Struct Iter

pub struct Iter<'a, T> { /* private fields */ }

Iterates over all permutations of a slice.

The permutations are iterated in value order:

let mut iter = Iter::new(&mut xs);
let mut i = 0;
while let Some(xs) = iter.next() {
    assert_eq!(encode(xs), i);
    i += 1;
}

If the iteration goes to the end (i.e. next returns None), then the slice is restored to its initial value (i.e. increasing):

let saved_xs = xs.clone();
let mut iter = Iter::new(&mut xs);
while iter.next().is_some() {}
assert_eq!(xs, saved_xs);

Examples

let mut iter = Iter::new(&mut xs);
while let Some(xs) = iter.next() {
    process(xs);
}

Implementations

impl<'a, T: Ord> Iter<'a, T>

pub fn new(xs: &mut [T]) -> Iter<'_, T>

Constructs an iterator with an increasing slice.

Panics

Panics in debug mode if xs is not increasing.

pub fn next(&mut self) -> Option<&[T]>

Returns the next permutation.

If iteration is over, returns None.