--- a/src/core/object.cc	Fri Feb 08 02:22:36 2008 +0100
+++ b/src/core/object.cc	Fri Feb 08 04:11:08 2008 +0100
@@ -643,21 +643,6 @@
   bool ok = DoSet (info.spec, value);
   return ok;
 }
-bool 
-Parameters::Set (std::string name, std::string value)
-{
-  struct TypeId::ParameterInfo info;
-  TypeId::LookupParameterByFullName (name, &info);
-  bool ok = DoSet (info.spec,value);
-  return ok;
-}
-void 
-Parameters::SetWithTid (TypeId tid, std::string name, std::string value)
-{
-  struct TypeId::ParameterInfo info;
-  tid.LookupParameterByName (name, &info);
-  DoSet (info.spec, value);
-}
 void 
 Parameters::SetWithTid (TypeId tid, std::string name, PValue value)
 {
@@ -666,13 +651,6 @@
   DoSet (info.spec, value);
 }
 void 
-Parameters::SetWithTid (TypeId tid, uint32_t position, std::string value)
-{
-  struct TypeId::ParameterInfo info;
-  tid.LookupParameterByPosition (position, &info);
-  DoSet (info.spec, value);
-}
-void 
 Parameters::SetWithTid (TypeId tid, uint32_t position, PValue value)
 {
   struct TypeId::ParameterInfo info;
@@ -709,32 +687,16 @@
   bool ok = spec->Check (value);
   if (!ok)
     {
-      return false;
+      PValue v = spec->CreateValue ();
+      ok = v.ConvertFrom (value, spec);
+      if (!ok)
+        {
+          return false;
+        }
     }
   DoSetOne (spec, value);
   return true;
 }
-bool
-Parameters::DoSet (Ptr<const ParamSpec> spec, std::string value)
-{
-  if (spec == 0)
-    {
-      return false;
-    }
-  PValue v = spec->CreateValue ();
-  bool ok = v.DeserializeFromString (value, spec);
-  if (!ok)
-    {
-      return false;
-    }
-  ok = spec->Check (v);
-  if (!ok)
-    {
-      return false;
-    }
-  DoSetOne (spec, v);
-  return true;
-}
 void 
 Parameters::Reset (void)
 {
@@ -894,7 +856,7 @@
             if (j->spec == paramSpec)
               {
                 // We have a matching parameter value.
-                paramSpec->Set (this, j->value);
+                DoSet (paramSpec, j->value);
                 NS_LOG_DEBUG ("construct \""<< tid.GetName ()<<"::"<<
                               tid.GetParameterName (i)<<"\"");
                 found = true;
@@ -910,7 +872,7 @@
                 if (j->spec == paramSpec)
                   {
                     // We have a matching parameter value.
-                    paramSpec->Set (this, j->value);
+                    DoSet (paramSpec, j->value);
                     NS_LOG_DEBUG ("construct \""<< tid.GetName ()<<"::"<<
                                   tid.GetParameterName (i)<<"\" from global");
                     found = true;
@@ -932,6 +894,28 @@
   NotifyConstructionCompleted ();
 }
 bool
+Object::DoSet (Ptr<const ParamSpec> spec, PValue value)
+{
+  bool ok = spec->Check (value);
+  if (!ok)
+    {
+      PValue v = spec->CreateValue ();
+      ok = v.ConvertFrom (value, spec);
+      if (!ok)
+        {
+          return false;
+        }
+      value = v;
+      ok = spec->Check (value);
+      if (!ok)
+        {
+          return false;
+        }
+    }
+  ok = spec->Set (this, value);
+  return ok;
+}
+bool
 Object::Set (std::string name, PValue value)
 {
   struct TypeId::ParameterInfo info;
@@ -943,39 +927,7 @@
     {
       return false;
     }
-  bool ok = info.spec->Check (value);
-  if (!ok)
-    {
-      return false;
-    }
-  ok = info.spec->Set (this, value);
-  return ok;
-}
-bool
-Object::Set (std::string name, std::string value)
-{
-  struct TypeId::ParameterInfo info;
-  if (!m_tid.LookupParameterByName (name, &info))
-    {
-      return false;
-    }
-  if (!(info.flags & TypeId::PARAM_SET))
-    {
-      return false;
-    }
-  PValue v = info.spec->CreateValue ();
-  bool ok = v.DeserializeFromString (value, info.spec);
-  if (!ok)
-    {
-      return false;
-    }
-  ok = info.spec->Check (v);
-  if (!ok)
-    {
-      return false;
-    }
-  ok = info.spec->Set (this, v);
-  return ok;
+  return DoSet (info.spec, value);
 }
 bool 
 Object::Get (std::string name, std::string &value) const

