singleton with std::call_once

include/Singleton_call_once.hpp

@@ -0,0 +1,41 @@
+#ifndef SINGLETON_CALL_ONCE_HPP
+#define SINGLETON_CALL_ONCE_HPP
+
+#include <mutex>
+
+template<typename T>
+class Singleton_call_once
+{
+protected:
+
+    Singleton_call_once() {};
+    virtual ~Singleton_call_once() {};
+
+private:
+
+    Singleton_call_once( const Singleton_call_once& );
+    Singleton_call_once& operator=( const Singleton_call_once& );
+
+public:
+
+    static T* getInstance()
+    {
+      std::call_once(m_flag, &Singleton_call_once::do_init);
+      return m_instance;
+    }
+
+private:
+
+    static void do_init()
+    {
+        m_instance = new T();
+    }
+
+    static T* m_instance;
+    static std::once_flag m_flag;
+};
+
+template<class T> T* Singleton_call_once<T>::m_instance = 0;
+template<class T> std::once_flag Singleton_call_once<T>::m_flag;
+
+#endif // SINGLETON_CALL_ONCE_HPP

test/CMakeLists.txt

@@ -16,7 +16,7 @@ if(CXXTEST_FOUND)
   generated_main.cpp
   Fixture.hpp
 
-  test_Multiton.hpp
+  test_Singelton_call_once.hpp
 #    test_Singleton.hpp
 #    test_Singleton_meyers.hpp
 #    test_Singleton_DCLP.hpp

test/test_Singelton_call_once.hpp

@@ -0,0 +1,35 @@
+#include <cxxtest/TestSuite.h>
+
+#define private public // need to reach Singleton's private m_instance
+
+#include "Common.hpp"
+#include "Fixture.hpp"
+#include "Singleton_call_once.hpp"
+
+
+class TestSingletonCallOnceSuite : public CxxTest::TestSuite
+{
+
+private:
+
+  class BasicSingleton : public Singleton_call_once<BasicSingleton>
+  {
+    public:
+      int getSeven()
+      {
+        TRACE;
+        return 7;
+      }
+  };
+
+public:
+
+  void testBasic( void )
+  {
+    TEST_HEADER;
+
+    TS_ASSERT_EQUALS( BasicSingleton::getInstance()->getSeven(), 7 );
+  }
+
+
+};