Index: include/std/ratio
===================================================================
--- include/std/ratio	(revision 189214)
+++ include/std/ratio	(working copy)
@@ -1,6 +1,6 @@
 // ratio -*- C++ -*-
 
-// Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright (C) 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the 
@@ -282,9 +282,8 @@
   template<intmax_t _Num, intmax_t _Den>
     constexpr intmax_t ratio<_Num, _Den>::den;
 
-  /// ratio_multiply
   template<typename _R1, typename _R2>
-    struct ratio_multiply
+    struct __ratio_multiply
     {
     private:
       static const intmax_t __gcd1 =
@@ -304,18 +303,21 @@
     };
 
   template<typename _R1, typename _R2>
-    constexpr intmax_t ratio_multiply<_R1, _R2>::num;
+    constexpr intmax_t __ratio_multiply<_R1, _R2>::num;
 
   template<typename _R1, typename _R2>
-    constexpr intmax_t ratio_multiply<_R1, _R2>::den;
+    constexpr intmax_t __ratio_multiply<_R1, _R2>::den;
 
-  /// ratio_divide
+  /// ratio_multiply
   template<typename _R1, typename _R2>
-    struct ratio_divide
+    using ratio_multiply = typename __ratio_multiply<_R1, _R2>::type;
+
+  template<typename _R1, typename _R2>
+    struct __ratio_divide
     {
       static_assert(_R2::num != 0, "division by 0");
 
-      typedef typename ratio_multiply<
+      typedef typename __ratio_multiply<
         _R1,
         ratio<_R2::den, _R2::num>>::type type;
 
@@ -324,11 +326,15 @@
     };
 
   template<typename _R1, typename _R2>
-    constexpr intmax_t ratio_divide<_R1, _R2>::num;
+    constexpr intmax_t __ratio_divide<_R1, _R2>::num;
 
   template<typename _R1, typename _R2>
-    constexpr intmax_t ratio_divide<_R1, _R2>::den;
+    constexpr intmax_t __ratio_divide<_R1, _R2>::den;
 
+  /// ratio_divide
+  template<typename _R1, typename _R2>
+    using ratio_divide = typename __ratio_divide<_R1, _R2>::type;
+
   /// ratio_equal
   template<typename _R1, typename _R2>
     struct ratio_equal
@@ -464,9 +470,8 @@
       typedef ratio<__n_final::__quot_lo, __d_final::__lo> type;
     };
 
-  /// ratio_add
   template<typename _R1, typename _R2>
-    struct ratio_add
+    struct __ratio_add
     {
       typedef typename __ratio_add_impl<_R1, _R2>::type type;
       static constexpr intmax_t num = type::num;
@@ -474,16 +479,19 @@
     };
 
   template<typename _R1, typename _R2>
-    constexpr intmax_t ratio_add<_R1, _R2>::num;
+    constexpr intmax_t __ratio_add<_R1, _R2>::num;
 
   template<typename _R1, typename _R2>
-    constexpr intmax_t ratio_add<_R1, _R2>::den;
+    constexpr intmax_t __ratio_add<_R1, _R2>::den;
 
-  /// ratio_subtract
+  /// ratio_add
   template<typename _R1, typename _R2>
-    struct ratio_subtract
+    using ratio_add = typename __ratio_add<_R1, _R2>::type;
+
+  template<typename _R1, typename _R2>
+    struct __ratio_subtract
     {
-      typedef typename ratio_add<
+      typedef typename __ratio_add<
         _R1,
         ratio<-_R2::num, _R2::den>>::type type;
 
@@ -492,11 +500,14 @@
     };
 
   template<typename _R1, typename _R2>
-    constexpr intmax_t ratio_subtract<_R1, _R2>::num;
+    constexpr intmax_t __ratio_subtract<_R1, _R2>::num;
 
   template<typename _R1, typename _R2>
-    constexpr intmax_t ratio_subtract<_R1, _R2>::den;
+    constexpr intmax_t __ratio_subtract<_R1, _R2>::den;
 
+  /// ratio_subtract
+  template<typename _R1, typename _R2>
+    using ratio_subtract = typename __ratio_subtract<_R1, _R2>::type;
 
 
   typedef ratio<1,       1000000000000000000> atto;
Index: include/std/chrono
===================================================================
--- include/std/chrono	(revision 189214)
+++ include/std/chrono	(working copy)
@@ -1,6 +1,6 @@
 // <chrono> -*- C++ -*-
 
-// Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright (C) 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -174,8 +174,7 @@
       {
 	typedef typename _ToDur::period				__to_period;
 	typedef typename _ToDur::rep				__to_rep;
-	typedef ratio_divide<_Period, __to_period> 		__r_div;
-	typedef typename __r_div::type 				__cf;
+	typedef ratio_divide<_Period, __to_period> 		__cf;
 	typedef typename common_type<__to_rep, _Rep, intmax_t>::type
 	  							__cr;
 	typedef  __duration_cast_impl<_ToDur, __cf, __cr,
@@ -242,7 +241,7 @@
 
 	template<typename _Rep2, typename _Period2, typename = typename
 	       enable_if<treat_as_floating_point<rep>::value
-			 || (ratio_divide<_Period2, period>::type::den == 1
+			 || (ratio_divide<_Period2, period>::den == 1
 			     && !treat_as_floating_point<_Rep2>::value)>::type>
 	  constexpr duration(const duration<_Rep2, _Period2>& __d)
 	  : __r(duration_cast<duration>(__d).count()) { }
Index: testsuite/20_util/duration/requirements/typedefs_neg1.cc
===================================================================
--- testsuite/20_util/duration/requirements/typedefs_neg1.cc	(revision 189214)
+++ testsuite/20_util/duration/requirements/typedefs_neg1.cc	(working copy)
@@ -3,7 +3,7 @@
 // { dg-require-cstdint "" }
 // 2008-07-31 Chris Fairles <chris.fairles@gmail.com>
 
-// Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright (C) 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -31,5 +31,5 @@
   test_type d;
 }
 
-// { dg-error "rep cannot be a duration" "" { target *-*-* } 226 }
+// { dg-error "rep cannot be a duration" "" { target *-*-* } 225 }
 // { dg-error "required from here" "" { target *-*-* } 31 }
Index: testsuite/20_util/duration/requirements/typedefs_neg2.cc
===================================================================
--- testsuite/20_util/duration/requirements/typedefs_neg2.cc	(revision 189214)
+++ testsuite/20_util/duration/requirements/typedefs_neg2.cc	(working copy)
@@ -3,7 +3,7 @@
 // { dg-require-cstdint "" }
 // 2008-07-31 Chris Fairles <chris.fairles@gmail.com>
 
-// Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
+// Copyright (C) 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -32,5 +32,5 @@
   test_type d;			// { dg-error "required from here" }
 }
 
-// { dg-error "must be a specialization of ratio" "" { target *-*-* } 227 }
+// { dg-error "must be a specialization of ratio" "" { target *-*-* } 226 }
 // { dg-prune-output "not a member" }
Index: testsuite/20_util/duration/requirements/typedefs_neg3.cc
===================================================================
--- testsuite/20_util/duration/requirements/typedefs_neg3.cc	(revision 189214)
+++ testsuite/20_util/duration/requirements/typedefs_neg3.cc	(working copy)
@@ -3,7 +3,7 @@
 // { dg-require-cstdint "" }
 // 2008-07-31 Chris Fairles <chris.fairles@gmail.com>
 
-// Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright (C) 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -33,5 +33,5 @@
   test_type d;
 }
 
-// { dg-error "period must be positive" "" { target *-*-* } 229 }
+// { dg-error "period must be positive" "" { target *-*-* } 228 }
 // { dg-error "required from here" "" { target *-*-* } 33 }
Index: testsuite/20_util/ratio/operations/ops_overflow_neg.cc
===================================================================
--- testsuite/20_util/ratio/operations/ops_overflow_neg.cc	(revision 189214)
+++ testsuite/20_util/ratio/operations/ops_overflow_neg.cc	(working copy)
@@ -4,7 +4,7 @@
 
 // 2008-07-03 Chris Fairles <chris.fairles@gmail.com>
 
-// Copyright (C) 2008, 2009, 2011 Free Software Foundation
+// Copyright (C) 2008, 2009, 2011, 2012 Free Software Foundation
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -40,9 +40,9 @@
 }
 
 // { dg-error "required from here" "" { target *-*-* } 29 }
-// { dg-error "required from here" "" { target *-*-* } 36 }
-// { dg-error "required from here" "" { target *-*-* } 38 }
-// { dg-error "overflow in addition" "" { target *-*-* } 429 }
+// { dg-error "expected initializer" "" { target *-*-* } 36 }
+// { dg-error "expected initializer" "" { target *-*-* } 38 }
+// { dg-error "overflow in addition" "" { target *-*-* } 435 }
 // { dg-error "overflow in multiplication" "" { target *-*-* } 97 }
 // { dg-error "overflow in multiplication" "" { target *-*-* } 99 }
 // { dg-error "overflow in multiplication" "" { target *-*-* } 101 }
Index: testsuite/20_util/ratio/operations/53840.cc
===================================================================
--- testsuite/20_util/ratio/operations/53840.cc	(revision 0)
+++ testsuite/20_util/ratio/operations/53840.cc	(revision 0)
@@ -0,0 +1,27 @@
+// { dg-options "-std=gnu++0x" }
+// { dg-require-cstdint "" }
+// { dg-do compile }
+
+// Copyright (C) 2012 Free Software Foundation
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <chrono>
+
+std::chrono::duration<long, std::ratio_divide<std::kilo, std::milli>>   d1;
+std::chrono::duration<long, std::ratio_multiply<std::kilo, std::milli>> d2;
+std::chrono::duration<long, std::ratio_add<std::kilo, std::milli>>      d3;
+std::chrono::duration<long, std::ratio_subtract<std::kilo, std::milli>> d4;
