--- a/src/core/global-value.cc	Mon Apr 14 16:19:17 2008 -0700
+++ b/src/core/global-value.cc	Thu Apr 17 13:42:25 2008 -0700
@@ -25,11 +25,11 @@
 namespace ns3 {
 
 GlobalValue::GlobalValue (std::string name, std::string help,
-			  Attribute initialValue,
+			  const AttributeValue &initialValue,
 			  Ptr<const AttributeChecker> checker)
   : m_name (name),
     m_help (help),
-    m_initialValue (initialValue),
+    m_initialValue (initialValue.Copy ()),
     m_checker (checker)
 {
   if (m_checker == 0)
@@ -49,10 +49,20 @@
 {
   return m_help;
 }
-Attribute 
-GlobalValue::GetValue (void) const
+void
+GlobalValue::GetValue (AttributeValue &value) const
 {
-  return m_initialValue;
+  bool ok = m_checker->Copy (*m_initialValue, value);
+  if (ok)
+    {
+      return;
+    }
+  StringValue *str = dynamic_cast<StringValue *> (&value);
+  if (str == 0)
+    {
+      NS_FATAL_ERROR ("GlobalValue name="<<m_name<<": input value is not a string");
+    }
+  str->Set (m_initialValue->SerializeToString (m_checker));
 }
 Ptr<const AttributeChecker> 
 GlobalValue::GetChecker (void) const
@@ -61,37 +71,37 @@
 }
   
 bool
-GlobalValue::SetValue (Attribute value)
+GlobalValue::SetValue (const AttributeValue &value)
 {
   if (m_checker->Check (value))
     {
-      m_initialValue = value;
+      m_initialValue = value.Copy ();
       return true;
     }
   // attempt to convert to string.
-  const StringValue *str = value.DynCast<const StringValue *> ();
+  const StringValue *str = dynamic_cast<const StringValue *> (&value);
   if (str == 0)
     {
       return false;
     }
   // attempt to convert back to value.
-  Attribute v = m_checker->Create ();
-  bool ok = v.DeserializeFromString (str->Get ().Get (), m_checker);
+  Ptr<AttributeValue> v = m_checker->Create ();
+  bool ok = v->DeserializeFromString (str->Get (), m_checker);
   if (!ok)
     {
       return false;
     }
-  ok = m_checker->Check (v);
+  ok = m_checker->Check (*v);
   if (!ok)
     {
       return false;
     }
-  m_initialValue = v;
+  m_checker->Copy (*v, *PeekPointer (m_initialValue));
   return true;
 }
 
 void 
-GlobalValue::Bind (std::string name, Attribute value)
+GlobalValue::Bind (std::string name, const AttributeValue &value)
 {
   for (Iterator i = Begin (); i != End (); i++)
     {
@@ -107,7 +117,7 @@
   NS_FATAL_ERROR ("Non-existant global value: "<<name);
 }
 bool 
-GlobalValue::BindFailSafe (std::string name, Attribute value)
+GlobalValue::BindFailSafe (std::string name, const AttributeValue &value)
 {
   for (Iterator i = Begin (); i != End (); i++)
     {
@@ -160,11 +170,13 @@
 {
   bool result = true;
   GlobalValue uint = GlobalValue ("TestUint", "help text",
-				  Uinteger (10),
+				  UintegerValue (10),
 				  MakeUintegerChecker<uint32_t> ());
 
 
-  NS_TEST_ASSERT_EQUAL (10, Uinteger (uint.GetValue ()).Get ());
+  UintegerValue v;
+  uint.GetValue (v);
+  NS_TEST_ASSERT_EQUAL (10, v.Get ());
 
   GlobalValue::Vector *vector = GlobalValue::GetVector ();
   for (GlobalValue::Vector::iterator i = vector->begin (); i != vector->end (); ++i)