--- a/src/core/object.h	Fri Feb 08 02:22:36 2008 +0100
+++ b/src/core/object.h	Fri Feb 08 04:11:08 2008 +0100
@@ -294,12 +294,9 @@
    * value of that parameter. If any of these checks fails,
    * the program terminates with a message.
    */
-  bool Set (std::string name, std::string value);
   bool Set (std::string name, PValue value);
 
-  void SetWithTid (TypeId tid, std::string name, std::string value);
   void SetWithTid (TypeId tid, std::string name, PValue value);
-  void SetWithTid (TypeId tid, uint32_t position, std::string value);
   void SetWithTid (TypeId tid, uint32_t position, PValue value);
 
   /**
@@ -334,7 +331,6 @@
 
 
   bool DoSet (Ptr<const ParamSpec> spec, PValue param);
-  bool DoSet (Ptr<const ParamSpec> spec, std::string value);
   void DoSetOne (Ptr<const ParamSpec> spec, PValue param);
   std::string LookupParameterFullNameByParamSpec (Ptr<const ParamSpec> spec) const;
 
@@ -360,7 +356,6 @@
    *
    * Set a single parameter.
    */
-  bool Set (std::string name, std::string value);
   bool Set (std::string name, PValue value);
   /**
    * \param name the name of the parameter to read
@@ -475,6 +470,7 @@
   friend Ptr<T> CreateObject (T1 a1, T2 a2, T3 a3, T4 a4, T5 a5, T6 a6, T7 a7);
 
 
+  bool DoSet (Ptr<const ParamSpec> spec, PValue value);
   Ptr<Object> DoQueryInterface (TypeId tid) const;
   void DoCollectSources (std::string path, const TraceContext &context, 
                          TraceResolver::SourceCollection *collection) const;
@@ -746,18 +742,6 @@
   return CreateObject<T> (parameters);
 }
 
-template <typename T>
-Ptr<T> 
-CreateObjectWith (std::string n1, std::string v1,
-                  std::string n2 = "", std::string v2 = "")
-              
-{
-  Parameters parameters;
-  parameters.SetWithTid (T::GetTypeId (), n1, v1);
-  parameters.SetWithTid (T::GetTypeId (), n2, v2);
-  return CreateObject<T> (parameters);
-}
-
 } // namespace ns3
 
 #endif /* OBJECT_H */

--- a/src/core/value.cc	Fri Feb 08 02:22:36 2008 +0100
+++ b/src/core/value.cc	Fri Feb 08 04:11:08 2008 +0100
@@ -1,5 +1,6 @@
 #include "value.h"
 #include "log.h"
+#include "fatal-error.h"
 #include <sstream>
 
 NS_LOG_COMPONENT_DEFINE ("Value");
@@ -19,6 +20,11 @@
 }
 Value::~Value ()
 {}
+bool 
+Value::ConvertFrom (PValue value, Ptr<const ParamSpec> spec)
+{
+  return false;
+}
 
