diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index b79cee21fd0..7a41704fb81 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2004-12-12  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/tr1/type_traits: Implement extent.
+	* testsuite/tr1/4_metaprogramming/type_properties/extent/
+	extent.cc: New.
+	* testsuite/tr1/4_metaprogramming/type_properties/extent/
+	typedefs.cc: Likewise.
+
 2004-12-12  Paolo Carlini  <pcarlini@suse.de>
 
 	* include/tr1/type_traits: Implement is_pointer, remove_pointer,
diff --git a/libstdc++-v3/include/tr1/type_traits b/libstdc++-v3/include/tr1/type_traits
index 6fef185b5b3..f38f51e858d 100644
--- a/libstdc++-v3/include/tr1/type_traits
+++ b/libstdc++-v3/include/tr1/type_traits
@@ -244,8 +244,21 @@ namespace tr1
     struct rank<_Tp[]>
     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
    
-  template<typename _Tp, unsigned _Uint = 0>
-    struct extent;
+  template<typename, unsigned = 0>
+    struct extent
+    : integral_constant<std::size_t, 0> { };
+  
+  template<typename _Tp, unsigned _Uint, std::size_t _Size>
+    struct extent<_Tp[_Size], _Uint>
+    : integral_constant<std::size_t,
+			_Uint == 0 ? _Size : extent<_Tp, _Uint - 1>::value>
+    { };
+
+  template<typename _Tp, unsigned _Uint>
+    struct extent<_Tp[], _Uint>
+    : integral_constant<std::size_t,
+			_Uint == 0 ? 0 : extent<_Tp, _Uint - 1>::value>
+    { };
   
   /// @brief  relationships between types [4.6].
   template<typename, typename>
diff --git a/libstdc++-v3/testsuite/tr1/4_metaprogramming/type_properties/extent/extent.cc b/libstdc++-v3/testsuite/tr1/4_metaprogramming/type_properties/extent/extent.cc
new file mode 100644
index 00000000000..a5891aa059a
--- /dev/null
+++ b/libstdc++-v3/testsuite/tr1/4_metaprogramming/type_properties/extent/extent.cc
@@ -0,0 +1,57 @@
+// 2004-12-12  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.
+
+// 4.5.3 Type properties
+
+#include <tr1/type_traits>
+#include <testsuite_hooks.h>
+#include <testsuite_tr1.h>
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  using std::tr1::extent;
+  using namespace __gnu_test;
+
+  VERIFY( (test_property<extent, int>(0)) );
+  VERIFY( (test_property<extent, int[2]>(2)) );
+  VERIFY( (test_property<extent, int[2][4]>(2)) );
+  VERIFY( (test_property<extent, int[][4]>(0)) );
+  VERIFY( (extent<int, 1>::value == 0) );
+  VERIFY( (extent<int[2], 1>::value == 0) );
+  VERIFY( (extent<int[2][4], 1>::value == 4) );
+  VERIFY( (extent<int[][4], 1>::value == 4) );
+  VERIFY( (extent<int[10][4][6][8][12][2], 4>::value == 12) );
+  VERIFY( (test_property<extent, ClassType>(0)) );
+  VERIFY( (test_property<extent, ClassType[2]>(2)) );
+  VERIFY( (test_property<extent, ClassType[2][4]>(2)) );
+  VERIFY( (test_property<extent, ClassType[][4]>(0)) );
+  VERIFY( (extent<ClassType, 1>::value == 0) );
+  VERIFY( (extent<ClassType[2], 1>::value == 0) );
+  VERIFY( (extent<ClassType[2][4], 1>::value == 4) );
+  VERIFY( (extent<ClassType[][4], 1>::value == 4) );
+  VERIFY( (extent<ClassType[10][4][6][8][12][2], 4>::value == 12) );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/tr1/4_metaprogramming/type_properties/extent/typedefs.cc b/libstdc++-v3/testsuite/tr1/4_metaprogramming/type_properties/extent/typedefs.cc
new file mode 100644
index 00000000000..02a468c5821
--- /dev/null
+++ b/libstdc++-v3/testsuite/tr1/4_metaprogramming/type_properties/extent/typedefs.cc
@@ -0,0 +1,36 @@
+// 2004-12-11  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::extent<int, 1>            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;
+}