+ /** Append an ID range onto an IDL.
+ * @param[in,out] idp Address of the IDL to append to.
+ * @param[in] id The lowest ID to append.
+ * @param[in] n Number of IDs to append.
+ * @return 0 on success, ENOMEM if the IDL is too large.
+ */
+int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n );
+
+ /** Merge an IDL onto an IDL. The destination IDL must be big enough.
+ * @param[in] idl The IDL to merge into.
+ * @param[in] merge The IDL to merge.
+ */
+void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge );
+