A wrapper around existing iterators to extend them with backtracking functionality by providing an in-memory history.
In order to create a backtracking iterator on top of an existing iterator, you first wrap it in a BacktrackingRecord
. From there, you have two choices of BacktrackingIterator
:
* Copying
, which produces memory clones of the iterator items
* Referencing
, which produces immutable borrows on iterator items
The behaviour comes from the BacktrackingIterator
trait.
use backtracking_iterator::{BacktrackingIterator, BacktrackingRecord};
let mut backtracking_record = BacktrackingRecord::new(my_iter);
let mut my_backtracking_iter = backtracking_record.copying();
// Now we can call `next()`, and the result will also be copied
let here = my_backtracking_iter.get_ref_point();
let fresh = my_backtracking_iter.next();
my_backtracking_iter.backtrack(here);
let remembered = my_backtracking_iter.next();
assert!(fresh == remembered);