Macro itertools::izip [−][src]
macro_rules! izip {
(@ closure $p : pat => $tup : expr) => { ... };
(@ closure $p : pat => ($($tup : tt) *), $_iter : expr $(, $tail : expr) *) => { ... };
($first : expr $(,) *) => { ... };
($first : expr, $second : expr $(,) *) => { ... };
($first : expr $(, $rest : expr) * $(,) *) => { ... };
}
Expand description
Create an iterator running multiple iterators in lockstep.
The izip!
iterator yields elements until any subiterator
returns None
.
This is a version of the standard .zip()
that’s supporting more than
two iterators. The iterator element type is a tuple with one element
from each of the input iterators. Just like .zip()
, the iteration stops
when the shortest of the inputs reaches its end.
Note: The result of this macro is in the general case an iterator
composed of repeated .zip()
and a .map()
; it has an anonymous type.
The special cases of one and two arguments produce the equivalent of
$a.into_iter()
and $a.into_iter().zip($b)
respectively.
Prefer this macro izip!()
over multizip
for the performance benefits
of using the standard library .zip()
.
// iterate over three sequences side-by-side
let mut results = [0, 0, 0, 0];
let inputs = [3, 7, 9, 6];
for (r, index, input) in izip!(&mut results, 0..10, &inputs) {
*r = index * 10 + input;
}
assert_eq!(results, [0 + 3, 10 + 7, 29, 36]);