Function std::iter::repeat
[−]
[src]
pub fn repeat<T>(elt: T) -> Repeat<T> where T: Clone
1.0.0Creates a new iterator that endlessly repeats a single element.
The repeat()
function repeats a single value over and over and over and
over and over and 🔁.
Infinite iterators like repeat()
are often used with adapters like
take()
, in order to make them finite.
Examples
Basic usage:
fn main() { 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()); }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 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());