@@ -44,10 +44,26 @@
 #endif
 
 #ifndef __has_feature
 # define __has_feature(x) 0
 #endif
+
+#if defined(__clang__)
+# define OF_HAVE_PROPERTIES
+# define OF_HAVE_OPTIONAL_PROTOCOLS
+# define OF_HAVE_FAST_ENUMERATION
+#elif defined(__GNUC__)
+# if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+#  define OF_HAVE_PROPERTIES
+#  define OF_HAVE_OPTIONAL_PROTOCOLS
+#  define OF_HAVE_FAST_ENUMERATION
+# endif
+#endif
+
+#if __has_feature(blocks)
+# define OF_HAVE_BLOCKS
+#endif
 
 #if __has_feature(objc_bool)
 # undef YES
 # define YES __objc_yes
 # undef NO