all_strings (void) const;
 
-  string string_value (void) const;
+  std::string string_value (void) const;
 
   Range range_value (void) const;
 
@@ -199,11 +199,11 @@
 
   void convert_to_row_or_column_vector (void);
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  bool print_name_tag (ostream& os, const string& name) const;
+  bool print_name_tag (std::ostream& os, const std::string& name) const;
 
 private:
 
diff --git a/src/ov-builtin.h b/src/ov-builtin.h
--- a/src/ov-builtin.h
+++ b/src/ov-builtin.h
@@ -44,8 +44,8 @@
 
   typedef octave_value_list (*fcn) (const octave_value_list&, int);
 
-  octave_builtin (fcn ff, const string& nm = string (),
-		  const string& ds = string ())
+  octave_builtin (fcn ff, const std::string& nm = std::string (),
+		  const std::string& ds = std::string ())
     : octave_function (nm, ds), f (ff) { }
 
   ~octave_builtin (void) { }
diff --git a/src/ov-cell.cc b/src/ov-cell.cc
--- a/src/ov-cell.cc
+++ b/src/ov-cell.cc
@@ -72,7 +72,7 @@
 
     default:
       {
-	string n = type_name ();
+	std::string n = type_name ();
 
 	error ("invalid number of indices (%d) for %s value",
 	       len, n.c_str ());
@@ -109,13 +109,13 @@
 }
 
 void
-octave_cell::print (ostream& os, bool) const
+octave_cell::print (std::ostream& os, bool) const
 {
   print_raw (os);
 }
 
 void
-octave_cell::print_raw (ostream& os, bool) const
+octave_cell::print_raw (std::ostream& os, bool) const
 {
   unwind_protect::begin_frame ("octave_cell_print");
 
@@ -134,7 +134,7 @@
 	{
 	  for (int i = 0; i < nr; i++)
 	    {
-	      ostrstream buf;
+	      std::ostrstream buf;
 	      buf << "[" << i+1 << "," << j+1 << "]" << ends;
 	      const char *nm = buf.str ();
 
@@ -161,7 +161,7 @@
 }
 
 bool
-octave_cell::print_name_tag (ostream& os, const string& name) const
+octave_cell::print_name_tag (std::ostream& os, const std::string& name) const
 {
   indent (os);
   if (is_empty ())
diff --git a/src/ov-cell.h b/src/ov-cell.h
--- a/src/ov-cell.h
+++ b/src/ov-cell.h
@@ -74,11 +74,11 @@
 
   bool is_constant (void) const { return true; }
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  bool print_name_tag (ostream& os, const string& name) const;
+  bool print_name_tag (std::ostream& os, const std::string& name) const;
 
 private:
 
diff --git a/src/ov-ch-mat.h b/src/ov-ch-mat.h
--- a/src/ov-ch-mat.h
+++ b/src/ov-ch-mat.h
@@ -65,7 +65,7 @@
   octave_char_matrix (const char *s)
     : octave_base_matrix<charMatrix> (s) { }
 
-  octave_char_matrix (const string& s)
+  octave_char_matrix (const std::string& s)
     : octave_base_matrix<charMatrix> (s) { }
 
   octave_char_matrix (const string_vector& s)
diff --git a/src/ov-colon.cc b/src/ov-colon.cc
--- a/src/ov-colon.cc
+++ b/src/ov-colon.cc
@@ -37,14 +37,14 @@
 DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_magic_colon, "magic-colon");
 
 void
-octave_magic_colon::print (ostream& os, bool) const
+octave_magic_colon::print (std::ostream& os, bool) const
 {
   indent (os);
   print_raw (os);
 }
 
 void
-octave_magic_colon::print_raw (ostream& os, bool) const
+octave_magic_colon::print_raw (std::ostream& os, bool) const
 {
   os << ":";
 }
diff --git a/src/ov-colon.h b/src/ov-colon.h
--- a/src/ov-colon.h
+++ b/src/ov-colon.h
@@ -69,9 +69,9 @@
 
   bool valid_as_zero_index (void) const { return false; }
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
 private:
 
diff --git a/src/ov-dld-fcn.cc b/src/ov-dld-fcn.cc
--- a/src/ov-dld-fcn.cc
+++ b/src/ov-dld-fcn.cc
@@ -45,12 +45,12 @@
 
 octave_dld_function::octave_dld_function
   (octave_builtin::fcn ff, const octave_shlib& shl,
-   const string& nm, const string& ds)
+   const std::string& nm, const std::string& ds)
   : octave_builtin (ff, nm, ds), sh_lib (shl)
 {
   mark_fcn_file_up_to_date (time_parsed ());
 
-  string file_name = fcn_file_name ();
+  std::string file_name = fcn_file_name ();
 
   system_fcn_file
     = (! file_name.empty ()
diff --git a/src/ov-dld-fcn.h b/src/ov-dld-fcn.h
--- a/src/ov-dld-fcn.h
+++ b/src/ov-dld-fcn.h
@@ -48,14 +48,14 @@
 public:
 
   octave_dld_function (octave_builtin::fcn ff, const octave_shlib& shl,
-		       const string& nm = string (),
-		       const string& ds = string ());
+		       const std::string& nm = std::string (),
+		       const std::string& ds = std::string ());
 
   ~octave_dld_function (void);
 
   void mark_fcn_file_up_to_date (const octave_time& t) { t_checked = t; }
 
-  string fcn_file_name (void) const;
+  std::string fcn_file_name (void) const;
 
   octave_time time_parsed (void) const;
 
diff --git a/src/ov-fcn.h b/src/ov-fcn.h
--- a/src/ov-fcn.h
+++ b/src/ov-fcn.h
@@ -62,7 +62,7 @@
 
   virtual bool is_system_fcn_file (void) { return false; }
 
-  virtual string fcn_file_name (void) const { return string (); }
+  virtual std::string fcn_file_name (void) const { return std::string (); }
 
   virtual void mark_fcn_file_up_to_date (const octave_time&) { }
 
@@ -72,9 +72,9 @@
   virtual octave_time time_checked (void) const
     { return octave_time (static_cast<time_t> (0)); }
 
-  string name (void) const { return my_name; }
+  std::string name (void) const { return my_name; }
 
-  string doc_string (void) const { return doc; }
+  std::string doc_string (void) const { return doc; }
 
   virtual void unload (void) { }
 
@@ -82,14 +82,14 @@
 
 protected:
 
-  octave_function (const string& nm, const string& ds)
+  octave_function (const std::string& nm, const std::string& ds)
     : my_name (nm), doc (ds) { }
 
   // The name of this function.
-  string my_name;
+  std::string my_name;
 
   // The help text for this function.
-  string doc;
+  std::string doc;
 
 private:
 
diff --git a/src/ov-file.cc b/src/ov-file.cc
--- a/src/ov-file.cc
+++ b/src/ov-file.cc
@@ -55,14 +55,14 @@
 }
 
 void
-octave_file::print (ostream& os, bool) const
+octave_file::print (std::ostream& os, bool) const
 {
   print_raw (os);
   newline (os);
 }
 
 void
-octave_file::print_raw (ostream& os, bool) const
+octave_file::print_raw (std::ostream& os, bool) const
 {
   indent (os); os << "{"; newline (os);
 
@@ -70,11 +70,11 @@
     {
       increment_indent_level ();
 
-      string name = stream.name ();
-      string mode = octave_stream::mode_as_string (stream.mode ());
-      string arch
+      std::string name = stream.name ();
+      std::string mode = octave_stream::mode_as_string (stream.mode ());
+      std::string arch
 	= oct_mach_info::float_format_as_string (stream.float_format ());
-      string status = stream.is_open () ? "open" : "closed";
+      std::string status = stream.is_open () ? "open" : "closed";
 
       indent (os); os << "id = " << number; newline (os);
       indent (os); os << "name = " << name; newline (os);
@@ -89,7 +89,7 @@
 }
 
 bool
-octave_file::print_name_tag (ostream& os, const string& name) const
+octave_file::print_name_tag (std::ostream& os, const std::string& name) const
 {
   indent (os);
   os << name << " =";
diff --git a/src/ov-file.h b/src/ov-file.h
--- a/src/ov-file.h
+++ b/src/ov-file.h
@@ -76,11 +76,11 @@
 
   bool is_stream (void) const { return true; }
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  bool print_name_tag (ostream& os, const string& name) const;
+  bool print_name_tag (std::ostream& os, const std::string& name) const;
 
 private:
 
diff --git a/src/ov-list.cc b/src/ov-list.cc
--- a/src/ov-list.cc
+++ b/src/ov-list.cc
@@ -83,13 +83,13 @@
 }
 
 void
-octave_list::print (ostream& os, bool) const
+octave_list::print (std::ostream& os, bool) const
 {
   print_raw (os);
 }
 
 void
-octave_list::print_raw (ostream& os, bool) const
+octave_list::print_raw (std::ostream& os, bool) const
 {
   unwind_protect::begin_frame ("octave_list_print");
 
@@ -105,7 +105,7 @@
 
       for (int i = 0; i < n; i++)
 	{
-	  ostrstream buf;
+	  std::ostrstream buf;
 	  buf << "[" << i+1 << "]" << ends;
 	  const char *nm = buf.str ();
 
@@ -130,7 +130,7 @@
 }
 
 bool
-octave_list::print_name_tag (ostream& os, const string& name) const
+octave_list::print_name_tag (std::ostream& os, const std::string& name) const
 {
   indent (os);
   if (lst.length () == 0)
diff --git a/src/ov-list.h b/src/ov-list.h
--- a/src/ov-list.h
+++ b/src/ov-list.h
@@ -77,11 +77,11 @@
 
   octave_value_list list_value (void) const { return lst; }
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  bool print_name_tag (ostream& os, const string& name) const;
+  bool print_name_tag (std::ostream& os, const std::string& name) const;
 
 private:
 
diff --git a/src/ov-mapper.h b/src/ov-mapper.h
--- a/src/ov-mapper.h
+++ b/src/ov-mapper.h
@@ -52,8 +52,8 @@
   octave_mapper (ch_mapper ch, d_b_mapper db, c_b_mapper cb,
 		 d_d_mapper dd, d_c_mapper dc,
 		 c_c_mapper cc, double ll, double ul, int f,
-		 const string& nm = string (),
-		 const string& ds = string ())
+		 const std::string& nm = std::string (),
+		 const std::string& ds = std::string ())
     : octave_function (nm, ds), ch_map_fcn (ch),
       d_b_map_fcn (db), c_b_map_fcn (cb),
       d_d_map_fcn (dd), d_c_map_fcn (dc), c_c_map_fcn (cc),
@@ -94,7 +94,7 @@
   //
   //   0  =>  this function returns a matrix of ones and zeros
   //   1  =>  this function returns a numeric matrix (any values)
-  //   2  =>  this function returns a string array
+  //   2  =>  this function returns a std::string array
   //
   // For other mappers, nonzero means that this function can return a
   // complex value for some real arguments.
diff --git a/src/ov-range.cc b/src/ov-range.cc
--- a/src/ov-range.cc
+++ b/src/ov-range.cc
@@ -178,21 +178,21 @@
 }
 
 void
-octave_range::print (ostream& os, bool pr_as_read_syntax) const
+octave_range::print (std::ostream& os, bool pr_as_read_syntax) const
 {
   print_raw (os, pr_as_read_syntax);
   newline (os);
 }
 
 void
-octave_range::print_raw (ostream& os, bool pr_as_read_syntax) const
+octave_range::print_raw (std::ostream& os, bool pr_as_read_syntax) const
 {
   octave_print_internal (os, range, pr_as_read_syntax,
 			 current_print_indent_level ());
 }
 
 bool
-octave_range::print_name_tag (ostream& os, const string& name) const
+octave_range::print_name_tag (std::ostream& os, const std::string& name) const
 {
   bool retval = false;
 
diff --git a/src/ov-range.h b/src/ov-range.h
--- a/src/ov-range.h
+++ b/src/ov-range.h
@@ -139,11 +139,11 @@
 
   octave_value convert_to_str (void) const;
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  bool print_name_tag (ostream& os, const string& name) const;
+  bool print_name_tag (std::ostream& os, const std::string& name) const;
 
 private:
 
diff --git a/src/ov-str-mat.cc b/src/ov-str-mat.cc
--- a/src/ov-str-mat.cc
+++ b/src/ov-str-mat.cc
@@ -189,7 +189,7 @@
 }
 
 void
-octave_char_matrix_str::print_raw (ostream& os, bool pr_as_read_syntax) const
+octave_char_matrix_str::print_raw (std::ostream& os, bool pr_as_read_syntax) const
 {
   octave_print_internal (os, matrix, pr_as_read_syntax,
 			 current_print_indent_level (), true);
diff --git a/src/ov-str-mat.h b/src/ov-str-mat.h
--- a/src/ov-str-mat.h
+++ b/src/ov-str-mat.h
@@ -65,7 +65,7 @@
   octave_char_matrix_str (const char *s)
     : octave_char_matrix (s) { }
 
-  octave_char_matrix_str (const string& s)
+  octave_char_matrix_str (const std::string& s)
     : octave_char_matrix (s) { }
 
   octave_char_matrix_str (const string_vector& s)
@@ -101,11 +101,11 @@
 
   string_vector all_strings (void) const;
 
-  string string_value (void) const;
+  std::string string_value (void) const;
 
   bool print_as_scalar (void) const { return (rows () <= 1); }
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
 private:
 
diff --git a/src/ov-struct.cc b/src/ov-struct.cc
--- a/src/ov-struct.cc
+++ b/src/ov-struct.cc
@@ -41,7 +41,7 @@
 DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA(octave_struct, "struct");
 
 octave_value
-octave_struct::do_struct_elt_index_op (const string& nm,
+octave_struct::do_struct_elt_index_op (const std::string& nm,
 				       const octave_value_list& idx,
 				       bool silent)
 {
@@ -49,7 +49,7 @@
 }
 
 octave_value
-octave_struct::do_struct_elt_index_op (const string& nm, bool silent)
+octave_struct::do_struct_elt_index_op (const std::string& nm, bool silent)
 {
   octave_value retval;
 
@@ -64,19 +64,19 @@
 }
 
 octave_lvalue
-octave_struct::struct_elt_ref (octave_value *, const string& nm)
+octave_struct::struct_elt_ref (octave_value *, const std::string& nm)
 {
   return octave_lvalue (&map [nm]);
 }
 
 void
-octave_struct::print (ostream& os, bool) const
+octave_struct::print (std::ostream& os, bool) const
 {
   print_raw (os);
 }
 
 void
-octave_struct::print_raw (ostream& os, bool) const
+octave_struct::print_raw (std::ostream& os, bool) const
 {
   // XXX FIXME XXX -- would be nice to print the output in some
   // standard order.  Maybe all substructures first, maybe
@@ -96,7 +96,7 @@
 
       for (Pix p = map.first (); p; map.next (p))
 	{
-	  string key = map.key (p);
+	  std::string key = map.key (p);
 	  octave_value val = map.contents (p);
 
 	  val.print_with_name (os, key);
@@ -118,7 +118,7 @@
 }
 
 bool
-octave_struct::print_name_tag (ostream& os, const string& name) const
+octave_struct::print_name_tag (std::ostream& os, const std::string& name) const
 {
   indent (os);
   os << name << " =";
diff --git a/src/ov-struct.h b/src/ov-struct.h
--- a/src/ov-struct.h
+++ b/src/ov-struct.h
@@ -67,12 +67,12 @@
   octave_value *clone (void) { return new octave_struct (*this); }
 
   octave_value
-  do_struct_elt_index_op (const string& nm, const octave_value_list& idx,
+  do_struct_elt_index_op (const std::string& nm, const octave_value_list& idx,
 			  bool silent);
 
