Index: trunk/nv/type_traits.hh
===================================================================
--- trunk/nv/type_traits.hh	(revision 196)
+++ trunk/nv/type_traits.hh	(revision 196)
@@ -0,0 +1,41 @@
+// Copyright (C) 2012-2013 ChaosForge / Kornel Kisielewicz
+// http://chaosforge.org/
+//
+// This file is part of NV Libraries.
+// For conditions of distribution and use, see copyright notice in nv.hh
+/**
+ * @file type_traits.hh
+ * @author Kornel Kisielewicz epyon@chaosforge.org
+ * @brief type traits
+ */
+
+#ifndef NV_TYPE_TRAITS_HH
+#define NV_TYPE_TRAITS_HH
+
+#include <nv/common.hh>
+#include <type_traits>
+
+namespace nv
+{
+#if NV_COMPILER == NV_MSVC
+	using std::underlying_type;
+#elif NV_COMPILER == NV_CLANG
+	template < typename T >
+	struct underlying_type
+	{
+		typedef __underlying_type(T) type;
+	};
+#else
+	template< typename T >
+	struct underlying_type
+	{
+		typedef typename std::conditional<
+			T( -1 ) < T( 0 ),
+			typename std::make_signed< T >::type,
+			typename std::make_unsigned< T >::type
+			>::type type;
+	};
+#endif
+}
+
+#endif // NV_TYPE_TRAITS_HH