1 files changed, 65 insertions, 0 deletions
diff --git a/include/util/Singleton.hpp b/include/util/Singleton.hpp
new file mode 100755
index 0000000..1bfb460
--- /dev/null
+++ b/include/util/Singleton.hpp
@@ -0,0 +1,65 @@
+#ifndef __SINGLETON_H
+#define __SINGLETON_H
+
+#include "ScopedPtr.hpp"
+#include "NonCopyable.hpp"
+#include "Exportable.hpp"
+#include "Noreturn.hpp"
+
+#include <cstdlib>
+#include <stdexcept>
+
+#define DECLARE_SINGLETON( T ) \
+	friend class scopedPtr< T >; \
+	friend class Singleton< T >;
+
+#define DEFINE_SINGLETON( T ) \
+	SINGLETON_EXTERN template class SINGLETON_EXPORT Singleton< T >; 
+
+template< class T >
+class Singleton : private noncopyable
+{
+	public:
+		static T& instance( )
+		{
+			if( destroyed ) {
+				onDeadReference( );
+			}
+			
+			if( t == 0 ) {
+				create( );
+			}
+			
+			return *t;
+		}
+	
+	protected:
+		Singleton( )
+		{
+		}
+		
+		virtual ~Singleton( )
+		{
+			destroyed = true;
+		}
+				
+	private:
+		static void create( )
+		{
+			t.reset( new T );
+		}
+		
+		static void onDeadReference( ) CRAWLER_NORETURN
+		{
+			throw std::runtime_error( "singleton has already been destroyed!" );
+		}
+	
+		static scopedPtr<T> t;
+		static bool destroyed;
+};
+
+template< class T > scopedPtr<T> Singleton<T>::t( 0 );
+template< class T > bool Singleton<T>::destroyed( false );
+
+#endif
+