-  octave_value do_struct_elt_index_op (const string& nm, bool silent);
+  octave_value do_struct_elt_index_op (const std::string& nm, bool silent);
 
-  octave_lvalue struct_elt_ref (octave_value *parent, const string& nm);
+  octave_lvalue struct_elt_ref (octave_value *parent, const std::string& nm);
 
   bool is_defined (void) const { return true; }
 
@@ -82,11 +82,11 @@
 
   Octave_map map_value (void) const { return map; }
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  bool print_name_tag (ostream& os, const string& name) const;
+  bool print_name_tag (std::ostream& os, const std::string& name) const;
 
 private:
 
diff --git a/src/ov-typeinfo.cc b/src/ov-typeinfo.cc
--- a/src/ov-typeinfo.cc
+++ b/src/ov-typeinfo.cc
@@ -79,7 +79,7 @@
 }
 
 int
-octave_value_typeinfo::register_type (const string& name)
+octave_value_typeinfo::register_type (const std::string& name)
 {
   return (instance_ok ())
     ? instance->do_register_type (name) : -1;
@@ -145,7 +145,7 @@
 }
 
 int
-octave_value_typeinfo::do_register_type (const string& name)
+octave_value_typeinfo::do_register_type (const std::string& name)
 {
   int i = 0;
 
@@ -159,7 +159,7 @@
     {
       len *= 2;
 
-      types.resize (len, string ());
+      types.resize (len, std::string ());
 
       unary_ops.resize (static_cast<int> (octave_value::num_unary_ops),
 			len, static_cast<unary_op_fcn> (0));
diff --git a/src/ov-typeinfo.h b/src/ov-typeinfo.h
--- a/src/ov-typeinfo.h
+++ b/src/ov-typeinfo.h
@@ -44,7 +44,7 @@
 
   static bool instance_ok (void);
 
-  static int register_type (const string&);
+  static int register_type (const std::string&);
 
   static bool register_unary_op (octave_value::unary_op, int, unary_op_fcn);
 
@@ -114,7 +114,7 @@
 protected:
 
   octave_value_typeinfo (void)
-    : num_types (0), types (init_tab_sz, string ()),
+    : num_types (0), types (init_tab_sz, std::string ()),
       unary_ops (octave_value::num_unary_ops, init_tab_sz,
 		 (unary_op_fcn) 0),
       non_const_unary_ops (octave_value::num_unary_ops, init_tab_sz,
@@ -136,7 +136,7 @@
 
   int num_types;
 
-  Array<string> types;
+  Array<std::string> types;
 
   Array2<unary_op_fcn> unary_ops;
 
@@ -152,7 +152,7 @@
 
   Array2<type_conv_fcn> widening_ops;
 
-  int do_register_type (const string&);
+  int do_register_type (const std::string&);
 
   bool do_register_unary_op (octave_value::unary_op, int, unary_op_fcn);
 
diff --git a/src/ov-usr-fcn.cc b/src/ov-usr-fcn.cc
--- a/src/ov-usr-fcn.cc
+++ b/src/ov-usr-fcn.cc
@@ -74,7 +74,7 @@
 octave_user_function::octave_user_function
   (tree_parameter_list *pl, tree_parameter_list *rl,
    tree_statement_list *cl, symbol_table *st)
-  : octave_function (string (), string ()),
+  : octave_function (std::string (), std::string ()),
     param_list (pl), ret_list (rl), cmd_list (cl),
     sym_tab (st), file_name (), fcn_name (),
     t_parsed (static_cast<time_t> (0)),
@@ -136,7 +136,7 @@
       // function file is parsed, it probably doesn't matter that
       // much.
 
-      string ff_name = fcn_file_in_path (file_name);
+      std::string ff_name = fcn_file_in_path (file_name);
 
       if (Vfcn_file_dir.compare (ff_name, 0, Vfcn_file_dir.length ()) == 0)
 	system_fcn_file = 1;
@@ -199,7 +199,7 @@
 }
 
 void
-octave_user_function::stash_function_name (const string& s)
+octave_user_function::stash_function_name (const std::string& s)
 {
   fcn_name = s;
 }
diff --git a/src/ov-usr-fcn.h b/src/ov-usr-fcn.h
--- a/src/ov-usr-fcn.h
+++ b/src/ov-usr-fcn.h
@@ -78,7 +78,7 @@
   void stash_symtab_ptr (symbol_record *sr)
     { symtab_entry = sr; }
 
-  string fcn_file_name (void) const
+  std::string fcn_file_name (void) const
     { return file_name; }
 
   octave_time time_parsed (void) const
@@ -105,9 +105,9 @@
 
   void octave_vr_val (const octave_value& val);
 
-  void stash_function_name (const string& s);
+  void stash_function_name (const std::string& s);
 
-  string function_name (void)
+  std::string function_name (void)
     { return fcn_name; }
 
   void clear_args_passed (void)
@@ -145,10 +145,10 @@
   symbol_table *sym_tab;
 
   // The name of the file we parsed
-  string file_name;
+  std::string file_name;
 
   // The name of the function.
-  string fcn_name;
+  std::string fcn_name;
 
   // The time the file was parsed.
   octave_time t_parsed;
diff --git a/src/ov-va-args.cc b/src/ov-va-args.cc
--- a/src/ov-va-args.cc
+++ b/src/ov-va-args.cc
@@ -37,14 +37,14 @@
 DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_all_va_args, "va-arg");
 
 void
-octave_all_va_args::print (ostream& os, bool) const
+octave_all_va_args::print (std::ostream& os, bool) const
 {
   indent (os);
   print (os);
 }
 
 void
-octave_all_va_args::print_raw (ostream& os, bool) const
+octave_all_va_args::print_raw (std::ostream& os, bool) const
 {
   os << "all_va_args";
 }
diff --git a/src/ov-va-args.h b/src/ov-va-args.h
--- a/src/ov-va-args.h
+++ b/src/ov-va-args.h
@@ -61,9 +61,9 @@
 
   bool is_all_va_args (void) const { return true; }
 
-  void print (ostream& os, bool pr_as_read_syntax = false) const;
+  void print (std::ostream& os, bool pr_as_read_syntax = false) const;
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false) const;
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const;
 
 private:
 
diff --git a/src/ov.cc b/src/ov.cc
--- a/src/ov.cc
+++ b/src/ov.cc
@@ -124,7 +124,7 @@
 string
 octave_value::unary_op_as_string (unary_op op)
 {
-  string retval;
+  std::string retval;
 
   switch (op)
     {
@@ -162,7 +162,7 @@
 string
 octave_value::binary_op_as_string (binary_op op)
 {
-  string retval;
+  std::string retval;
 
   switch (op)
     {
@@ -260,7 +260,7 @@
 string
 octave_value::assign_op_as_string (assign_op op)
 {
-  string retval;
+  std::string retval;
 
   switch (op)
     {
@@ -432,7 +432,7 @@
   maybe_mutate ();
 }
 
-octave_value::octave_value (const string& s)
+octave_value::octave_value (const std::string& s)
   : rep (new octave_char_matrix_str (s))
 {
   rep->count = 1;
@@ -556,22 +556,22 @@
 }
 
 static void
-gripe_no_conversion (const string& on, const string& tn1, const string& tn2)
+gripe_no_conversion (const std::string& on, const std::string& tn1, const std::string& tn2)
 {
   error ("operator %s: no conversion for assignment of `%s' to indexed `%s'",
 	 on.c_str (), tn2.c_str (), tn1.c_str ());
 }
 
 static void
-gripe_assign_failed (const string& on, const string& tn1, const string& tn2)
+gripe_assign_failed (const std::string& on, const std::string& tn1, const std::string& tn2)
 {
   error ("assignment failed for `%s %s %s'",
 	 tn1.c_str (), on.c_str (), tn2.c_str ());
 }
 
 static void
-gripe_assign_failed_or_no_method (const string& on, const string& tn1,
-				  const string& tn2)
+gripe_assign_failed_or_no_method (const std::string& on, const std::string& tn1,
+				  const std::string& tn2)
 {
   error ("assignment failed, or no method for `%s %s %s'",
 	 tn1.c_str (), on.c_str (), tn2.c_str ());
@@ -684,7 +684,7 @@
 }
 
 void
-octave_value::assign_struct_elt (assign_op op, const string& elt_nm,
+octave_value::assign_struct_elt (assign_op op, const std::string& elt_nm,
 				 const octave_value& rhs)
 {
   make_unique ();
@@ -694,7 +694,7 @@
 
 
 void
-octave_value::assign_struct_elt (assign_op op, const string& elt_nm,
+octave_value::assign_struct_elt (assign_op op, const std::string& elt_nm,
 				 const octave_value_list& idx,
 				 const octave_value& rhs)
 {
@@ -704,13 +704,13 @@
 }
 
 octave_lvalue
-octave_value::struct_elt_ref (const string& nm)
+octave_value::struct_elt_ref (const std::string& nm)
 {
   return rep->struct_elt_ref (this, nm);
 }
 
 octave_lvalue
-octave_value::struct_elt_ref (octave_value *, const string&)
+octave_value::struct_elt_ref (octave_value *, const std::string&)
 {
   panic_impossible ();
 
@@ -775,7 +775,7 @@
     }
   else
     {
-      string tn = type_name ();
+      std::string tn = type_name ();
       gripe_invalid_conversion (tn.c_str (), "real column vector");
     }
 
@@ -804,7 +804,7 @@
     }
   else
     {
-      string tn = type_name ();
+      std::string tn = type_name ();
       gripe_invalid_conversion (tn.c_str (), "complex column vector");
     }
 
@@ -833,7 +833,7 @@
     }
   else
     {
-      string tn = type_name ();
+      std::string tn = type_name ();
       gripe_invalid_conversion (tn.c_str (), "real row vector");
     }
 
@@ -862,7 +862,7 @@
     }
   else
     {
-      string tn = type_name ();
+      std::string tn = type_name ();
       gripe_invalid_conversion (tn.c_str (), "complex row vector");
     }
 
@@ -908,7 +908,7 @@
     }
   else
     {
-      string tn = type_name ();
+      std::string tn = type_name ();
       gripe_invalid_conversion (tn.c_str (), "real vector");
     }
 
@@ -952,7 +952,7 @@
     }
   else
     {
-      string tn = type_name ();
+      std::string tn = type_name ();
       gripe_invalid_conversion (tn.c_str (), "complex vector");
     }
 
@@ -960,7 +960,7 @@
 }
 
 void
-octave_value::print_with_name (ostream& output_buf, const string& name,
+octave_value::print_with_name (std::ostream& output_buf, const std::string& name,
 			       bool print_padding) const
 {
   bool pad_after = print_name_tag (output_buf, name);
@@ -972,14 +972,14 @@
 }
 
 static void
-gripe_indexed_assignment (const string& tn1, const string& tn2)
+gripe_indexed_assignment (const std::string& tn1, const std::string& tn2)
 {
   error ("assignment of `%s' to indexed `%s' not implemented",
 	 tn2.c_str (), tn1.c_str ());
 }
 
 static void
-gripe_assign_conversion_failed (const string& tn1, const string& tn2)
+gripe_assign_conversion_failed (const std::string& tn1, const std::string& tn2)
 {
   error ("type conversion for assignment of `%s' to indexed `%s' failed",
 	 tn2.c_str (), tn1.c_str ());
@@ -1144,14 +1144,14 @@
 }
 
 static void
-gripe_binary_op (const string& on, const string& tn1, const string& tn2)
+gripe_binary_op (const std::string& on, const std::string& tn1, const std::string& tn2)
 {
   error ("binary operator `%s' not implemented for `%s' by `%s' operations",
 	 on.c_str (), tn1.c_str (), tn2.c_str ());
 }
 
 static void
-gripe_binary_op_conv (const string& on)
+gripe_binary_op_conv (const std::string& on)
 {
   error ("type conversion failed for binary operator `%s'", on.c_str ());
 }
@@ -1233,14 +1233,14 @@
 }
 
 static void
-gripe_unary_op (const string& on, const string& tn)
+gripe_unary_op (const std::string& on, const std::string& tn)
 {
   error ("unary operator `%s' not implemented for `%s' operands",
 	 on.c_str (), tn.c_str ());
 }
 
 static void
-gripe_unary_op_conv (const string& on)
+gripe_unary_op_conv (const std::string& on)
 {
   error ("type conversion failed for unary operator `%s'", on.c_str ());
 }
@@ -1290,7 +1290,7 @@
 }
 
 static void
-gripe_unary_op_conversion_failed (const string& op, const string& tn)
+gripe_unary_op_conversion_failed (const std::string& op, const std::string& tn)
 {
   error ("operator %s: type conversion for `%s' failed",
 	 op.c_str (), tn.c_str ());
@@ -1361,7 +1361,7 @@
 }
 
 static void
-gripe_unary_op_failed_or_no_method (const string& on, const string& tn)
+gripe_unary_op_failed_or_no_method (const std::string& on, const std::string& tn)
 {
   error ("operator %s: no method, or unable to evaluate for %s operand",
 	 on.c_str (), tn.c_str ());
@@ -1395,7 +1395,7 @@
 // This doesn't need to be fast, but isn't there a better way?
 
 void
-octave_value::indent (ostream& os) const
+octave_value::indent (std::ostream& os) const
 {
   assert (curr_print_indent_level >= 0);
  
@@ -1414,7 +1414,7 @@
 // All print() functions should use this to print new lines.
 
 void
-octave_value::newline (ostream& os) const
+octave_value::newline (std::ostream& os) const
 {
   os << "\n";
 
@@ -1447,7 +1447,7 @@
 
     default:
       {
-	string on = unary_op_as_string (op);
+	std::string on = unary_op_as_string (op);
 	error ("operator %s: no assign operator found", on.c_str ());
       }
     }
@@ -1512,7 +1512,7 @@
 
     default:
       {
-	string on = assign_op_as_string (op);
+	std::string on = assign_op_as_string (op);
 	error ("operator %s: no binary operator found", on.c_str ());
       }
     }
diff --git a/src/ov.h b/src/ov.h
--- a/src/ov.h
+++ b/src/ov.h
@@ -141,11 +141,11 @@
     unknown_assign_op
   };
 
-  static string unary_op_as_string (unary_op);
+  static std::string unary_op_as_string (unary_op);
 
-  static string binary_op_as_string (binary_op);
+  static std::string binary_op_as_string (binary_op);
 
-  static string assign_op_as_string (assign_op);
+  static std::string assign_op_as_string (assign_op);
 
   enum magic_colon { magic_colon_t };
   enum all_va_args { all_va_args_t };
@@ -166,7 +166,7 @@
   octave_value (const boolMatrix& bm);
   octave_value (char c);
   octave_value (const char *s);
-  octave_value (const string& s);
+  octave_value (const std::string& s);
   octave_value (const string_vector& s);
   octave_value (const charMatrix& chm, bool is_string = false);
   octave_value (double base, double limit, double inc);
@@ -245,29 +245,29 @@
 	       const octave_value& rhs);
 
   virtual void
-  assign_struct_elt (assign_op, const string& elt_nm,
+  assign_struct_elt (assign_op, const std::string& elt_nm,
 		     const octave_value& rhs);
 
   virtual void
-  assign_struct_elt (assign_op, const string& elt_nm,
+  assign_struct_elt (assign_op, const std::string& elt_nm,
 		     const octave_value_list& idx, const octave_value& rhs);
 
   virtual idx_vector index_vector (void) const
     { return rep->index_vector (); }
 
   virtual octave_value
-  do_struct_elt_index_op (const string& nm, bool silent = false)
+  do_struct_elt_index_op (const std::string& nm, bool silent = false)
     { return rep->do_struct_elt_index_op (nm, silent); }
 
   virtual octave_value
-  do_struct_elt_index_op (const string& nm, const octave_value_list& idx,
+  do_struct_elt_index_op (const std::string& nm, const octave_value_list& idx,
 			  bool silent = false)
     { return rep->do_struct_elt_index_op (nm, idx, silent); }
 
-  octave_lvalue struct_elt_ref (const string& nm);
+  octave_lvalue struct_elt_ref (const std::string& nm);
 
   virtual octave_lvalue
-  struct_elt_ref (octave_value *parent, const string& nm);
+  struct_elt_ref (octave_value *parent, const std::string& nm);
 
   // Size.
 
