CODEWITHSUNDEEP
typesrustiterator
wonce
wonce

Reputation: 1921

What are the right data types to make a function that copies between iterators in Rust as versatile as possible?

I commonly need to copy data between two iterables. Apart from the special case of slices, I found no suitable function in the standard library, so I tried writing my own one:

fn copy(source: /* ? */, target: /* ? */) {
    for (s, t) in source.zip(target) {
        *t = s.clone();
    }
}

What would be the right choice of data types to make this function as versatile as possible?

Upvotes: 1

Views: 101

Answers (1)

Masklinn
Masklinn

Reputation: 42492

s.clone()

that doesn't seem super useful as it limits you to clonable input items. The caller can just use cloned() or copied() to adapt the iterator.

The only really necessary constraint should be that you can assign source items to target items.

I guess it'd look something like

fn copy<S, SI, T, TI>(source: S, target: T)
where
    S: Iterator<Item = SI>,
    T: Iterator<Item = TI>,
    TI: DerefMut<Target = SI>,
{
    for (s, mut t) in source.zip(target) {
        *t = s;
    }
}

but frankly for the rare cases I need to do such a thing I'd rather just write the imperative loop.

Upvotes: 5

Related Questions