iterator - Is there an owned version of String::chars?

Question

The following code does not compile:

use std::str::Chars;

struct Chunks {
    remaining: Chars,
}

impl Chunks {
    fn new(s: String) -> Self {
        Chunks {
            remaining: s.chars(),
        }
    }
}

The error is:

error[E0106]: missing lifetime specifier
 --> src/main.rs:4:16
  |
4 |     remaining: Chars,
  |                ^^^^^ expected lifetime parameter

Chars doesn't own the characters it iterates over and it can't outlive the &str or String it was created from.

Is there an owned version of Chars that does not need a lifetime parameter or do I have to keep a Vec<char> and an index myself?

Answer 1

std::vec::IntoIter is an owned version of every iterator, in a sense.

use std::vec::IntoIter;

struct Chunks {
    remaining: IntoIter<char>,
}

impl Chunks {
    fn new(s: String) -> Self {
        Chunks {
            remaining: s.chars().collect::<Vec<_>>().into_iter(),
        }
    }
}

Playground link

Downside is additional allocation and a space overhead, but I am not aware of the iterator for your specific case.