+#if USE_WIDEC_SUPPORT
+#if HAVE_MBTOWC && HAVE_MBLEN
+#define reset_mbytes(state) IGNORE_RC(mblen(NULL, 0)), IGNORE_RC(mbtowc(NULL, NULL, 0))
+#define count_mbytes(buffer,length,state) mblen(buffer,length)
+#define check_mbytes(wch,buffer,length,state) \
+ (int) mbtowc(&wch, buffer, length)
+#define state_unused
+#elif HAVE_MBRTOWC && HAVE_MBRLEN
+#define reset_mbytes(state) init_mb(state)
+#define count_mbytes(buffer,length,state) mbrlen(buffer,length,&state)
+#define check_mbytes(wch,buffer,length,state) \
+ (int) mbrtowc(&wch, buffer, length, &state)
+#else
+make an error
+#endif
+#endif /* USE_WIDEC_SUPPORT */
+