+ ? (t) -1 \
+ : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
+
+/* Return zero if T can be determined to be an unsigned type.
+ Otherwise, return 1.
+ When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a
+ tighter bound. Otherwise, it overestimates the true bound by one byte
+ when applied to unsigned types of size 2, 4, 16, ... bytes.
+ The symbol signed_type_or_expr__ is private to this header file. */
+# if __GNUC__ >= 2
+# define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t))
+# else
+# define signed_type_or_expr__(t) 1
+# endif