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]);