repeat in core::iter - Rust
Description: Creates a new iterator that endlessly repeats a single element.

# Function repeat

1.6.0 · Source

    pub fn repeat<T: Clone>(elt: T) -> Repeat<T> ⓘ

Expand description

Creates a new iterator that endlessly repeats a single element.

The `repeat()` function repeats a single value over and over again.

Infinite iterators like `repeat()` are often used with adapters like `Iterator::take()`, in order to make them finite.

Use `str::repeat()` instead of this function if you just want to repeat a char/string `n`th times.

If the element type of the iterator you need does not implement `Clone`, or if you do not want to keep the repeated element in memory, you can instead use the `repeat_with()` function.

## §Examples

Basic usage:

    use std::iter;

    // the number four 4ever:
    let mut fours = iter::repeat(4);

    assert_eq!(Some(4), fours.next());
    assert_eq!(Some(4), fours.next());
    assert_eq!(Some(4), fours.next());
    assert_eq!(Some(4), fours.next());
    assert_eq!(Some(4), fours.next());

    // yup, still four
    assert_eq!(Some(4), fours.next());

Going finite with `Iterator::take()`:

    use std::iter;

    // that last example was too many fours. Let's only have four fours.
    let mut four_fours = iter::repeat(4).take(4);

    assert_eq!(Some(4), four_fours.next());
    assert_eq!(Some(4), four_fours.next());
    assert_eq!(Some(4), four_fours.next());
    assert_eq!(Some(4), four_fours.next());

    // ... and now we're done
    assert_eq!(None, four_fours.next());