Index: doc/doxygen/user.cfg.in
===================================================================
--- doc/doxygen/user.cfg.in	(revision 154736)
+++ doc/doxygen/user.cfg.in	(working copy)
@@ -1449,6 +1449,7 @@ PREDEFINED             = __cplusplus \
                          _GLIBCXX_ATOMIC_BUILTINS_8 \
                          _GLIBCXX_USE_SCHED_YIELD \
                          _GLIBCXX_USE_NANOSLEEP \
+                         __GXX_RTTI \
                          __glibcxx_function_requires=// \
                          __glibcxx_class_requires=// \
                          __glibcxx_class_requires2=// \