I32 hv_iterinit (HV* tb)
-Note that hv_iterinit I<currently> returns the number of I<buckets> in
-the hash and I<not> the number of keys (as indicated in the Advanced
-Perl Programming book). This may change in future. Use the HvKEYS(hv)
-macro to find the number of keys in a hash.
+Returns the number of keys in the hash (i.e. the same as C<HvKEYS(tb)>).
+The return value is currently only meaningful for hashes without tie
+magic.
+
+NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number
+of hash buckets that happen to be in use. If you still need that
+esoteric value, you can get it through the macro C<HvFILL(tb)>.
=item hv_iterkey