Add override patch by hende, to check for proper deriving in the class tree....

Add override patch by hende, to check for proper deriving in the class tree. Added MSVC support for this feature, should work beginning with MSVC 2010

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4539 dfc29bdd-3216-0410-991c-e03cc46cb475

include/irrTypes.h

@@ -195,6 +195,20 @@ For functions:		template<class T> _IRR_DEPRECATED_ void test4(void) {}
 #define _IRR_DEPRECATED_
 #endif
 
+//! Defines an override macro, to protect virtual functions from typos and other mismatches
+/** Usage in a derived class:
+virtual void somefunc() _IRR_OVERRIDE_;
+*/
+#if (__GNUC__ >= 4 && __GNUC_MINOR__ >= 7)
+#define _IRR_OVERRIDE_ override
+#elif (_MSC_VER >= 1600 ) /* supported since MSVC 2010 */
+#define _IRR_OVERRIDE_ override
+#elif (__clang_major__ >= 3)
+#define _IRR_OVERRIDE_ override
+#else
+#define _IRR_OVERRIDE_
+#endif
+
 //! Defines a small statement to work around a microsoft compiler bug.
 /** The microsoft compiler 7.0 - 7.1 has a bug:
 When you call unmanaged code that returns a bool type value of false from managed code,