@@ -423,7 +423,7 @@
   virtual string_vector all_strings (void) const
     { return rep->all_strings (); }
 
-  virtual string string_value (void) const
+  virtual std::string string_value (void) const
     { return rep->string_value (); }
 
   virtual Range range_value (void) const
@@ -475,21 +475,21 @@
   virtual void convert_to_row_or_column_vector (void)
     { rep->convert_to_row_or_column_vector (); }
 
-  virtual void print (ostream& os, bool pr_as_read_syntax = false) const
+  virtual void print (std::ostream& os, bool pr_as_read_syntax = false) const
     { rep->print (os, pr_as_read_syntax); }
 
-  virtual void print_raw (ostream& os, bool pr_as_read_syntax = false) const
+  virtual void print_raw (std::ostream& os, bool pr_as_read_syntax = false) const
     { rep->print_raw (os, pr_as_read_syntax); }
 
-  virtual bool print_name_tag (ostream& os, const string& name) const
+  virtual bool print_name_tag (std::ostream& os, const std::string& name) const
     { return rep->print_name_tag (os, name); }
 
-  void print_with_name (ostream& os, const string& name,
+  void print_with_name (std::ostream& os, const std::string& name,
 			bool print_padding = true) const;
 
   virtual int type_id (void) const { return rep->type_id (); }
 
-  virtual string type_name (void) const { return rep->type_name (); }
+  virtual std::string type_name (void) const { return rep->type_name (); }
 
   // Unary and binary operations.
 
@@ -523,9 +523,9 @@
   int current_print_indent_level (void) const
     { return curr_print_indent_level; }
 
-  void newline (ostream& os) const;
+  void newline (std::ostream& os) const;
 
-  void indent (ostream& os) const;
+  void indent (std::ostream& os) const;
 
   void reset (void) const;
 
@@ -638,18 +638,18 @@
 #define DECLARE_OV_TYPEID_FUNCTIONS_AND_DATA \
   public: \
     int type_id (void) const { return t_id; } \
-    string type_name (void) const { return t_name; } \
+    std::string type_name (void) const { return t_name; } \
     static volatile int static_type_id (void) { return t_id; } \
     static void register_type (void) \
       { t_id = octave_value_typeinfo::register_type (t_name); } \
  \
   private: \
     static volatile int t_id; \
-    static const string t_name;
+    static const std::string t_name;
 
 #define DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA(t, n) \
   volatile int t::t_id (-1); \
-  const string t::t_name (n)
+  const std::string t::t_name (n)
 
 // If TRUE, allow assignments like
 //
diff --git a/src/pager.cc b/src/pager.cc
--- a/src/pager.cc
+++ b/src/pager.cc
@@ -55,13 +55,13 @@
 static bool write_to_diary_file = false;
 
 // The name of the current diary file.
-static string diary_file;
+static std::string diary_file;
 
 // The diary file.
-static ofstream external_diary_file;
+static std::ofstream external_diary_file;
 
 // The shell command to run as the pager.
-static string Vpager_binary;
+static std::string Vpager_binary;
 
 // TRUE means that if output is going to the pager, it is sent as soon
 // as it is available.  Otherwise, it is buffered and only sent to the
@@ -129,7 +129,7 @@
 	{
 	  if (! external_pager)
 	    {
-	      string pgr = Vpager_binary;
+	      std::string pgr = Vpager_binary;
 
 	      if (! pgr.empty ())
 		{
@@ -278,7 +278,7 @@
 
 octave_pager_stream *octave_pager_stream::instance = 0;
 
-octave_pager_stream::octave_pager_stream (void) : ostream (), pb (0)
+octave_pager_stream::octave_pager_stream (void) : std::ostream (), pb (0)
 {
   pb = new octave_pager_buf;
   rdbuf (pb);
@@ -309,7 +309,7 @@
 
 octave_diary_stream *octave_diary_stream::instance = 0;
 
-octave_diary_stream::octave_diary_stream (void) : ostream (), db (0)
+octave_diary_stream::octave_diary_stream (void) : std::ostream (), db (0)
 {
   db = new octave_diary_buf;
   rdbuf (db);
@@ -429,7 +429,7 @@
 
     case 2:
       {
-	string arg = argv[1];
+	std::string arg = argv[1];
 
 	if (arg == "on")
 	  {
@@ -478,7 +478,7 @@
 
   if (argc == 2)
     {
-      string arg = argv[1];
+      std::string arg = argv[1];
 
       if (arg == "on")
 	bind_builtin_variable ("page_screen_output", 1.0);
@@ -496,18 +496,18 @@
 static string
 default_pager (void)
 {
-  string pager_binary = octave_env::getenv ("PAGER");
+  std::string pager_binary = octave_env::getenv ("PAGER");
 
 #ifdef DEFAULT_PAGER
   if (pager_binary.empty ())
     {
-      pager_binary = string (DEFAULT_PAGER);
+      pager_binary = std::string (DEFAULT_PAGER);
 
       if (pager_binary == "less")
 	{
 	  pager_binary.append (" -e");
 
-	  string lessflags = octave_env::getenv ("LESS");
+	  std::string lessflags = octave_env::getenv ("LESS");
 	  if (lessflags.empty ())
 	    pager_binary.append
 	      (" -P'-- less ?pB(%pB\\%):--. (f)orward, (b)ack, (q)uit$'");
@@ -523,7 +523,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("PAGER");
+  std::string s = builtin_string_variable ("PAGER");
 
   if (s.empty ())
     {
diff --git a/src/pager.h b/src/pager.h
--- a/src/pager.h
+++ b/src/pager.h
@@ -32,11 +32,11 @@
 #endif
 
 class
-octave_pager_buf : public strstreambuf
+octave_pager_buf : public std::strstreambuf
 {
 public:
 
-  octave_pager_buf (int size = 0) : strstreambuf (size) { }
+  octave_pager_buf (int size = 0) : std::strstreambuf (size) { }
 
   void flush_current_contents_to_diary (void);
 
@@ -74,11 +74,11 @@
 };
 
 class
-octave_diary_buf : public strstreambuf
+octave_diary_buf : public std::strstreambuf
 {
 public:
 
-  octave_diary_buf (int size = 0) : strstreambuf (size) { }
+  octave_diary_buf (int size = 0) : std::strstreambuf (size) { }
 
 protected:
 
diff --git a/src/parse.h b/src/parse.h
--- a/src/parse.h
+++ b/src/parse.h
@@ -54,7 +54,7 @@
 extern int current_input_column;
 
 // Buffer for help text snagged from function files.
-extern string help_buf;
+extern std::string help_buf;
 
 // TRUE means we are using readline.
 extern bool line_editing;
@@ -81,25 +81,25 @@
 parse_and_execute (FILE *f);
 
 extern void
-parse_and_execute (const string& s, bool verbose = false,
+parse_and_execute (const std::string& s, bool verbose = false,
 		   const char *warn_for = 0);
 
-extern string get_help_from_file (const string& f);
+extern std::string get_help_from_file (const std::string& f);
 
 extern bool
 load_fcn_from_file (symbol_record *sym_rec, bool exec_script);
 
 extern octave_value_list
-feval (const string& name, const octave_value_list& args, int nargout);
+feval (const std::string& name, const octave_value_list& args, int nargout);
 
 extern octave_value_list
 feval (const octave_value_list& args, int nargout);
 
 extern octave_value_list
-eval_string (const string&, bool silent, int& parse_status, int hargout);
+eval_string (const std::string&, bool silent, int& parse_status, int hargout);
 
 extern octave_value
-eval_string (const string&, bool silent, int& parse_status);
+eval_string (const std::string&, bool silent, int& parse_status);
 
 #endif
 
diff --git a/src/parse.y b/src/parse.y
--- a/src/parse.y
+++ b/src/parse.y
@@ -101,7 +101,7 @@
 int current_input_column = 1;
 
 // Buffer for help text snagged from function files.
-string help_buf;
+std::string help_buf;
 
 // TRUE means we are using readline.
 // (--no-line-editing)
@@ -266,7 +266,7 @@
 
 // Make an indirect reference expression.
 static tree_indirect_ref *
-make_indirect_ref (tree_expression *expr, const string&);
+make_indirect_ref (tree_expression *expr, const std::string&);
 
 // Make a declaration command.
 static tree_decl_command *
@@ -1405,7 +1405,7 @@
 {
   int err_col = current_input_column - 1;
 
-  ostrstream output_buf;
+  std::ostrstream output_buf;
 
   if (reading_fcn_file || reading_script_file)
     output_buf << "parse error near line " << input_line_number
@@ -1626,7 +1626,7 @@
 	{
 	  tree_constant *tc_retval = new tree_constant (tmp);
 
-	  ostrstream buf;
+	  std::ostrstream buf;
 
 	  tree_print_code tpc (buf);
 
@@ -1675,7 +1675,7 @@
 	{
 	  tree_constant *tc_retval = new tree_constant (tmp);
 
-	  ostrstream buf;
+	  std::ostrstream buf;
 
 	  tree_print_code tpc (buf);
 
@@ -1733,7 +1733,7 @@
 		{
 		  tree_constant *tc_retval = new tree_constant (tmp);
 
-		  ostrstream buf;
+		  std::ostrstream buf;
 
 		  tree_print_code tpc (buf);
 
@@ -2370,7 +2370,7 @@
 static octave_user_function *
 frob_function (tree_identifier *id, octave_user_function *fcn)
 {
-  string id_name = id->name ();
+  std::string id_name = id->name ();
 
   // If input is coming from a file, issue a warning if the name of
   // the file does not match the name of the function stated in the
@@ -2404,7 +2404,7 @@
 
       if (Vwarn_future_time_stamp)
 	{
-	  string nm = fcn->fcn_file_name ();
+	  std::string nm = fcn->fcn_file_name ();
 
 	  file_stat fs (nm);
 
@@ -2490,7 +2490,7 @@
 // Make an indirect reference expression.
 
 static tree_indirect_ref *
-make_indirect_ref (tree_expression *expr, const string& elt)
+make_indirect_ref (tree_expression *expr, const std::string& elt)
 {
   tree_indirect_ref *retval = 0;
 
@@ -2565,7 +2565,7 @@
 	{
 	  tree_constant *tc_retval = new tree_constant (tmp);
 
-	  ostrstream buf;
+	  std::ostrstream buf;
 
 	  tree_print_code tpc (buf);
 
@@ -2710,7 +2710,7 @@
 }
 
 void
-parse_and_execute (const string& s, bool verbose, const char *warn_for)
+parse_and_execute (const std::string& s, bool verbose, const char *warn_for)
 {
   unwind_protect::begin_frame ("parse_and_execute_2");
 
@@ -2751,11 +2751,11 @@
 }
 
 static bool
-looks_like_octave_copyright (const string& s)
+looks_like_octave_copyright (const std::string& s)
 {
   bool retval = false;
 
-  string t = s.substr (0, 14);
+  std::string t = s.substr (0, 14);
 
   if (t == "Copyright (C) ")
     {
@@ -2793,7 +2793,7 @@
 static string
 gobble_leading_white_space (FILE *ffile, bool in_parts, bool update_pos)
 {
-  string help_txt;
+  std::string help_txt;
 
   bool first_comments_seen = false;
   bool begin_comment = false;
@@ -2904,9 +2904,9 @@
 }
 
 string
-get_help_from_file (const string& path)
+get_help_from_file (const std::string& path)
 {
-  string retval;
+  std::string retval;
 
   if (! path.empty ())
     {
@@ -2965,7 +2965,7 @@
 }
 
 static bool
-parse_fcn_file (const string& ff, bool exec_script, bool force_script = false)
+parse_fcn_file (const std::string& ff, bool exec_script, bool force_script = false)
 {
   unwind_protect::begin_frame ("parse_fcn_file");
 
@@ -3084,7 +3084,7 @@
 {
   bool script_file_executed = false;
 
-  string nm = sym_rec->name ();
+  std::string nm = sym_rec->name ();
 
   if (octave_dynamic_loader::load (nm))
     {
@@ -3092,7 +3092,7 @@
     }
   else
     {
-      string ff = fcn_file_in_path (nm);
+      std::string ff = fcn_file_in_path (nm);
 
       // These are needed by yyparse.
 
