From aa14800121bd1aa4dc2be57cf05af34bb1abdf60 Mon Sep 17 00:00:00 2001
From: "Peter D. Barnes, Jr." <barnes26@llnl.gov>
Date: Tue, 21 Jul 2015 16:21:49 -0700
Subject: [PATCH] Add NonCopyable, refactor Singleton.

---
 src/core/model/non-copyable.h | 75 +++++++++++++++++++++++++++++++++++
 src/core/model/singleton.h    | 27 ++-----------
 src/core/wscript              |  1 +
 3 files changed, 80 insertions(+), 23 deletions(-)
 create mode 100644 src/core/model/non-copyable.h

diff --git a/src/core/model/non-copyable.h b/src/core/model/non-copyable.h
new file mode 100644
index 000000000..e4eb19aa6
--- /dev/null
+++ b/src/core/model/non-copyable.h
@@ -0,0 +1,75 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2015 Lawrence Livermore National Laboratory
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program 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 program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author:  Peter D. Barnes, Jr. <pdbarnes@llnl.gov>
+ */
+
+#ifndef NS3_NON_COPYABLE_H
+#define NS3_NON_COPYABLE_H
+
+/**
+ * \file
+ * \ingroup access
+ * ns3::NonCopyable class declaration and implementation.
+ */
+
+/**
+ * \ingroup core
+ * \defgroup access NonCopyable and Singleton
+ * Helpers to make classes non-copyable or singleton.
+ */
+
+namespace ns3 {
+
+/**
+ * \ingroup access
+ * A base class for (non-Singleton) objects which shouldn't be copied.
+ *
+ * To prevent copying of your `class ExampleNC` just inherit from NonCopyable:
+ * \code
+ *   class ExampleNC : private NonCopyable { ... };
+ * \endcode
+ *
+ * This class prevents each instance of a derived class from being copied.
+ * If you want only a single global instance of the derived class,
+ * see Singleton.
+ *
+ * \internal
+ * This is based on `boost::noncopyable`.
+ */
+class NonCopyable
+{
+protected:
+  /** Constructor. */
+  NonCopyable () {}
+  /** Destructor. */
+  ~NonCopyable () {}
+
+private:
+  /** Copy constructor.  Private, so not copyable. */
+  NonCopyable (const NonCopyable &);
+  /**
+   * Assignment.  Private, so not copyable.
+   * \param [in] other The dummy argument
+   * \return The unmodified copy.
+   */
+  NonCopyable & operator = (const NonCopyable &other);
+}; 
+
+} // namespace ns3 
+
+#endif /* NS3_NON_COPYABLE_H */
diff --git a/src/core/model/singleton.h b/src/core/model/singleton.h
index b80688884..8983da847 100644
--- a/src/core/model/singleton.h
+++ b/src/core/model/singleton.h
@@ -20,6 +20,9 @@
 #ifndef SINGLETON_H
 #define SINGLETON_H
 
+#include "non-copyable.h"
+
+
 /**
  * \file
  * \ingroup access
@@ -57,7 +60,7 @@ namespace ns3 {
  * finalizer.
  */
 template <typename T>
-class Singleton
+class Singleton : private NonCopyable
 {
 public:
   /**
@@ -70,28 +73,6 @@ public:
    */
   static T *Get (void);
 
-private:
-
-  /**
-   * \name %Singleton pattern
-   * Private constructor, copy and assignment operator.
-   *
-   *  Note these do not have to be implemented, since they are
-   *  never called.
-   */
-  /**@{*/
-  /** Default constructor */
-  Singleton<T> (void);
-  
-  /** Copy constructor. */
-  Singleton<T> (const Singleton<T> &);
-  /**
-   * Assignment.
-   * \returns The Singleton.
-   */
-  Singleton<T> operator = (const Singleton<T> &);
-  /**@}*/
-
 };
 
 } // namespace ns3
diff --git a/src/core/wscript b/src/core/wscript
index 87b9169c8..6f13716e6 100644
--- a/src/core/wscript
+++ b/src/core/wscript
@@ -296,6 +296,7 @@ def build(bld):
         'model/hash-fnv.h',
         'model/hash.h',
         'model/valgrind.h',
+        'model/non-copyable.h',
         ]
 
     if sys.platform == 'win32':