+
+#if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
+# define IN_CTYPE_DOMAIN(c) 1
+#else
+# define IN_CTYPE_DOMAIN(c) isascii(c)
+#endif
+
+#define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
+#define ISDIGIT(c) (IN_CTYPE_DOMAIN (c) && isdigit (c))
+#define TOLOWER(c) (IN_CTYPE_DOMAIN (c) ? tolower(c) : (c))
+