-Byte *memrchr (Byte const * p, int n, char c);
-Byte *strrev (Byte* byte_l, int length_i);
+/* namespace std { */
+
+#if ! HAVE_SNPRINTF /* GNU extension. */
+int snprintf (char *str, size_t n, char const *format, ...);
+ __attribute__ ((format (printf, 3, 4)));
+#endif
+
+#if ! HAVE_VSNPRINTF /* GNU extension. */
+int vsnprintf (char *str, size_t, char const *format, va_list args);
+#endif
+
+#ifndef isinf
+#if ! HAVE_ISINF /* BSD extension. */
+int isinf (double x);
+#endif
+#endif