@@ -3130,11 +3130,11 @@
 
   if (nargin == 1)
     {
-      string file_name = args(0).string_value ();
+      std::string file_name = args(0).string_value ();
 
       if (! error_state)
 	{
-	  string file_full_name = file_ops::tilde_expand (file_name);
+	  std::string file_full_name = file_ops::tilde_expand (file_name);
 
 	  unwind_protect::begin_frame ("Fsource");
 
@@ -3162,7 +3162,7 @@
 }
 
 octave_value_list
-feval (const string& name, const octave_value_list& args, int nargout)
+feval (const std::string& name, const octave_value_list& args, int nargout)
 {
   octave_value_list retval;
 
@@ -3181,7 +3181,7 @@
 
   if (args.length () > 0)
     {
-      string name = args(0).string_value ();
+      std::string name = args(0).string_value ();
 
       if (! error_state)
 	{
@@ -3248,7 +3248,7 @@
 }
 
 octave_value_list
-eval_string (const string& s, bool silent, int& parse_status, int nargout)
+eval_string (const std::string& s, bool silent, int& parse_status, int nargout)
 {
   unwind_protect::begin_frame ("eval_string");
 
@@ -3295,7 +3295,7 @@
 }
 
 octave_value
-eval_string (const string& s, bool silent, int& parse_status)
+eval_string (const std::string& s, bool silent, int& parse_status)
 {
   octave_value retval;
 
@@ -3311,11 +3311,11 @@
 eval_string (const octave_value& arg, bool silent, int& parse_status,
 	     int nargout)
 {
-  string s = arg.string_value ();
+  std::string s = arg.string_value ();
 
   if (error_state)
     {
-      error ("eval: expecting string argument");
+      error ("eval: expecting std::string argument");
       return -1.0;
     }
 
diff --git a/src/pr-output.cc b/src/pr-output.cc
--- a/src/pr-output.cc
+++ b/src/pr-output.cc
@@ -73,11 +73,11 @@
 // smaller slices that fit on the screen.
 static bool Vsplit_long_rows;
 
-// Current format string for real numbers and the real part of complex
+// Current format std::string for real numbers and the real part of complex
 // numbers.
 static char *curr_real_fmt = 0;
 
-// Current format string for the imaginary part of complex numbers.
+// Current format std::string for the imaginary part of complex numbers.
 static char *curr_imag_fmt = 0;
 
 // TRUE means don't do any fancy formatting.
@@ -942,7 +942,7 @@
   while (0)
 
 static void
-pr_any_float (const char *fmt, ostream& os, double d, int fw = 0)
+pr_any_float (const char *fmt, std::ostream& os, double d, int fw = 0)
 {
 #if defined (SCO)
   // Apparently on some SCO systems NaN == -0.0 is true.  Compiler bug?
@@ -1058,19 +1058,19 @@
 }
 
 static inline void
-pr_float (ostream& os, double d, int fw = 0)
+pr_float (std::ostream& os, double d, int fw = 0)
 {
   pr_any_float (curr_real_fmt, os, d, fw);
 }
 
 static inline void
-pr_imag_float (ostream& os, double d, int fw = 0)
+pr_imag_float (std::ostream& os, double d, int fw = 0)
 {
   pr_any_float (curr_imag_fmt, os, d, fw);
 }
 
 static void
-pr_complex (ostream& os, const Complex& c, int r_fw = 0, int i_fw = 0)
+pr_complex (std::ostream& os, const Complex& c, int r_fw = 0, int i_fw = 0)
 {
   double r = c.real ();
   pr_float (os, r, r_fw);
@@ -1097,7 +1097,7 @@
 }
 
 static void
-print_empty_matrix (ostream& os, int nr, int nc, bool pr_as_read_syntax)
+print_empty_matrix (std::ostream& os, int nr, int nc, bool pr_as_read_syntax)
 {
   assert (nr == 0 || nc == 0);
 
@@ -1117,7 +1117,7 @@
 }
 
 static void
-pr_scale_header (ostream& os, double scale)
+pr_scale_header (std::ostream& os, double scale)
 {
   if (Vfixed_point_format && scale != 1.0)
     {
@@ -1129,7 +1129,7 @@
 }
 
 static void
-pr_col_num_header (ostream& os, int total_width, int max_width,
+pr_col_num_header (std::ostream& os, int total_width, int max_width,
 		   int lim, int col, int extra_indent)
 {
   if (total_width > max_width && Vsplit_long_rows)
@@ -1154,7 +1154,7 @@
 }
 
 static inline void
-do_plus_format (ostream& os, double d)
+do_plus_format (std::ostream& os, double d)
 {
   if (d == 0.0)
     os << " ";
@@ -1165,7 +1165,7 @@
 }
 
 void
-octave_print_internal (ostream& os, double d, bool pr_as_read_syntax)
+octave_print_internal (std::ostream& os, double d, bool pr_as_read_syntax)
 {
   if (plus_format)
     {
@@ -1182,7 +1182,7 @@
 }
 
 void
-octave_print_internal (ostream& os, const Matrix& m, bool pr_as_read_syntax,
+octave_print_internal (std::ostream& os, const Matrix& m, bool pr_as_read_syntax,
 		       int extra_indent)
 {
   int nr = m.rows ();
@@ -1316,7 +1316,7 @@
 }
 
 static inline void
-do_plus_format (ostream& os, const Complex& c)
+do_plus_format (std::ostream& os, const Complex& c)
 {
   double rp = c.real ();
   double ip = c.imag ();
@@ -1335,7 +1335,7 @@
 }
 
 void
-octave_print_internal (ostream& os, const Complex& c,
+octave_print_internal (std::ostream& os, const Complex& c,
 		       bool pr_as_read_syntax)
 {
   if (plus_format)
@@ -1353,7 +1353,7 @@
 }
 
 void
-octave_print_internal (ostream& os, const ComplexMatrix& cm,
+octave_print_internal (std::ostream& os, const ComplexMatrix& cm,
 		       bool pr_as_read_syntax, int extra_indent)
 {
   int nr = cm.rows ();
@@ -1488,7 +1488,7 @@
 }
 
 void
-octave_print_internal (ostream& os, const Range& r,
+octave_print_internal (std::ostream& os, const Range& r,
 		       bool pr_as_read_syntax, int extra_indent)
 {
   double base = r.base ();
@@ -1594,7 +1594,7 @@
 }
 
 void
-octave_print_internal (ostream& os, const boolMatrix& bm,
+octave_print_internal (std::ostream& os, const boolMatrix& bm,
 		       bool pr_as_read_syntax,
 		       int extra_indent)
 {
@@ -1603,7 +1603,7 @@
 }
 
 void
-octave_print_internal (ostream& os, const charMatrix& chm,
+octave_print_internal (std::ostream& os, const charMatrix& chm,
 		       bool pr_as_read_syntax,
 		       int /* extra_indent XXX FIXME XXX */,
 		       bool pr_as_string)
@@ -1619,7 +1619,7 @@
 	{
 	  for (int i = 0; i < nstr; i++)
 	    {
-	      string row = chm.row_as_string (i);
+	      std::string row = chm.row_as_string (i);
 
 	      if (pr_as_read_syntax)
 		{
@@ -1701,7 +1701,7 @@
 
   if (--argc > 0)
     {
-      string arg = argv[idx++];
+      std::string arg = argv[idx++];
 
       if (arg == "short")
 	{
diff --git a/src/pr-output.h b/src/pr-output.h
--- a/src/pr-output.h
+++ b/src/pr-output.h
@@ -34,35 +34,35 @@
 class charMatrix;
 
 extern void
-octave_print_internal (ostream& os, double d,
+octave_print_internal (std::ostream& os, double d,
 		       bool pr_as_read_syntax = false);
 
 extern void
-octave_print_internal (ostream& os, const Matrix& m,
+octave_print_internal (std::ostream& os, const Matrix& m,
 		       bool pr_as_read_syntax = false,
 		       int extra_indent = 0);
 
 extern void
-octave_print_internal (ostream& os, const Complex& c,
+octave_print_internal (std::ostream& os, const Complex& c,
 		       bool pr_as_read_syntax = false);
 
 extern void
-octave_print_internal (ostream& os, const ComplexMatrix& cm,
+octave_print_internal (std::ostream& os, const ComplexMatrix& cm,
 		       bool pr_as_read_syntax = false,
 		       int extra_indent = 0);
 
 extern void
-octave_print_internal (ostream& os, const Range& r,
+octave_print_internal (std::ostream& os, const Range& r,
 		       bool pr_as_read_syntax = false,
 		       int extra_indent = 0);
 
 extern void
-octave_print_internal (ostream& os, const boolMatrix& m,
+octave_print_internal (std::ostream& os, const boolMatrix& m,
 		       bool pr_as_read_syntax = false,
 		       int extra_indent = 0);
 
 extern void
-octave_print_internal (ostream& os, const charMatrix& chm,
+octave_print_internal (std::ostream& os, const charMatrix& chm,
 		       bool pr_as_read_syntax = false,
 		       int extra_indent = 0,
 		       bool pr_as_string = false);
diff --git a/src/pt-assign.h b/src/pt-assign.h
--- a/src/pt-assign.h
+++ b/src/pt-assign.h
@@ -71,7 +71,7 @@
 
   void eval_error (void);
 
-  string oper (void) const;
+  std::string oper (void) const;
 
   tree_expression *left_hand_side (void) { return lhs; }
 
@@ -139,7 +139,7 @@
 
   void eval_error (void);
 
-  string oper (void) const;
+  std::string oper (void) const;
 
   tree_argument_list *left_hand_side (void) { return lhs; }
 
diff --git a/src/pt-binop.cc b/src/pt-binop.cc
--- a/src/pt-binop.cc
+++ b/src/pt-binop.cc
@@ -199,7 +199,7 @@
 string
 tree_boolean_expression::oper (void) const
 {
-  string retval = "<unknown>";
+  std::string retval = "<unknown>";
 
   switch (etype)
     {
diff --git a/src/pt-binop.h b/src/pt-binop.h
--- a/src/pt-binop.h
+++ b/src/pt-binop.h
@@ -71,7 +71,7 @@
 
   void eval_error (void);
 
-  string oper (void) const;
+  std::string oper (void) const;
 
   tree_expression *lhs (void) { return op_lhs; }
   tree_expression *rhs (void) { return op_rhs; }
@@ -126,7 +126,7 @@
 
   octave_value_list rvalue (int nargout);
 
-  string oper (void) const;
+  std::string oper (void) const;
 
 private:
 
diff --git a/src/pt-check.cc b/src/pt-check.cc
--- a/src/pt-check.cc
+++ b/src/pt-check.cc
@@ -622,7 +622,7 @@
 }
 
 void
-tree_checker::gripe (const string& msg, int line)
+tree_checker::gripe (const std::string& msg, int line)
 {
   if (curr_fcn_file_name.empty ())
     error ("%s", msg.c_str ());
diff --git a/src/pt-check.h b/src/pt-check.h
--- a/src/pt-check.h
+++ b/src/pt-check.h
@@ -129,7 +129,7 @@
 
   bool do_lvalue_check;
 
-  void gripe (const string& msg, int line);
+  void gripe (const std::string& msg, int line);
 
   // No copying!
 
diff --git a/src/pt-cmd.h b/src/pt-cmd.h
--- a/src/pt-cmd.h
+++ b/src/pt-cmd.h
@@ -63,7 +63,7 @@
 {
 public:
 
-  tree_no_op_command (const string& cmd = "no_op", int l = -1, int c = -1)
+  tree_no_op_command (const std::string& cmd = "no_op", int l = -1, int c = -1)
     : tree_command (l, c), orig_cmd (cmd) { }
 
   ~tree_no_op_command (void) { }
@@ -72,11 +72,11 @@
 
   void accept (tree_walker& tw);
 
-  string original_command (void) { return orig_cmd; }
+  std::string original_command (void) { return orig_cmd; }
 
 private:
 
-  string orig_cmd;
+  std::string orig_cmd;
 
   // No copying!
 
diff --git a/src/pt-colon.cc b/src/pt-colon.cc
--- a/src/pt-colon.cc
+++ b/src/pt-colon.cc
@@ -158,7 +158,7 @@
 }
 
 void
-tree_colon_expression::eval_error (const string& s)
+tree_colon_expression::eval_error (const std::string& s)
 {
   if (error_state > 0)
     {
diff --git a/src/pt-colon.h b/src/pt-colon.h
--- a/src/pt-colon.h
+++ b/src/pt-colon.h
@@ -72,7 +72,7 @@
 
   octave_value_list rvalue (int nargout);
 
-  void eval_error (const string& s = string ());
+  void eval_error (const std::string& s = std::string ());
 
   tree_expression *base (void) { return op_base; }
 
diff --git a/src/pt-const.cc b/src/pt-const.cc
--- a/src/pt-const.cc
+++ b/src/pt-const.cc
@@ -42,7 +42,7 @@
 tree_constant::allocator (sizeof (tree_constant), 1024);
 
 void
-tree_constant::print (ostream& os, bool pr_as_read_syntax, bool pr_orig_text)
+tree_constant::print (std::ostream& os, bool pr_as_read_syntax, bool pr_orig_text)
 {
   if (pr_orig_text && ! orig_text.empty ())
     os << orig_text;
@@ -51,7 +51,7 @@
 }
 
 void
-tree_constant::print_raw (ostream& os, bool pr_as_read_syntax,
+tree_constant::print_raw (std::ostream& os, bool pr_as_read_syntax,
 			  bool pr_orig_text) 
 {
   if (pr_orig_text && ! orig_text.empty ())
diff --git a/src/pt-const.h b/src/pt-const.h
--- a/src/pt-const.h
+++ b/src/pt-const.h
@@ -67,10 +67,10 @@
   void maybe_mutate (void)
     { val.maybe_mutate (); }
 
-  void print (ostream& os, bool pr_as_read_syntax = false,
+  void print (std::ostream& os, bool pr_as_read_syntax = false,
 	      bool pr_orig_txt = true);
 
-  void print_raw (ostream& os, bool pr_as_read_syntax = false,
+  void print_raw (std::ostream& os, bool pr_as_read_syntax = false,
 		  bool pr_orig_txt = true);
 
   bool rvalue_ok (void) const
@@ -86,10 +86,10 @@
   // Store the original text corresponding to this constant for later
   // pretty printing.
 
-  void stash_original_text (const string& s)
+  void stash_original_text (const std::string& s)
     { orig_text = s; }
 
-  string original_text (void) const
+  std::string original_text (void) const
     { return orig_text; }
 
 private:
@@ -101,7 +101,7 @@
   octave_value val;
 
   // The original text form of this constant.
-  string orig_text;
+  std::string orig_text;
 
   // No copying!
 
diff --git a/src/pt-decl.h b/src/pt-decl.h
--- a/src/pt-decl.h
+++ b/src/pt-decl.h
@@ -115,10 +115,10 @@
 {
 public:
 
-  tree_decl_command (const string& n, int l = -1, int c = -1)
+  tree_decl_command (const std::string& n, int l = -1, int c = -1)
     : tree_command (l, c), cmd_name (n), initialized (false), init_list (0) { }
 
-  tree_decl_command (const string& n, tree_decl_init_list *t,
+  tree_decl_command (const std::string& n, tree_decl_init_list *t,
 		     int l = -1, int c = -1)
     : tree_command (l, c), cmd_name (n), initialized (false), init_list (t) { }
 
@@ -128,12 +128,12 @@
 
   void accept (tree_walker& tw);
 
-  string name (void) { return cmd_name; }
+  std::string name (void) { return cmd_name; }
 
 protected:
 
   // The name of this command -- global, static, etc.
-  string cmd_name;
+  std::string cmd_name;
 
   // TRUE if this command has been evaluated.
   bool initialized;
diff --git a/src/pt-exp.cc b/src/pt-exp.cc
--- a/src/pt-exp.cc
+++ b/src/pt-exp.cc
@@ -85,7 +85,7 @@
 string
 tree_expression::original_text (void) const
 {
-  return string ();
+  return std::string ();
 }
 
 /*
diff --git a/src/pt-exp.h b/src/pt-exp.h
--- a/src/pt-exp.h
+++ b/src/pt-exp.h
@@ -91,13 +91,13 @@
   bool print_result (void) const
     { return print_flag; }
 
-  virtual string oper (void) const
+  virtual std::string oper (void) const
     { return "<unknown>"; }
 
-  virtual string name (void) const
+  virtual std::string name (void) const
     { return "<unknown>"; }
 
-  virtual string original_text (void) const;
+  virtual std::string original_text (void) const;
 
   tree_expression *mark_in_parens (void)
     {
diff --git a/src/pt-id.cc b/src/pt-id.cc
--- a/src/pt-id.cc
+++ b/src/pt-id.cc
@@ -44,7 +44,7 @@
 string
 tree_identifier::name (void) const
 {
-  string retval;
+  std::string retval;
   if (sym)
     retval = sym->name ();
   return retval;
@@ -58,7 +58,7 @@
 }
 
 void
-tree_identifier::document (const string& s)
+tree_identifier::document (const std::string& s)
 {
   if (sym)
     sym->document (s);
diff --git a/src/pt-id.h b/src/pt-id.h
--- a/src/pt-id.h
+++ b/src/pt-id.h
@@ -59,11 +59,11 @@
   bool is_identifier (void) const
     { return true; }
 
-  string name (void) const;
+  std::string name (void) const;
 
   tree_identifier *define (octave_function *f, unsigned int sym_type);
 
-  void document (const string& s);
+  void document (const std::string& s);
 
   bool is_defined (void);
 
diff --git a/src/pt-idx.h b/src/pt-idx.h
--- a/src/pt-idx.h
+++ b/src/pt-idx.h
@@ -54,7 +54,7 @@
   bool is_index_expression (void) const
     { return true; }
 
-  string name (void) const;
+  std::string name (void) const;
 
   tree_expression *expression (void)
     { return expr; }
diff --git a/src/pt-indir.cc b/src/pt-indir.cc
--- a/src/pt-indir.cc
+++ b/src/pt-indir.cc
@@ -50,7 +50,7 @@
 tree_indirect_ref::name (void) const
 {
   // ??? FIXME ???
-  string xname = expr->name ();
+  std::string xname = expr->name ();
 
   return (xname == "<unknown>") ? xname : xname + "." + nm;
 }
@@ -76,7 +76,7 @@
 	    {
 	      // ??? FIXME ???
 
