diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 744c02ce03bee796125478391bd3fdad85fd6955..f7867cb8c12b6510cf382fdbb68d1d856e638932 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2004-12-06  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/tr1/type_traits: Implement is_reference.
+	* testsuite/tr1/4_metaprogramming/primary_type_categories/
+	is_reference/is_reference.cc: New.
+	* testsuite/tr1/4_metaprogramming/primary_type_categories/
+	is_reference/typedefs.cc: Likewise.
+
 2004-12-05  Paolo Carlini  <pcarlini@suse.de>
 
 	PR libstdc++/18837
diff --git a/libstdc++-v3/include/tr1/type_traits b/libstdc++-v3/include/tr1/type_traits
index 913a2b71c818758e7a60c9c26025f28d36c9def7..44d8a4e35839f09ed56dd377726a1bd39faa3fa9 100644
--- a/libstdc++-v3/include/tr1/type_traits
+++ b/libstdc++-v3/include/tr1/type_traits
@@ -22,8 +22,8 @@
  *  This is a TR1 C++ Library header. 
  */
 
-#ifndef _TR1_TYPE_TRAITS
-#define _TR1_TYPE_TRAITS 1
+#ifndef _TYPE_TRAITS
+#define _TYPE_TRAITS 1
 
 #include <bits/c++config.h>
 #include <cstddef>
@@ -102,8 +102,13 @@ namespace tr1
   template<typename _Tp>
     struct is_pointer;
   
+  template<typename>
+    struct is_reference
+    : public false_type { };
+
   template<typename _Tp>
-    struct is_reference;
+    struct is_reference<_Tp&>
+    : public true_type { };
   
   template<typename _Tp>
     struct is_member_object_pointer;
diff --git a/libstdc++-v3/testsuite/tr1/4_metaprogramming/primary_type_categories/is_reference/is_reference.cc b/libstdc++-v3/testsuite/tr1/4_metaprogramming/primary_type_categories/is_reference/is_reference.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2442edb3b0505c3f37f0d40ab58c58f73f81d1f2
--- /dev/null
+++ b/libstdc++-v3/testsuite/tr1/4_metaprogramming/primary_type_categories/is_reference/is_reference.cc
@@ -0,0 +1,51 @@
+// 2004-12-06  Paolo Carlini  <pcarlini@suse.de>
+//
+// Copyright (C) 2004 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 4.5.1 Primary type categories
+
+#include <tr1/type_traits>
+#include <testsuite_hooks.h>
+#include <testsuite_tr1.h>
+
+class ClassType { };
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  using std::tr1::is_reference;
+  using __gnu_test::test_category;
+
+  typedef int&           int_ref;
+  typedef ClassType&     ClassType_ref;
+  typedef int (&fun_ref) (int);
+
+  VERIFY( (test_category<is_reference, int_ref, true>()) );
+  VERIFY( (test_category<is_reference, ClassType_ref, true>()) );
+  VERIFY( (test_category<is_reference, fun_ref, true>()) );
+
+  // Sanity check.
+  VERIFY( (test_category<is_reference, ClassType, false>()) );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/tr1/4_metaprogramming/primary_type_categories/is_reference/typedefs.cc b/libstdc++-v3/testsuite/tr1/4_metaprogramming/primary_type_categories/is_reference/typedefs.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ecc197b82d6f4b74a2ad9574ec1e15fca145f378
--- /dev/null
+++ b/libstdc++-v3/testsuite/tr1/4_metaprogramming/primary_type_categories/is_reference/typedefs.cc
@@ -0,0 +1,36 @@
+// 2004-12-06  Paolo Carlini  <pcarlini@suse.de>
+//
+// Copyright (C) 2004 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 
+// NB: This file is for testing tr1/type_traits with NO OTHER INCLUDES.
+
+#include <tr1/type_traits>
+
+// { dg-do compile }
+
+void test01()
+{
+  // Check for required typedefs
+  typedef std::tr1::is_reference<int>         test_type;
+  typedef test_type::value_type               value_type;
+  typedef test_type::type                     type;
+  typedef test_type::type::value_type         type_value_type;
+  typedef test_type::type::type               type_type;
+}