start a restructure

Creational/Singleton/Singleton.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace DesignPatterns\Singleton;
+
+/**
+ * class Singleton
+ */
+class Singleton
+{
+    /**
+     * @var cached reference to singleton instance 
+     */
+    protected static $instance;
+    
+    /**
+     * gets the instance via lazy initialization (created on first usage)
+     *
+     * @return self
+     */
+    public static function getInstance()
+    {
+        
+        if (null === static::$instance) {
+            static::$instance = new static;
+        }
+
+        return static::$instance;
+    }
+
+    /**
+     * is not allowed to call from outside: private!
+     *
+     */
+    private function __construct()
+    {
+
+    }
+
+    /**
+     * prevent the instance from being cloned
+     *
+     * @return void
+     */
+    private function __clone()
+    {
+
+    }
+
+    /**
+     * prevent from being unserialized
+     *
+     * @return void
+     */
+    private function __wakeup()
+    {
+
+    }
+}