 PValue::PValue ()
   : m_value (0)
@@ -90,6 +96,24 @@
 {
   return m_value->DeserializeFromString (value, spec);
 }
+bool 
+PValue::ConvertFrom (PValue value, Ptr<const ParamSpec> spec)
+{
+  const StringValue *str = value.DynCast<const StringValue *> ();
+  if (str == 0)
+    {
+      return false;
+    }
+  return DeserializeFromString (str->Get (), spec);
+}
+
+PValue::PValue (const char *value)
+  : m_value (new StringValue (value))
+{}
+PValue::PValue (std::string value)
+  : m_value (new StringValue (value))
+{}
+
 
 ParamSpec::ParamSpec ()
   : m_count (1)
@@ -111,6 +135,54 @@
 ParamSpec::~ParamSpec ()
 {}
 
+
+StringValue::StringValue (const char *value)
+  : m_value (value)
+{}
+StringValue::StringValue (std::string value)
+  : m_value (value)
+{}
+void 
+StringValue::Set (std::string value)
+{
+  m_value = value;
+}
+std::string 
+StringValue::Get (void) const
+{
+  return m_value;
+}
+PValue 
+StringValue::Copy (void) const
+{
+  return PValue::Create<StringValue> (*this);
+}
+std::string 
+StringValue::SerializeToString (Ptr<const ParamSpec> spec) const
+{
+  return m_value;
+}
+bool 
+StringValue::DeserializeFromString (std::string value, Ptr<const ParamSpec> spec)
+{
+  m_value = value;
+  return true;
+}
+StringValue::StringValue (PValue value)
+{
+  const StringValue *v = value.DynCast<const StringValue *> ();
+  if (v == 0)
+    {
+      NS_FATAL_ERROR ("Expected value of type String.");
+    }
+  m_value = v->Get ();
+}
+StringValue::operator PValue () const
+{
+  return PValue::Create<StringValue> (*this);
+}
+
+
 std::string 
 PtrValueBase::SerializeToString (Ptr<const ParamSpec> spec) const
 {

--- a/src/core/value.h	Fri Feb 08 02:22:36 2008 +0100
+++ b/src/core/value.h	Fri Feb 08 04:11:08 2008 +0100
@@ -22,6 +22,7 @@
   virtual PValue Copy (void) const = 0;
   virtual std::string SerializeToString (Ptr<const ParamSpec> spec) const = 0;
   virtual bool DeserializeFromString (std::string value, Ptr<const ParamSpec> spec) = 0;
+  virtual bool ConvertFrom (PValue value, Ptr<const ParamSpec> spec);
 private:
   friend class PValue;
   uint32_t m_count;
@@ -38,6 +39,7 @@
   PValue Copy (void) const;
   std::string SerializeToString (Ptr<const ParamSpec> spec) const;
   bool DeserializeFromString (std::string value, Ptr<const ParamSpec> spec);
+  bool ConvertFrom (PValue value, Ptr<const ParamSpec> spec);
 
   template <typename T>
   static PValue Create (void);
@@ -52,6 +54,8 @@
   template <typename T>
   operator Ptr<T> ();
 
+  PValue (const char *value);
+  PValue (std::string value);
 private:
   PValue (Value *value);
   Value *m_value;
@@ -98,6 +102,29 @@
 namespace ns3 {
 
 /********************************************************
+ *   A class used to hold std::string values.
+ ********************************************************/
+
+class StringValue : public Value
+{
+public:
+  StringValue (const char *value);
+  StringValue (std::string value);
+  void Set (std::string value);
+  std::string Get (void) const;
+
+  virtual PValue Copy (void) const;
+  virtual std::string SerializeToString (Ptr<const ParamSpec> spec) const;
+  virtual bool DeserializeFromString (std::string value, Ptr<const ParamSpec> spec);
+
+  StringValue (PValue value);
+  operator PValue () const;
+private:
+  std::string m_value;
+};
+
+
+/********************************************************
  *   The class used to access the pointer stored in a
  *   PtrValue<T> Value instance.
  ********************************************************/