-	      string xname = name ();
+	      std::string xname = name ();
 
 	      if (xname == "<unknown>")
 		bind_ans (val, true);
diff --git a/src/pt-indir.h b/src/pt-indir.h
--- a/src/pt-indir.h
+++ b/src/pt-indir.h
@@ -46,7 +46,7 @@
   tree_indirect_ref (int l = -1, int c = -1)
     : tree_expression (l, c), expr (0), nm () { }
 
-  tree_indirect_ref (tree_expression *e, const string& n,
+  tree_indirect_ref (tree_expression *e, const std::string& n,
 		     int l = -1, int c = -1)
     : tree_expression (l, c), expr (e), nm (n) { }
 
@@ -55,7 +55,7 @@
   bool is_indirect_ref (void) const
     { return true; }
 
-  string name (void) const;
+  std::string name (void) const;
 
   bool lvalue_ok (void) const
     { return true; }
@@ -69,7 +69,7 @@
   tree_expression *expression (void)
     { return expr; }
 
-  string elt_name (void)
+  std::string elt_name (void)
     { return nm; }
 
   void accept (tree_walker& tw);
@@ -80,7 +80,7 @@
   tree_expression *expr;
 
   // The sub-element name.
-  string nm;
+  std::string nm;
 
   void eval_error (void) const;
 
diff --git a/src/pt-mat.cc b/src/pt-mat.cc
--- a/src/pt-mat.cc
+++ b/src/pt-mat.cc
@@ -585,7 +585,7 @@
 {
   int status = 0;
 
-  string s = builtin_string_variable ("string_fill_char");
+  std::string s = builtin_string_variable ("string_fill_char");
 
   switch (s.length ())
     {
diff --git a/src/pt-mat.h b/src/pt-mat.h
--- a/src/pt-mat.h
+++ b/src/pt-mat.h
@@ -27,7 +27,7 @@
 #pragma interface
 #endif
 
-class ostream;
+#include <iostream>
 
 class octave_value;
 class octave_value_list;
diff --git a/src/pt-plot.cc b/src/pt-plot.cc
--- a/src/pt-plot.cc
+++ b/src/pt-plot.cc
@@ -68,7 +68,7 @@
 static bool Vautomatic_replot;
 
 // The name of the shell command to execute to start gnuplot.
-static string Vgnuplot_binary;
+static std::string Vgnuplot_binary;
 
 // TRUE if gnuplot appears to support multiple plot windows with X11.
 static bool Vgnuplot_has_frames;
@@ -92,7 +92,7 @@
 //
 // XXX FIXME XXX -- this should really be static, but that causes
 // problems on some systems.
-SLStack <string> tmp_files;
+SLStack <std::string> tmp_files;
 
 // Pipe to gnuplot.
 static oprocstream *plot_stream = 0;
@@ -101,14 +101,14 @@
 static pid_t plot_stream_pid = 0;
 
 // Gnuplot command strings that we use.
-static string Vgnuplot_command_plot;
-static string Vgnuplot_command_replot;
-static string Vgnuplot_command_splot;
-static string Vgnuplot_command_using;
-static string Vgnuplot_command_with;
-static string Vgnuplot_command_axes;
-static string Vgnuplot_command_title;
-static string Vgnuplot_command_end;
+static std::string Vgnuplot_command_plot;
+static std::string Vgnuplot_command_replot;
+static std::string Vgnuplot_command_splot;
+static std::string Vgnuplot_command_using;
+static std::string Vgnuplot_command_with;
+static std::string Vgnuplot_command_axes;
+static std::string Vgnuplot_command_title;
+static std::string Vgnuplot_command_end;
 
 static void
 plot_stream_death_handler (pid_t pid, int)
@@ -136,7 +136,7 @@
 
       plot_line_count = 0;
 
-      string plot_prog = Vgnuplot_binary;
+      std::string plot_prog = Vgnuplot_binary;
 
       if (plot_prog.empty ())
 	plot_prog = "gnuplot";
@@ -245,7 +245,7 @@
 
   open_plot_stream ();
 
-  ostrstream plot_buf;
+  std::ostrstream plot_buf;
 
   switch (ndim)
     {
@@ -346,7 +346,7 @@
 }
 
 void
-plot_limits::print (int ndim, ostrstream& plot_buf)
+plot_limits::print (int ndim, std::ostrstream& plot_buf)
 {
   if (ndim  == 2 || ndim == 3)
     {
@@ -378,7 +378,7 @@
 }
 
 void
-plot_range::print (ostrstream& plot_buf)
+plot_range::print (std::ostrstream& plot_buf)
 {
   plot_buf << " [";
 
@@ -501,7 +501,7 @@
 }
 
 int
-subplot_using::print (int ndim, int n_max, ostrstream& plot_buf)
+subplot_using::print (int ndim, int n_max, std::ostrstream& plot_buf)
 {
   int status = eval (ndim, n_max);
 
@@ -534,7 +534,7 @@
 }
 
 int
-subplot_style::print (ostrstream& plot_buf)
+subplot_style::print (std::ostrstream& plot_buf)
 {
   if (! sp_style.empty ())
     {
@@ -626,7 +626,7 @@
 }
 
 int
-subplot_axes::print (ostrstream& plot_buf)
+subplot_axes::print (std::ostrstream& plot_buf)
 {
   if (! sp_axes.empty ())
     plot_buf << " " << Vgnuplot_command_axes << " " << sp_axes;
@@ -682,7 +682,7 @@
 }
 
 int
-subplot::handle_plot_data (int ndim, ostrstream& plot_buf)
+subplot::handle_plot_data (int ndim, std::ostrstream& plot_buf)
 {
   if (sp_plot_data)
     {
@@ -690,7 +690,7 @@
 
       if (! error_state && data.is_defined ())
 	{
-	  string file;
+	  std::string file;
 
 	  if (data.is_string ())
 	    {
@@ -702,7 +702,7 @@
 
 	      file = file_ops::tilde_expand (data.string_value ());
 
-	      ifstream ftmp (file.c_str ());
+	      std::ifstream ftmp (file.c_str ());
 
 	      if (ftmp)
 		{
@@ -769,7 +769,7 @@
 }
 
 int
-subplot::print (int ndim, ostrstream& plot_buf)
+subplot::print (int ndim, std::ostrstream& plot_buf)
 {
   int status = handle_plot_data (ndim, plot_buf);
 
@@ -827,7 +827,7 @@
 }
 
 int
-subplot_list::print (int ndim, ostrstream& plot_buf)
+subplot_list::print (int ndim, std::ostrstream& plot_buf)
 {
   int status = 0;
 
@@ -858,11 +858,11 @@
 string
 save_in_tmp_file (octave_value& t, int ndim, bool parametric)
 {
-  string name = file_ops::tempnam ("", "oct-");
+  std::string name = file_ops::tempnam ("", "oct-");
 
   if (! name.empty ())
     {
-      ofstream file (name.c_str ());
+      std::ofstream file (name.c_str ());
 
       if (file)
 	{
@@ -892,7 +892,7 @@
 }
 
 void
-mark_for_deletion (const string& file)
+mark_for_deletion (const std::string& file)
 {
   tmp_files.push (file);
 }
@@ -902,7 +902,7 @@
 {
   while (! tmp_files.empty ())
     {
-      string filename = tmp_files.pop ();
+      std::string filename = tmp_files.pop ();
       unlink (filename.c_str ());
     }
 }
@@ -923,11 +923,11 @@
 }
 
 void
-do_external_plotter_cd (const string& newdir)
+do_external_plotter_cd (const std::string& newdir)
 {
   if (plot_stream && *plot_stream)
     {
-      ostrstream plot_buf;
+      std::ostrstream plot_buf;
       plot_buf << "cd \"" << newdir << "\"" << Vgnuplot_command_end << ends;
       char *message = plot_buf.str ();
       send_to_plot_stream (message);
@@ -1074,7 +1074,7 @@
 
   if (args.length () == 1 && args(0).is_string ())
     {
-      string cmd = args(0).string_value ();
+      std::string cmd = args(0).string_value ();
 
       if (! (plot_stream && *plot_stream))
 	open_plot_stream ();
@@ -1107,7 +1107,7 @@
   if (error_state)
     return retval;
 
-  ostrstream plot_buf;
+  std::ostrstream plot_buf;
 
   if (argc > 1)
     {
@@ -1118,7 +1118,7 @@
       else if (almost_match ("term", argv[1], 1))
 	{
 	  delete [] gnuplot_terminal_type;
-	  ostrstream buf;
+	  std::ostrstream buf;
 	  int i;
 	  for (i = 2; i < argc-1; i++)
 	    buf << argv[i] << " ";
@@ -1169,7 +1169,7 @@
   if (error_state)
     return retval;
 
-  ostrstream plot_buf;
+  std::ostrstream plot_buf;
 
   int i;
   for (i = 0; i < argc-1; i++)
@@ -1204,11 +1204,11 @@
 }
 
 static int
-set_string_var (string& var, const char *nm)
+set_string_var (std::string& var, const char *nm)
 {
   int retval = 0;
 
-  string s = builtin_string_variable (nm);
+  std::string s = builtin_string_variable (nm);
 
   if (s.empty ())
     {
diff --git a/src/pt-plot.h b/src/pt-plot.h
--- a/src/pt-plot.h
+++ b/src/pt-plot.h
@@ -102,7 +102,7 @@
 
   ~plot_limits (void);
 
-  void print (int ndim, ostrstream& plot_buf);
+  void print (int ndim, std::ostrstream& plot_buf);
 
   plot_range *x_limits (void) { return x_range; }
   plot_range *y_limits (void) { return y_range; }
@@ -135,7 +135,7 @@
 
   ~plot_range (void);
 
-  void print (ostrstream& plot_buf);
+  void print (std::ostrstream& plot_buf);
 
   tree_expression *lower_bound (void) { return lower; }
 
@@ -190,7 +190,7 @@
 
   ColumnVector values (int ndim, int n_max = 0);
 
-  int print (int ndim, int n_max, ostrstream& plot_buf);
+  int print (int ndim, int n_max, std::ostrstream& plot_buf);
 
   int qualifier_count (void) { return qual_count; }
 
@@ -229,17 +229,17 @@
 {
 public:
 
-  subplot_style (const string& s = string (),
+  subplot_style (const std::string& s = std::string (),
 		 tree_expression *lt = 0, tree_expression *pt = 0)
     : sp_style (s), sp_linetype (lt), sp_pointtype (pt) { }
 
   ~subplot_style (void);
 
-  int print (ostrstream& plot_buf);
+  int print (std::ostrstream& plot_buf);
 
   bool columns_ok (int nc);
 
-  string style (void) { return sp_style; }
+  std::string style (void) { return sp_style; }
 
   tree_expression *linetype (void) { return sp_linetype; }
 
@@ -250,7 +250,7 @@
 private:
 
   // The style we are using: `lines', `points', etc.
-  string sp_style;
+  std::string sp_style;
 
   // The number of the line type to use.
   tree_expression *sp_linetype;
@@ -270,21 +270,21 @@
 {
 public:
 
-  subplot_axes (const string& s = string ())
+  subplot_axes (const std::string& s = std::string ())
     : sp_axes (s) { }
 
   ~subplot_axes (void) { }
 
-  int print (ostrstream& plot_buf);
+  int print (std::ostrstream& plot_buf);
 
-  string axes (void) { return sp_axes; }
+  std::string axes (void) { return sp_axes; }
 
   void accept (tree_walker& tw);
 
 private:
 
   // The axes we are using: `x1y1', `x1y2', etc.
-  string sp_axes;
+  std::string sp_axes;
 
   // No copying!
 
