+#define USHORT_SIZE (sizeof (unsigned short))
+#define UINT_SIZE (sizeof (unsigned int))
+
+/* Return how many bytes one unit (char, short, or int) in FORMAT
+ occupies. */
+
+#define UNIT_BYTES(format) \
+ ((format) <= MTEXT_FORMAT_UTF_8 ? 1 \
+ : (format) <= MTEXT_FORMAT_UTF_16BE ? USHORT_SIZE \
+ : UINT_SIZE)
+