/* Free directly after use if non-NULL. Will never contain an underscore
* (so clients can safely use that as a separator). */
char *grid_new_desc(grid_type type, int width, int height, random_state *rs);
-char *grid_validate_desc(grid_type type, int width, int height, char *desc);
+char *grid_validate_desc(grid_type type, int width, int height,
+ const char *desc);
-grid *grid_new(grid_type type, int width, int height, char *desc);
+grid *grid_new(grid_type type, int width, int height, const char *desc);
void grid_free(grid *g);