@@ -356,9 +356,9 @@
 
   octave_value extract_plot_data (int ndim, octave_value& data);
 
-  int handle_plot_data (int ndim, ostrstream& plot_buf);
+  int handle_plot_data (int ndim, std::ostrstream& plot_buf);
 
-  int print (int ndim, ostrstream& plot_buf);
+  int print (int ndim, std::ostrstream& plot_buf);
 
   tree_expression *plot_data (void) { return sp_plot_data; }
 
@@ -409,7 +409,7 @@
 
   ~subplot_list (void);
 
-  int print (int ndim, ostrstream& plot_buf);
+  int print (int ndim, std::ostrstream& plot_buf);
 
   void accept (tree_walker& tw);
 
@@ -422,16 +422,16 @@
   subplot_list& operator = (const subplot_list&);
 };
 
-extern string save_in_tmp_file (octave_value& t, int ndim = 2,
+extern std::string save_in_tmp_file (octave_value& t, int ndim = 2,
 				bool parametric = false);
 
-extern void mark_for_deletion (const string&);
+extern void mark_for_deletion (const std::string&);
 
 extern void cleanup_tmp_files (void);
 
 extern void close_plot_stream (void);
 
-extern void do_external_plotter_cd (const string& newdir);
+extern void do_external_plotter_cd (const std::string& newdir);
 
 #endif
 
diff --git a/src/pt-pr-code.cc b/src/pt-pr-code.cc
--- a/src/pt-pr-code.cc
+++ b/src/pt-pr-code.cc
@@ -302,9 +302,9 @@
       os << " = ";
     }
 
-  string fcn_name = fcn.function_name ();
+  std::string fcn_name = fcn.function_name ();
 
-  os << (fcn_name.empty () ? string ("(empty)") : fcn_name) << " ";
+  os << (fcn_name.empty () ? std::string ("(empty)") : fcn_name) << " ";
 
   tree_parameter_list *param_list = fcn.parameter_list ();
 
@@ -357,8 +357,8 @@
 
   print_parens (id, "(");
 
-  string nm = id.name ();
-  os << (nm.empty () ? string ("(empty)") : nm);
+  std::string nm = id.name ();
+  os << (nm.empty () ? std::string ("(empty)") : nm);
 
   print_parens (id, ")");
 }
diff --git a/src/pt-pr-code.h b/src/pt-pr-code.h
--- a/src/pt-pr-code.h
+++ b/src/pt-pr-code.h
@@ -40,7 +40,7 @@
 {
 public:
 
-  tree_print_code (ostream& os_arg, const string& pfx = string (),
+  tree_print_code (std::ostream& os_arg, const std::string& pfx = std::string (),
 		   bool pr_orig_txt = true)
     : os (os_arg), prefix (pfx), print_original_text (pr_orig_txt) { }
 
@@ -142,9 +142,9 @@
 
 private:
 
-  ostream& os;
+  std::ostream& os;
 
-  string prefix;
+  std::string prefix;
 
   bool print_original_text;
 
diff --git a/src/pt-unop.h b/src/pt-unop.h
--- a/src/pt-unop.h
+++ b/src/pt-unop.h
@@ -58,7 +58,7 @@
 
   tree_expression *operand (void) { return op; }
 
-  string oper (void) const;
+  std::string oper (void) const;
 
 protected:
 
diff --git a/src/pt.cc b/src/pt.cc
--- a/src/pt.cc
+++ b/src/pt.cc
@@ -41,7 +41,7 @@
 string
 tree::str_print_code (void)
 {
-  ostrstream buf;
+  std::ostrstream buf;
 
   tree_print_code tpc (buf);
 
@@ -51,7 +51,7 @@
 
   const char *s = buf.str ();
 
-  string retval = s;
+  std::string retval = s;
 
   delete [] s;
 
diff --git a/src/pt.h b/src/pt.h
--- a/src/pt.h
+++ b/src/pt.h
@@ -56,7 +56,7 @@
 
   virtual void accept (tree_walker& tw) = 0;
 
-  string str_print_code (void);
+  std::string str_print_code (void);
 
 private:
 
diff --git a/src/symtab.cc b/src/symtab.cc
--- a/src/symtab.cc
+++ b/src/symtab.cc
@@ -61,7 +61,7 @@
 string
 SYMBOL_DEF::type_as_string (void) const
 {
-  string retval = "<unknown type>";
+  std::string retval = "<unknown type>";
 
   if (is_user_variable ())
     retval = "user-defined variable";
@@ -84,18 +84,18 @@
 }
 
 void
-SYMBOL_DEF::type (ostream& os, const string& name, bool pr_type_info,
+SYMBOL_DEF::type (std::ostream& os, const std::string& name, bool pr_type_info,
 		  bool quiet, bool pr_orig_txt)
 {
   if (is_user_function ())
     {
       octave_function *defn = definition.function_value ();
 
-      string fn = defn ? defn->fcn_file_name () : string ();
+      std::string fn = defn ? defn->fcn_file_name () : std::string ();
 
       if (pr_orig_txt && ! fn.empty ())
 	{
-	  ifstream fs (fn.c_str (), ios::in);
+	  std::ifstream fs (fn.c_str (), ios::in);
 
 	  if (fs)
 	    {
@@ -138,9 +138,9 @@
 }
 
 string
-SYMBOL_DEF::which (const string& name)
+SYMBOL_DEF::which (const std::string& name)
 {
-  string retval;
+  std::string retval;
 
   if (is_user_function () || is_dld_function ())
     {
@@ -156,7 +156,7 @@
 }
 
 void
-SYMBOL_DEF::which (ostream& os, const string& name)
+SYMBOL_DEF::which (std::ostream& os, const std::string& name)
 {
   os << name;
 
@@ -164,7 +164,7 @@
     {
       octave_function *defn = definition.function_value ();
 
-      string fn = defn ? defn->fcn_file_name () : string ();
+      std::string fn = defn ? defn->fcn_file_name () : std::string ();
 
       if (! fn.empty ())
 	{
@@ -192,7 +192,7 @@
 // probably be temporarily ignoring interrupts.
 
 void
-symbol_record::rename (const string& new_name)
+symbol_record::rename (const std::string& new_name)
 {
   if (! read_only_error ("rename"))
     nm = new_name;
@@ -445,7 +445,7 @@
 }
 
 void
-symbol_record::print_symbol_info_line (ostream& os)
+symbol_record::print_symbol_info_line (std::ostream& os)
 {
   os << (is_read_only () ? " r-" : " rw")
      << (is_eternal () ? "-" : "d")
@@ -541,7 +541,7 @@
 // A symbol table.
 
 symbol_record *
-symbol_table::lookup (const string& nm, bool insert, bool warn)
+symbol_table::lookup (const std::string& nm, bool insert, bool warn)
 {
   unsigned int index = hash (nm);
 
@@ -570,7 +570,7 @@
 }
 
 void
-symbol_table::rename (const string& old_name, const string& new_name)
+symbol_table::rename (const std::string& old_name, const std::string& new_name)
 {
   unsigned int index = hash (old_name);
 
@@ -627,7 +627,7 @@
 }
 
 bool
-symbol_table::clear (const string& nm, bool clear_user_functions)
+symbol_table::clear (const std::string& nm, bool clear_user_functions)
 {
   unsigned int index = hash (nm);
 
@@ -669,7 +669,7 @@
 }
 
 static bool
-matches_patterns (const string& name, const string_vector& pats)
+matches_patterns (const std::string& name, const string_vector& pats)
 {
   int npats = pats.length ();
 
@@ -706,7 +706,7 @@
 
 	  unsigned int my_type = ptr->type ();
 
-	  string my_name = ptr->name ();
+	  std::string my_name = ptr->name ();
 
 	  if ((type & my_type) && (scope & my_scope)
 	      && matches_patterns (my_name, pats))
@@ -751,15 +751,15 @@
   const symbol_record *a = *(X_CAST (const symbol_record **, a_arg));
   const symbol_record *b = *(X_CAST (const symbol_record **, b_arg));
 
-  string a_nm = a->name ();
-  string b_nm = b->name ();
+  std::string a_nm = a->name ();
+  std::string b_nm = b->name ();
 
   return a_nm.compare (b_nm);
 }
 
 int
 symbol_table::maybe_list (const char *header, const string_vector& argv,
-			  ostream& os, bool show_verbose,
+			  std::ostream& os, bool show_verbose,
 			  unsigned type, unsigned scope)
 {
   int status = 0;
@@ -802,7 +802,7 @@
 }
 
 Array<symbol_record *>
-symbol_table::glob (const string& pat, unsigned int type,
+symbol_table::glob (const std::string& pat, unsigned int type,
 		    unsigned int scope) const
 {
   int count = 0;
@@ -926,7 +926,7 @@
 // Chris Torek's fave hash function.
 
 unsigned int
-symbol_table::hash (const string& str)
+symbol_table::hash (const std::string& str)
 {
   unsigned int h = 0;
 
diff --git a/src/symtab.h b/src/symtab.h
--- a/src/symtab.h
+++ b/src/symtab.h
@@ -124,7 +124,7 @@
       { return (symbol_type & symbol_record::DLD_FUNCTION); }
 
     // XXX FIXME XXX
-    bool is_map_element (const string& /* elts */) const
+    bool is_map_element (const std::string& /* elts */) const
       { return false; }
 
     bool is_defined (void) const
@@ -139,16 +139,16 @@
     int rows (void) const { return definition.rows (); }
     int columns (void) const { return definition.columns (); }
 
-    string type_name (void) const { return definition.type_name (); }
+    std::string type_name (void) const { return definition.type_name (); }
 
-    string type_as_string (void) const;
+    std::string type_as_string (void) const;
 
-    void type (ostream& os, const string& name, bool pr_type_info,
+    void type (std::ostream& os, const std::string& name, bool pr_type_info,
 	       bool quiet, bool pr_orig_txt);
 
-    string which (const string& name);
+    std::string which (const std::string& name);
 
-    void which (ostream& os, const string& name);
+    void which (std::ostream& os, const std::string& name);
 
     void define (const octave_value& val, unsigned int sym_type)
       {
@@ -164,9 +164,9 @@
 
     octave_value& def (void) { return definition; }
 
-    string help (void) const { return help_string; }
+    std::string help (void) const { return help_string; }
 
-    void document (const string& h) { help_string = h; }
+    void document (const std::string& h) { help_string = h; }
 
     unsigned int type (void) { return symbol_type; }
 
@@ -188,7 +188,7 @@
     unsigned int read_only : 1;
 
     // The doc string associated with this variable.
-    string help_string;
+    std::string help_string;
 
     // The value of this definition.  See ov.h and related files.
     octave_value definition;
@@ -219,20 +219,20 @@
       nm (), chg_fcn (0), definition (new symbol_def ()),
       next_elem (0) { }
 
-  symbol_record (const string& n, symbol_record *nxt)
+  symbol_record (const std::string& n, symbol_record *nxt)
     : formal_param (0), linked_to_global (0), tagged_static (0),
       nm (n), chg_fcn (0), definition (new symbol_def ()),
       next_elem (nxt) { }
 
   ~symbol_record (void) { }
 
-  string name (void) const { return nm; }
+  std::string name (void) const { return nm; }
 
-  string help (void) const { return definition->help (); }
+  std::string help (void) const { return definition->help (); }
 
   octave_value& def (void) { return definition->def (); }
 
-  void rename (const string& new_name);
+  void rename (const std::string& new_name);
 
   bool is_function (void) const
     { return definition->is_function (); }
@@ -267,7 +267,7 @@
   bool is_builtin_variable (void) const
     { return definition->is_builtin_variable (); }
 
-  bool is_map_element (const string& elts) const
+  bool is_map_element (const std::string& elts) const
     { return definition->is_map_element (elts); }
 
   unsigned int type (void) const { return definition->type (); }
@@ -294,7 +294,7 @@
 
   bool define (octave_function *f, unsigned int sym_type);
 
-  void document (const string& h) { definition->document (h); }
+  void document (const std::string& h) { definition->document (h); }
 
   void clear (void);
 
@@ -315,17 +315,17 @@
   int rows (void) const { return definition->rows (); }
   int columns (void) const { return definition->columns (); }
 
-  string type_name (void) const { return definition->type_name (); }
+  std::string type_name (void) const { return definition->type_name (); }
 
-  string type_as_string (void) const
+  std::string type_as_string (void) const
     { return definition->type_as_string (); }
 
-  void type (ostream& os, bool pr_type_info, bool quiet, bool pr_orig_txt)
+  void type (std::ostream& os, bool pr_type_info, bool quiet, bool pr_orig_txt)
     { definition->type (os, name (), pr_type_info, quiet, pr_orig_txt); }
 
-  string which (void) { return definition->which (name ()); }
+  std::string which (void) { return definition->which (name ()); }
 
-  void which (ostream& os) { definition->which (os, name ()); }
+  void which (std::ostream& os) { definition->which (os, name ()); }
 
   octave_value& variable_value (void);
   octave_lvalue variable_reference (void);
@@ -338,7 +338,7 @@
 
   void pop_context (void);
 
-  void print_symbol_info_line (ostream& os);
+  void print_symbol_info_line (std::ostream& os);
 
   void dump_symbol_info (void);
 
@@ -348,7 +348,7 @@
   unsigned int linked_to_global : 1;
   unsigned int tagged_static : 1;
 
-  string nm;
+  std::string nm;
   change_function chg_fcn;
   symbol_def *definition;
   symbol_record *next_elem;
@@ -410,13 +410,13 @@
     delete [] table;
   }
 
-  symbol_record *lookup (const string& nm, bool insert = false,
+  symbol_record *lookup (const std::string& nm, bool insert = false,
 			 bool warn = false);
 
-  void rename (const string& old_name, const string& new_name);
+  void rename (const std::string& old_name, const std::string& new_name);
 
   void clear (bool clear_user_functions = true);
-  bool clear (const string& nm, bool clear_user_functions = true);
+  bool clear (const std::string& nm, bool clear_user_functions = true);
 
   int size (void) const;
 
@@ -433,10 +433,10 @@
 
 
   int maybe_list (const char *header, const string_vector& argv,
-		  ostream& os, bool show_verbose,
+		  std::ostream& os, bool show_verbose,
 		  unsigned type, unsigned scope);
   
-  Array<symbol_record *> glob (const string& pat = string ("*"),
+  Array<symbol_record *> glob (const std::string& pat = std::string ("*"),
 			       unsigned int type = SYMTAB_ALL_TYPES,
 			       unsigned int scope = SYMTAB_ALL_SCOPES) const;
 
@@ -452,7 +452,7 @@
 
   symbol_record *table;
 
-  unsigned int hash (const string& s);
+  unsigned int hash (const std::string& s);
 
   // No copying!
 
diff --git a/src/syscalls.cc b/src/syscalls.cc
--- a/src/syscalls.cc
+++ b/src/syscalls.cc
@@ -101,7 +101,7 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
@@ -123,7 +123,7 @@
 
 	      if (i_old >= 0 && i_new >= 0)
 		{
-		  string msg;
+		  std::string msg;
 
 		  int status = octave_syscalls::dup2 (i_old, i_new, msg);
 
@@ -162,14 +162,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
 
   if (nargin == 1 || nargin == 2)
     {
-      string exec_file = args(0).string_value ();
+      std::string exec_file = args(0).string_value ();
 
       if (! error_state)
 	{
@@ -202,7 +202,7 @@
 
 	  if (! error_state)
 	    {
-	      string msg;
+	      std::string msg;
 
 	      int status = octave_syscalls::execvp (exec_file, exec_args, msg);
 
@@ -275,7 +275,7 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
@@ -293,7 +293,7 @@
 	    error ("fcntl: invalid file id");
 	  else
 	    {
-	      string msg;
+	      std::string msg;
 
 	      int status = octave_syscalls::fcntl (fid, req, arg, msg);
 
@@ -335,14 +335,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
 
   if (nargin == 0)
     {
-      string msg;
+      std::string msg;
 
       pid_t pid = octave_syscalls::fork (msg);
 
@@ -363,14 +363,14 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
 
   if (nargin == 0)
     {
-      string msg;
+      std::string msg;
 
       retval(0) = static_cast<double> (octave_syscalls::getpgrp (msg));
       retval(1) = msg;
@@ -499,7 +499,7 @@
 
   if (args.length () == 1)
     {
-      string fname = file_ops::tilde_expand (args(0).string_value ());
+      std::string fname = file_ops::tilde_expand (args(0).string_value ());
 
       if (! error_state)
 	{
@@ -507,7 +507,7 @@
 
 	  if (fs)
 	    {
-	      retval(2) = string ();
+	      retval(2) = std::string ();
 	      retval(1) = 0.0;
 	      retval(0) = octave_value (mk_stat_map (fs));
 	    }
@@ -539,7 +539,7 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
@@ -548,13 +548,13 @@
     {
       if (args(0).is_string ())
 	{
-	  string name = args(0).string_value ();
+	  std::string name = args(0).string_value ();
 
 	  if (args(1).is_scalar_type ())
 	    {
 	      long mode = static_cast<long> (args(1).double_value ());
 
