Consider tuple iteration

[brson]

Original proposed in #870, some syntax sugar for iterating over multiple things.

[tomjakubowski]

It doesn't really need to be syntax sugar. If it's done as an IntoIterator impl on tuples then it's not exactly syntax, is it?

I've written code like:

for (bx, (by, bz)) in xs.iter().zip(ys.iter().zip(zs.iter_mut())) { }

too many times. This would be much appreciated and make iterating over several iterables at once far easier to read, in my opinion.

[devyn]

I would love to see this. Zip syntax right now is kind of ugly and unreadable, IMHO. I almost prefer to use indices instead of iterators half the time. I don't think there's any reason why we couldn't have both.

[Amanieu]

See #1650 which presents one way to do this.

[devyn]

I'm not really sure I see how that would make this possible. I'm just looking for an impl of IntoIterator for the tuples where every element implements IntoIterator that behaves somewhat like zip does.

That is,

for x in (&[1, 2, 3], &[4, 5, 6]) {
    println!("{:?}", x);
}

would be equivalent to

for x in (&[1,2,3]).into_iter().zip(&[4,5,6]) {
    println!("{:?}", x);
}

[Amanieu]

Ah sorry, I misunderstood what you were asking for. What I had in mind was somelike like a map operation that you could perform on each element of a tuple, even if they have different types.

[Kixunil]

Should rust-lang/rust#43242 be part of this RFC or a separate one?