Added thread safe singleton class

include/util/threadsafesingleton.h

@@ -0,0 +1,39 @@
+/*
+ * threadsafesingleton.h
+ *
+ *  Created on: Aug 7, 2015
+ *      Author: f4exb
+ */
+
+#ifndef INCLUDE_UTIL_THREADSAFESINGLETON_H_
+#define INCLUDE_UTIL_THREADSAFESINGLETON_H_
+
+//! Template class used to make from a class a singleton.
+/** S is the type of the singleton object to instantiate.
+    <br> This class permits to gather all singleton code in the same place
+    and not to pollute object interface with singleton methods.
+    <br> Accessing to the instance of S is made through ThreadSafeSingleton<S>::instance()
+    <br><B>Note :</B> The class using this adapter should have constructor and
+    destructor protected and copy constructor and operator= private.
+    <br>Besides it should declare the class ThreadSafeSingleton<S> friend in order
+    this class can make the construction.
+*/
+
+template <class S> class ThreadSafeSingleton
+{
+public:
+    static S& instance() { return *_pInstance; }
+
+protected:
+    ThreadSafeSingleton() {}
+    ~ThreadSafeSingleton() { delete _pInstance; }
+    static S* _pInstance;
+
+private:
+    ThreadSafeSingleton(const ThreadSafeSingleton&) {}
+    ThreadSafeSingleton& operator = (const ThreadSafeSingleton&) {return *this;}
+};
+
+template <class S> S *ThreadSafeSingleton<S>::_pInstance = new S;
+
+#endif /* INCLUDE_UTIL_THREADSAFESINGLETON_H_ */