| use core::iter::*; | |
| #[test] | |
| fn test_map_try_folds() { | |
| let f = &|acc, x| i32::checked_add(2 * acc, x); | |
| assert_eq!((0..10).map(|x| x + 3).try_fold(7, f), (3..13).try_fold(7, f)); | |
| assert_eq!((0..10).map(|x| x + 3).try_rfold(7, f), (3..13).try_rfold(7, f)); | |
| let mut iter = (0..40).map(|x| x + 10); | |
| assert_eq!(iter.try_fold(0, i8::checked_add), None); | |
| assert_eq!(iter.next(), Some(20)); | |
| assert_eq!(iter.try_rfold(0, i8::checked_add), None); | |
| assert_eq!(iter.next_back(), Some(46)); | |
| } | |
| #[test] | |
| fn test_double_ended_map() { | |
| let xs = [1, 2, 3, 4, 5, 6]; | |
| let mut it = xs.iter().map(|&x| x * -1); | |
| assert_eq!(it.next(), Some(-1)); | |
| assert_eq!(it.next(), Some(-2)); | |
| assert_eq!(it.next_back(), Some(-6)); | |
| assert_eq!(it.next_back(), Some(-5)); | |
| assert_eq!(it.next(), Some(-3)); | |
| assert_eq!(it.next_back(), Some(-4)); | |
| assert_eq!(it.next(), None); | |
| } |