-	      string msg;
+	      std::string msg;
 
 	      int status = file_ops::mkfifo (name, mode, msg);
 
@@ -588,7 +588,7 @@
 {
   octave_value_list retval;
 
-  retval(2) = string ();
+  retval(2) = std::string ();
   retval(1) = -1.0;
   retval(0) = Matrix ();
 
@@ -598,7 +598,7 @@
     {
       int fid[2];
 
-      string msg;
+      std::string msg;
 
       int status = octave_syscalls::pipe (fid, msg);
 
@@ -609,8 +609,8 @@
 	  FILE *ifile = fdopen (fid[0], "r");
 	  FILE *ofile = fdopen (fid[1], "w");
 
-	  octave_stream is = octave_istdiostream::create (string (), ifile);
-	  octave_stream os = octave_ostdiostream::create (string (), ofile);
+	  octave_stream is = octave_istdiostream::create (std::string (), ifile);
+	  octave_stream os = octave_ostdiostream::create (std::string (), ofile);
 
 	  octave_value_list file_ids;
 
@@ -719,7 +719,7 @@
 
   if (args.length () == 1)
     {
-      string fname = file_ops::tilde_expand (args(0).string_value ());
+      std::string fname = file_ops::tilde_expand (args(0).string_value ());
 
       if (! error_state)
 	{
@@ -727,7 +727,7 @@
 
 	  if (fs)
 	    {
-	      retval(2) = string ();
+	      retval(2) = std::string ();
 	      retval(1) = 0.0;
 	      retval(0) = octave_value (mk_stat_map (fs));
 	    }
@@ -757,7 +757,7 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
@@ -766,9 +766,9 @@
     {
       if (args(0).is_string ())
 	{
-	  string name = args(0).string_value ();
+	  std::string name = args(0).string_value ();
 
-	  string msg;
+	  std::string msg;
 
 	  int status = file_ops::unlink (name, msg);
 
@@ -827,7 +827,7 @@
 {
   octave_value_list retval;
 
-  retval(1) = string ();
+  retval(1) = std::string ();
   retval(0) = -1.0;
 
   int nargin = args.length ();
@@ -855,7 +855,7 @@
 
 	  if (! error_state)
 	    {
-	      string msg;
+	      std::string msg;
 
 	      pid_t status = octave_syscalls::waitpid (pid, options, msg);
 
diff --git a/src/sysdep.cc b/src/sysdep.cc
--- a/src/sysdep.cc
+++ b/src/sysdep.cc
@@ -351,7 +351,7 @@
 
   if (nargin == 1)
     {
-      string name = args(0).string_value ();
+      std::string name = args(0).string_value ();
 
       if (! error_state)
 	retval = octave_env::getenv (name);
@@ -374,11 +374,11 @@
 
   if (nargin == 2)
     {
-      string var = args(0).string_value (); 
+      std::string var = args(0).string_value (); 
 
       if (! error_state)
 	{
-	  string val = args(1).string_value (); 
+	  std::string val = args(1).string_value (); 
 
 	  if (! error_state)
 	    octave_env::putenv (var, val);
diff --git a/src/token.cc b/src/token.cc
--- a/src/token.cc
+++ b/src/token.cc
@@ -43,15 +43,15 @@
   type_tag = generic_token;
 }
 
-token::token (const string& s, int l, int c)
+token::token (const std::string& s, int l, int c)
 {
   line_num = l;
   column_num = c;
   type_tag = string_token;
-  str = new string (s);
+  str = new std::string (s);
 }
 
-token::token (double d, const string& s, int l, int c)
+token::token (double d, const std::string& s, int l, int c)
 {
   line_num = l;
   column_num = c;
diff --git a/src/token.h b/src/token.h
--- a/src/token.h
+++ b/src/token.h
@@ -65,8 +65,8 @@
     };
 
   token (int l = -1, int c = -1);
-  token (const string& s, int l = -1, int c = -1);
-  token (double d, const string& s = string (), int l = -1, int c = -1);
+  token (const std::string& s, int l = -1, int c = -1);
+  token (double d, const std::string& s = std::string (), int l = -1, int c = -1);
   token (end_tok_type t, int l = -1, int c = -1);
   token (plot_tok_type t, int l = -1, int c = -1);
   token (symbol_record *s, int l = -1, int c = -1);
@@ -76,13 +76,13 @@
   int line (void) { return line_num; }
   int column (void) { return column_num; }
 
-  string text (void);
+  std::string text (void);
   double number (void);
   end_tok_type ettype (void);
   plot_tok_type pttype (void);
   symbol_record *sym_rec (void);
 
-  string text_rep (void);
+  std::string text_rep (void);
 
 private:
   token (const token& tok);
@@ -93,13 +93,13 @@
   token_type type_tag;
   union
     {
-      string *str;
+      std::string *str;
       double num;
       end_tok_type et;
       plot_tok_type pt;
       symbol_record *sr;
     };
-  string orig_text;
+  std::string orig_text;
 };
 
 #endif
diff --git a/src/toplev.cc b/src/toplev.cc
--- a/src/toplev.cc
+++ b/src/toplev.cc
@@ -222,7 +222,7 @@
   if (nargin != 0)
     warning ("computer: ignoring extra arguments");
 
-  string msg;
+  std::string msg;
 
   if (strcmp (CANONICAL_HOST_TYPE, "unknown") == 0)
     msg = "Hi Dave, I'm a HAL-9000";
@@ -312,7 +312,7 @@
 }
 
 static octave_value_list
-run_command_and_return_output (const string& cmd_str)
+run_command_and_return_output (const std::string& cmd_str)
 {
   octave_value_list retval;
 
@@ -324,7 +324,7 @@
 
       if (*cmd)
 	{
-	  ostrstream output_buf;
+	  std::ostrstream output_buf;
 
 	  // XXX FIXME XXX -- sometimes, the subprocess hasn't written
 	  // anything before we try to read from the procstream.  The
@@ -424,7 +424,7 @@
     {
       bool return_output = (nargout > 0 || nargin > 1);
 
-      string cmd_str = args(0).string_value ();
+      std::string cmd_str = args(0).string_value ();
 
       enum exec_type { sync, async };
 
@@ -434,7 +434,7 @@
 	{
 	  if (nargin > 2)
 	    {
-	      string type_str = args(2).string_value ();
+	      std::string type_str = args(2).string_value ();
 
 	      if (! error_state)
 		{
@@ -450,7 +450,7 @@
 	    }
 	}
       else
-	error ("system: expecting string as first argument");
+	error ("system: expecting std::string as first argument");
 
       if (! error_state)
 	{
@@ -500,7 +500,7 @@
 
 // XXX FIXME XXX -- this should really be static, but that causes
 // problems on some systems.
-SLStack<string> octave_atexit_functions;
+SLStack<std::string> octave_atexit_functions;
 
 void
 do_octave_atexit (void)
@@ -566,7 +566,7 @@
   if (nargin == 1)
     {
 #if defined (HAVE_ATEXIT) || defined (HAVE_ON_EXIT)
-      string arg = args(0).string_value ();
+      std::string arg = args(0).string_value ();
 
       if (! error_state)
 	octave_atexit_functions.push (arg);
@@ -654,7 +654,7 @@
 
   if (nargin == 1)
     {
-      string arg = args(0).string_value ();
+      std::string arg = args(0).string_value ();
 
       if (! error_state)
 	retval = octave_value (m [arg.c_str ()]);
diff --git a/src/unwind-prot.cc b/src/unwind-prot.cc
--- a/src/unwind-prot.cc
+++ b/src/unwind-prot.cc
@@ -62,7 +62,7 @@
 
   saved_variable (int *p, int v);
 
-  saved_variable (string *p, const string& v);
+  saved_variable (std::string *p, const std::string& v);
 
   saved_variable (void **p, void *v);
 
@@ -86,7 +86,7 @@
     {
       bool bool_value;
       int int_value;
-      const string *str_value;
+      const std::string *str_value;
       void *gen_ptr_value;
     };
 
@@ -119,11 +119,11 @@
   size = sizeof (int);  // Is this necessary?
 }
 
-saved_variable::saved_variable (string *p, const string& v)
+saved_variable::saved_variable (std::string *p, const std::string& v)
 {
   type_tag = string_type;
   gen_ptr = p;
-  str_value = new string (v);
+  str_value = new std::string (v);
   size = sizeof (string);  // Is this necessary?
 }
 
@@ -167,7 +167,7 @@
       break;
 
     case string_type:
-      (static_cast<string *> (gen_ptr)) -> assign (*str_value);
+      (static_cast<std::string *> (gen_ptr)) -> assign (*str_value);
       break;
 
     case generic_ptr:
@@ -217,14 +217,14 @@
 }
 
 void
-unwind_protect::begin_frame (const string& tag)
+unwind_protect::begin_frame (const std::string& tag)
 {
   unwind_elem elem (tag);
   list.push (elem);
 }
 
 void
-unwind_protect::run_frame (const string& tag)
+unwind_protect::run_frame (const std::string& tag)
 {
   while (! list.empty ())
     {
@@ -241,7 +241,7 @@
 }
 
 void
-unwind_protect::discard_frame (const string& tag)
+unwind_protect::discard_frame (const std::string& tag)
 {
   while (! list.empty ())
     {
@@ -287,7 +287,7 @@
 }
 
 void
-unwind_protect::save_str (string *ptr, const string& value)
+unwind_protect::save_str (std::string *ptr, const std::string& value)
 {
   saved_variable *s = new saved_variable (ptr, value);
   add (saved_variable::restore, s);
diff --git a/src/unwind-prot.h b/src/unwind-prot.h
--- a/src/unwind-prot.h
+++ b/src/unwind-prot.h
@@ -43,7 +43,7 @@
   unwind_elem (void)
     : ue_tag (), ue_fptr (0), ue_ptr (0) { }
 
-  unwind_elem (const string &t)
+  unwind_elem (const std::string &t)
     : ue_tag (t), ue_fptr (0), ue_ptr (0) { }
 
   unwind_elem (cleanup_func f, void *p)
@@ -63,7 +63,7 @@
       return *this;
     }
 
-  string tag (void) { return ue_tag; }
+  std::string tag (void) { return ue_tag; }
 
   cleanup_func fptr (void) { return ue_fptr; }
 
@@ -71,7 +71,7 @@
 
 private:
 
-  string ue_tag;
+  std::string ue_tag;
 
   cleanup_func ue_fptr;
 
@@ -89,11 +89,11 @@
 
   static void discard (void);
 
-  static void begin_frame (const string& tag);
+  static void begin_frame (const std::string& tag);
 
-  static void run_frame (const string& tag);
+  static void run_frame (const std::string& tag);
 
-  static void discard_frame (const string& tag);
+  static void discard_frame (const std::string& tag);
 
   static void run_all (void);
 
@@ -105,7 +105,7 @@
 
   static void save_int (int *ptr, int value);
 
-  static void save_str (string *ptr, const string& value);
+  static void save_str (std::string *ptr, const std::string& value);
 
   static void save_ptr (void **ptr, void *value);
 
diff --git a/src/utils.cc b/src/utils.cc
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -95,7 +95,7 @@
 }
 
 int
-almost_match (const string& std, const string& s, int min_match_len,
+almost_match (const std::string& std, const std::string& s, int min_match_len,
 	      int case_sens)
 {
   int stdlen = std.length ();
@@ -111,7 +111,7 @@
 // Ugh.
 
 int
-keyword_almost_match (const char * const *std, int *min_len, const string& s,
+keyword_almost_match (const char * const *std, int *min_len, const std::string& s,
 		      int min_toks_to_match, int max_toks)
 {
   int status = 0;
@@ -229,7 +229,7 @@
 // See if the given file is in the path.
 
 string
-search_path_for_file (const string& path, const string& name)
+search_path_for_file (const std::string& path, const std::string& name)
 {
   dir_path p (path);
 
@@ -290,7 +290,7 @@
 
   if (argc == 3)
     {
-      string fname = search_path_for_file (argv[1], argv[2]);
+      std::string fname = search_path_for_file (argv[1], argv[2]);
 
       if (fname.empty ())
 	retval = Matrix ();
@@ -304,9 +304,9 @@
 }
 
 string
-file_in_path (const string& name, const string& suffix)
+file_in_path (const std::string& name, const std::string& suffix)
 {
-  string nm = name;
+  std::string nm = name;
 
   if (! suffix.empty ())
     nm.append (suffix);
@@ -319,9 +319,9 @@
 // full path to the file.
 
 string
-fcn_file_in_path (const string& name)
+fcn_file_in_path (const std::string& name)
 {
-  string retval;
+  std::string retval;
 
   int len = name.length ();
   
@@ -340,9 +340,9 @@
 // full path to the file.
 
 string
-oct_file_in_path (const string& name)
+oct_file_in_path (const std::string& name)
 {
-  string retval;
+  std::string retval;
 
   int len = name.length ();
   
@@ -361,9 +361,9 @@
 // Replace backslash escapes in a string with the real values.
 
 string
-do_string_escapes (const string& s)
+do_string_escapes (const std::string& s)
 {
-  string retval;
+  std::string retval;
 
   size_t i = 0;
   size_t j = 0;
@@ -507,9 +507,9 @@
 }
 
 string
-undo_string_escapes (const string& s)
+undo_string_escapes (const std::string& s)
 {
-  string retval;
+  std::string retval;
 
   for (size_t i = 0; i < s.length (); i++)
     retval.append (undo_string_escape (s[i]));
@@ -563,7 +563,7 @@
 }
 
 static void
-warn_old_style_preference (bool val, const string& sval)
+warn_old_style_preference (bool val, const std::string& sval)
 {
   warning
     ("preference of \"%s\" is obsolete -- use numeric value of %d instead",
@@ -578,11 +578,11 @@
 //   return of -1 => ok, but give me warning (default).
 
 int
-check_preference (const string& var)
+check_preference (const std::string& var)
 {
   int pref = -1;
 
-  string val = builtin_string_variable (var);
+  std::string val = builtin_string_variable (var);
 
   if (val.empty ())
     {
diff --git a/src/utils.h b/src/utils.h
--- a/src/utils.h
+++ b/src/utils.h
@@ -32,30 +32,30 @@
 class octave_value_list;
 class string_vector;
 
-extern string search_path_for_file (const string&, const string&);
-extern string file_in_path (const string&, const string&);
-extern string fcn_file_in_path (const string&);
-extern string oct_file_in_path (const string&);
+extern std::string search_path_for_file (const std::string&, const std::string&);
+extern std::string file_in_path (const std::string&, const std::string&);
+extern std::string fcn_file_in_path (const std::string&);
+extern std::string oct_file_in_path (const std::string&);
 
 extern void jump_to_top_level (void) GCC_ATTR_NORETURN;
 
-extern int almost_match (const string& std, const string& s,
+extern int almost_match (const std::string& std, const std::string& s,
 			 int min_match_len = 1, int case_sens = 1);
 
 extern int
 keyword_almost_match (const char * const *std, int *min_len,
-		      const string& s, int min_toks_to_match,
+		      const std::string& s, int min_toks_to_match,
 		      int max_toks);
 
 extern int empty_arg (const char *name, int nr, int nc);
 
 extern const char *undo_string_escape (char c);
 
