/* Value of point when current_column was called */
extern int last_known_column_point;
+
+/* Functions for dealing with the column cache. */
+
+/* Return true iff the display table DISPTAB specifies the same widths
+ for characters as WIDTHTAB. We use this to decide when to
+ invalidate the buffer's column_cache. */
+extern int disptab_matches_widthtab ( /* struct Lisp_Vector *disptab,
+ struct Lisp_Vector *widthtab */ );
+
+/* Recompute BUF's width table, using the display table DISPTAB. */
+extern void recompute_width_table ( /* struct buffer *buf,
+ struct Lisp_Vector *disptab */ );