Function tracing_core::stdlib::iter::repeat
1.0.0 · source · pub fn repeat<T>(elt: T) -> Repeat<T> ⓘwhere
T: Clone,
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());