-extern string do_string_escapes (const string& s);
+extern std::string do_string_escapes (const std::string& s);
 
-extern string undo_string_escapes (const string& s);
+extern std::string undo_string_escapes (const std::string& s);
 
-extern int check_preference (const string& var);
+extern int check_preference (const std::string& var);
 
 extern void
 get_dimensions (const octave_value& a, const octave_value& b,
diff --git a/src/variables.cc b/src/variables.cc
--- a/src/variables.cc
+++ b/src/variables.cc
@@ -88,7 +88,7 @@
 // Is this variable a builtin?
 
 bool
-is_builtin_variable (const string& name)
+is_builtin_variable (const std::string& name)
 {
   symbol_record *sr = global_sym_tab->lookup (name);
   return (sr && sr->is_builtin_variable ());
@@ -97,7 +97,7 @@
 // Is this a text-style function?
 
 bool
-is_text_function_name (const string& s)
+is_text_function_name (const std::string& s)
 {
   symbol_record *sr = global_sym_tab->lookup (s);
   return (sr && sr->is_text_function ());
@@ -106,7 +106,7 @@
 // Is this a built-in function?
 
 bool
-is_builtin_function_name (const string& s)
+is_builtin_function_name (const std::string& s)
 {
   symbol_record *sr = global_sym_tab->lookup (s);
   return (sr && sr->is_builtin_function ());
@@ -115,7 +115,7 @@
 // Is this a mapper function?
 
 bool
-is_mapper_function_name (const string& s)
+is_mapper_function_name (const std::string& s)
 {
   symbol_record *sr = global_sym_tab->lookup (s);
   return (sr && sr->is_mapper_function ());
@@ -124,7 +124,7 @@
 // Is this function globally in this scope?
 
 bool
-is_globally_visible (const string& name)
+is_globally_visible (const std::string& name)
 {
   symbol_record *sr = curr_sym_tab->lookup (name);
   return (sr && sr->is_linked_to_global ());
@@ -133,7 +133,7 @@
 // Is this octave_value a valid function?
 
 octave_function *
-is_valid_function (const string& fcn_name, const string& warn_for, bool warn)
+is_valid_function (const std::string& fcn_name, const std::string& warn_for, bool warn)
 {
   octave_function *ans = 0;
 
@@ -160,11 +160,11 @@
 }
 
 octave_function *
-is_valid_function (const octave_value& arg, const string& warn_for, bool warn)
+is_valid_function (const octave_value& arg, const std::string& warn_for, bool warn)
 {
   octave_function *ans = 0;
 
-  string fcn_name;
+  std::string fcn_name;
 
   if (arg.is_string ())
     fcn_name = arg.string_value ();
@@ -178,9 +178,9 @@
 }
 
 octave_function *
-extract_function (const octave_value& arg, const string& warn_for,
-		  const string& fname, const string& header,
-		  const string& trailer)
+extract_function (const octave_value& arg, const std::string& warn_for,
+		  const std::string& fname, const std::string& header,
+		  const std::string& trailer)
 {
   octave_function *retval = 0;
 
@@ -188,9 +188,9 @@
 
   if (! retval)
     {
-      string s = arg.string_value ();
+      std::string s = arg.string_value ();
 
-      string cmd = header;
+      std::string cmd = header;
       cmd.append (s);
       cmd.append (trailer);
 
@@ -224,7 +224,7 @@
 }
 
 string_vector
-get_struct_elts (const string& text)
+get_struct_elts (const std::string& text)
 {
   int n = 1;
 
@@ -261,13 +261,13 @@
 }
 
 string_vector
-generate_struct_completions (const string& text, string& prefix, string& hint)
+generate_struct_completions (const std::string& text, std::string& prefix, std::string& hint)
 {
   string_vector names;
 
   size_t pos = text.rfind ('.');
 
-  string id;
+  std::string id;
   string_vector elts;
 
   if (pos == NPOS)
@@ -324,13 +324,13 @@
 }
 
 bool
-looks_like_struct (const string& text)
+looks_like_struct (const std::string& text)
 {
   bool retval = true;
 
   string_vector elts = get_struct_elts (text);
 
-  string id = elts[0];
+  std::string id = elts[0];
 
   symbol_record *sr = curr_sym_tab->lookup (id);
 
@@ -391,11 +391,11 @@
       return retval;
     }
 
-  string name = args(0).string_value ();
+  std::string name = args(0).string_value ();
 
   if (error_state)
     {
-      error ("is_global: expecting string argument");
+      error ("is_global: expecting std::string argument");
       return retval;
     }
 
@@ -430,16 +430,16 @@
       return retval;
     }
 
-  string name = args(0).string_value ();
+  std::string name = args(0).string_value ();
 
   if (error_state)
     {
-      error ("exist: expecting string argument");
+      error ("exist: expecting std::string argument");
       return retval;
     }
 
-  string struct_elts;
-  string symbol_name = name;
+  std::string struct_elts;
+  std::string symbol_name = name;
 
   size_t pos = name.find ('.');
 
@@ -475,7 +475,7 @@
     }
   else
     {
-      string path = fcn_file_in_path (name);
+      std::string path = fcn_file_in_path (name);
 
       if (path.length () > 0)
 	{
@@ -491,7 +491,7 @@
 	    }
 	  else
 	    {
-	      string file_name = file_in_path (name, "");
+	      std::string file_name = file_in_path (name, "");
 
 	      if (! file_name.empty ())
 		{
@@ -523,7 +523,7 @@
 
       if (tmp)
 	{
-	  string ff = tmp->fcn_file_name ();
+	  std::string ff = tmp->fcn_file_name ();
 
 	  if (! (ff.empty ()
 		 || (Vignore_function_time_stamp
@@ -533,7 +533,7 @@
 		{
 		  time_t tp = tmp->time_parsed ();
 
-		  string fname;
+		  std::string fname;
 
 		  if (tmp->is_dld_function ())
 		    fname = ff;
@@ -587,7 +587,7 @@
 // current symbol table.
 
 symbol_record *
-lookup_by_name (const string& nm, bool exec_script)
+lookup_by_name (const std::string& nm, bool exec_script)
 {
   symbol_record *sym_rec = curr_sym_tab->lookup (nm, true);
 
@@ -597,7 +597,7 @@
 }
 
 octave_value
-get_global_value (const string& nm)
+get_global_value (const std::string& nm)
 {
   octave_value retval;
 
@@ -619,7 +619,7 @@
 }
 
 void
-set_global_value (const string& nm, const octave_value& val)
+set_global_value (const std::string& nm, const octave_value& val)
 {
   symbol_record *sr = global_sym_tab->lookup (nm, true);
 
@@ -634,8 +634,8 @@
 // Look for the given name in the global symbol table.  If it refers
 // to a string, return a new copy.  If not, return 0;
 
-string
-builtin_string_variable (const string& name)
+std::string
+builtin_string_variable (const std::string& name)
 {
   symbol_record *sr = global_sym_tab->lookup (name);
 
@@ -643,7 +643,7 @@
 
   assert (sr);
 
-  string retval;
+  std::string retval;
 
   octave_value val = sr->def ();
 
@@ -658,7 +658,7 @@
 // return 0.
 
 int
-builtin_real_scalar_variable (const string& name, double& d)
+builtin_real_scalar_variable (const std::string& name, double& d)
 {
   int status = 0;
   symbol_record *sr = global_sym_tab->lookup (name);
@@ -681,7 +681,7 @@
 // Look for the given name in the global symbol table.
 
 octave_value
-builtin_any_variable (const string& name)
+builtin_any_variable (const std::string& name)
 {
   symbol_record *sr = global_sym_tab->lookup (name);
 
@@ -707,7 +707,7 @@
 
       if (! error_state)
 	{
-	  string nm = sr->name ();
+	  std::string nm = sr->name ();
 
 	  symbol_record *gsr = global_sym_tab->lookup (nm, true);
 
@@ -756,7 +756,7 @@
 // given name defined in the global symbol table.
 
 void
-force_link_to_function (const string& id_name)
+force_link_to_function (const std::string& id_name)
 {
   symbol_record *gsr = global_sym_tab->lookup (id_name, true);
   if (gsr->is_function ())
@@ -779,11 +779,11 @@
 
   if (nargin == 2)
     {
-      string name = args(0).string_value ();
+      std::string name = args(0).string_value ();
 
       if (! error_state)
 	{
-	  string help = args(1).string_value ();
+	  std::string help = args(1).string_value ();
 
 	  if (! error_state)
 	    {
@@ -820,7 +820,7 @@
   bool show_variables = false;
   bool show_verbose = false;
 
-  string my_name = argv[0];
+  std::string my_name = argv[0];
 
   int i;
   for (i = 1; i < argc; i++)
@@ -1014,13 +1014,13 @@
 // functions needed?
 
 void
-bind_builtin_constant (const string& name, const octave_value& val,
-		       bool protect, bool eternal, const string& help)
+bind_builtin_constant (const std::string& name, const octave_value& val,
+		       bool protect, bool eternal, const std::string& help)
 {
   symbol_record *sym_rec = global_sym_tab->lookup (name, true);
   sym_rec->unprotect ();
 
-  string tmp_help = help.empty () ? sym_rec->help () : help;
+  std::string tmp_help = help.empty () ? sym_rec->help () : help;
 
   sym_rec->define_builtin_const (val);
 
@@ -1040,10 +1040,10 @@
 // functions needed?
 
 void
-bind_builtin_variable (const string& varname, const octave_value& val,
+bind_builtin_variable (const std::string& varname, const octave_value& val,
 		       bool protect, bool eternal,
 		       symbol_record::change_function chg_fcn,
-		       const string& help)
+		       const std::string& help)
 {
   symbol_record *sr = global_sym_tab->lookup (varname, true);
 
@@ -1179,7 +1179,7 @@
 
       for (int k = idx; k < argc; k++)
 	{
-	  string patstr = argv[k];
+	  std::string patstr = argv[k];
 
 	  if (! patstr.empty ())
 	    {
@@ -1189,7 +1189,7 @@
 
 	      for (int i = 0; i < lcount; i++)
 		{
-		  string nm = lvars[i];
+		  std::string nm = lvars[i];
 		  int match = pattern.match (nm);
 		  if ((exclusive && ! match) || (! exclusive && match))
 		    curr_sym_tab->clear (nm);
@@ -1198,7 +1198,7 @@
 	      int gcount = gvars.length ();
 	      for (int i = 0; i < gcount; i++)
 		{
-		  string nm = gvars[i];
+		  std::string nm = gvars[i];
 		  int match = pattern.match (nm);
 		  if ((exclusive && ! match) || (! exclusive && match))
 		    {
@@ -1211,7 +1211,7 @@
 	      int fcount = fcns.length ();
 	      for (int i = 0; i < fcount; i++)
 		{
-		  string nm = fcns[i];
+		  std::string nm = fcns[i];
 		  int match = pattern.match (nm);
 		  if ((exclusive && ! match) || (! exclusive && match))
 		    {
@@ -1238,7 +1238,7 @@
 
   if (nargin == 1)
     {
-      string arg = args(0).string_value ();
+      std::string arg = args(0).string_value ();
 
       if (arg == "global")
 	global_sym_tab->print_stats ();
@@ -1265,7 +1265,7 @@
 
   if (nargin == 1)
     {
-      string symbol_name = args(0).string_value ();
+      std::string symbol_name = args(0).string_value ();
 
       if (! error_state)
 	{
@@ -1294,7 +1294,7 @@
 {
   int pref = 0;
 
-  string val = builtin_string_variable ("ignore_function_time_stamp");
+  std::string val = builtin_string_variable ("ignore_function_time_stamp");
 
   if (! val.empty ())
     {
diff --git a/src/variables.h b/src/variables.h
--- a/src/variables.h
+++ b/src/variables.h
@@ -43,52 +43,52 @@
 
 extern void initialize_symbol_tables (void);
 
-extern bool is_builtin_variable (const string&);
-extern bool is_text_function_name (const string&);
-extern bool is_mapper_function_name (const string&);
-extern bool is_builtin_function_name (const string&);
-extern bool is_globally_visible (const string&);
+extern bool is_builtin_variable (const std::string&);
+extern bool is_text_function_name (const std::string&);
+extern bool is_mapper_function_name (const std::string&);
+extern bool is_builtin_function_name (const std::string&);
+extern bool is_globally_visible (const std::string&);
 
 extern octave_function *
-is_valid_function (const octave_value&, const string& = string (),
+is_valid_function (const octave_value&, const std::string& = std::string (),
 		   bool warn = false); 
 
 extern octave_function *
-is_valid_function (const string&, const string& = string (),
+is_valid_function (const std::string&, const std::string& = std::string (),
 		   bool warn = false); 
 
 extern octave_function *
-extract_function (const octave_value& arg, const string& warn_for,
-		  const string& fname, const string& header,
-		  const string& trailer);
+extract_function (const octave_value& arg, const std::string& warn_for,
+		  const std::string& fname, const std::string& header,
+		  const std::string& trailer);
 
 extern string_vector
-get_struct_elts (const string& text);
+get_struct_elts (const std::string& text);
 
 extern string_vector
-generate_struct_completions (const string& text, string& prefix,
-			     string& hint);
+generate_struct_completions (const std::string& text, std::string& prefix,
+			     std::string& hint);
 
 extern bool
-looks_like_struct (const string& text);
+looks_like_struct (const std::string& text);
 
 extern bool lookup (symbol_record *s, bool exec_script = true);
 
 extern symbol_record *
-lookup_by_name (const string& nm, bool exec_script = true);
+lookup_by_name (const std::string& nm, bool exec_script = true);
 
-extern octave_value get_global_value (const string& nm);
+extern octave_value get_global_value (const std::string& nm);
 
-extern void set_global_value (const string& nm, const octave_value& val);
+extern void set_global_value (const std::string& nm, const octave_value& val);
 
-extern string builtin_string_variable (const string&);
-extern int builtin_real_scalar_variable (const string&, double&);
-extern octave_value builtin_any_variable (const string&);
+extern std::string builtin_string_variable (const std::string&);
+extern int builtin_real_scalar_variable (const std::string&, double&);
+extern octave_value builtin_any_variable (const std::string&);
 
 extern void link_to_global_variable (symbol_record *sr);
 extern void link_to_builtin_or_function (symbol_record *sr);
 
-extern void force_link_to_function (const string&);
+extern void force_link_to_function (const std::string&);
 
 extern void bind_ans (const octave_value& val, bool print);
 
@@ -97,15 +97,15 @@
 extern void clear_global_error_variable (void *);
 
 extern void
-bind_builtin_constant (const string&, const octave_value&,
+bind_builtin_constant (const std::string&, const octave_value&,
 		       bool protect = false, bool eternal = false,
-		       const string& help = string ());
+		       const std::string& help = std::string ());
 
 extern void
-bind_builtin_variable (const string&, const octave_value&,
+bind_builtin_variable (const std::string&, const octave_value&,
 		       bool protect = false, bool eternal = false,
 		       symbol_record::change_function f = 0,
-		       const string& help = string ());
+		       const std::string& help = std::string ());
 
 // Symbol table for symbols at the top level.
 extern symbol_table *top_level_sym_tab;