-# if defined(_GLIBCXX_INCLUDE_AS_TR1)
-# error C++0x header cannot be included from TR1 header
-# endif
-# if defined(_GLIBCXX_INCLUDE_AS_CXX0X)
-# include <tr1_impl/cctype>
-# else
-# define _GLIBCXX_INCLUDE_AS_CXX0X
-# define _GLIBCXX_BEGIN_NAMESPACE_TR1
-# define _GLIBCXX_END_NAMESPACE_TR1
-# define _GLIBCXX_TR1
-# include <tr1_impl/cctype>
-# undef _GLIBCXX_TR1
-# undef _GLIBCXX_END_NAMESPACE_TR1
-# undef _GLIBCXX_BEGIN_NAMESPACE_TR1
-# undef _GLIBCXX_INCLUDE_AS_CXX0X
-# endif
-#endif
+
+#ifdef _GLIBCXX_USE_C99_CTYPE_TR1
+
+#undef isblank
+
+_GLIBCXX_BEGIN_NAMESPACE(std)
+
+ using ::isblank;
+
+_GLIBCXX_END_NAMESPACE
+
+#endif // _GLIBCXX_USE_C99_CTYPE_TR1
+
+#endif // __GXX_EXPERIMENTAL_CXX0X__