+/* --- @mptext_len@ --- *
+ *
+ * Arguments: @mp *x@ = number to work on
+ * @int r@ = radix the number will be expressed in
+ *
+ * Returns: The number of digits needed to represent the number in the
+ * given base. This will not include space for a leading sign
+ * (use @MP_ISNEG@ to check that, or just add one on for luck);
+ * neither will it add space for a terminating null. In general
+ * the answer will be an overestimate.
+ */
+
+extern size_t mptext_len(mp */*x*/, int /*r*/);
+