This is similar to fold(), but instead of returning the final accumulated result, it returns an iterator that yields the current accumulated value for each iteration. In other words, the last element yielded by accumulate() is what would have been returned by fold() if it was used instead.

Example

use iter_accumulate::IterAccumulate;

let input = [1, 2, 3, 4, 5];
let mut iter = input.iter().accumulate(1, |acc, i| acc * i);

assert_eq!(iter.next(), Some(1));
assert_eq!(iter.next(), Some(2));
assert_eq!(iter.next(), Some(6));
assert_eq!(iter.next(), Some(24));
assert_eq!(iter.next(), Some(120));
assert_eq!(iter.next(), None);