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Function std::iter::repeat
pub fn repeat<T>(elt: T) -> Repeat<T> ⓘ
where
T: Clone,
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.
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());
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/iter/fn.repeat.html