Closures and Iterators

Your learning sequence

1. 1 Not solved yet.○ Closures 101: build a pipeline of boxed closures Practice · Easy
2. 2 Not solved yet.○ Fn, FnMut, FnOnce: the closure hierarchy Practice · Medium
3. 3 Not solved yet.○ move: when the closure must own its captures Practice · Medium
4. 4 Disjoint field capture: what changed in edition 2021 Read
5. 5 Not solved yet.○ iter, iter_mut, into_iter: all three, one Vec Practice · Easy
6. 6 Not solved yet.○ Sum collections and iterators with IntoIterator Practice · Medium
7. 7 Not solved yet.○ Filter borrowed values into owned results Practice · Medium
8. 8 Not solved yet.○ Trace a lazy map, filter and take pipeline Practice · Easy
9. 9 Not solved yet.○ map, filter, filter_map: parse host:port lines Practice · Easy
10. 10 Not solved yet.○ fold and try_fold: a total that refuses to overflow Practice · Medium
11. 11 Not solved yet.○ Split a message at its first blank line Practice · Easy
12. 12 Not solved yet.○ zip and enumerate: pair two lists and report the leftovers Practice · Easy
13. 13 Not solved yet.○ peekable and next_if: write a tokeniser Practice · Hard
14. 14 Not solved yet.○ flat_map: expand a range spec like "1-3,7,10-12" Practice · Medium
15. 15 Not solved yet.○ scan: a running balance that stops at the floor Practice · Medium
16. 16 Not solved yet.○ Implement Iterator by hand: the Collatz sequence Practice · Medium
17. 17 Not solved yet.○ from_fn and successors: iterators without writing a struct Practice · Easy
18. 18 Not solved yet.○ any, all, find, position: audit a list of records Practice · Easy
19. 19 Not solved yet.○ Choose the first minimum and last maximum Practice · Medium
20. 20 Not solved yet.○ partition and unzip: split rows and group names Practice · Medium
21. 21 Not solved yet.○ collect and the turbofish: three targets, one source Practice · Medium
22. 22 Not solved yet.○ size_hint and DoubleEndedIterator: an iterator with two ends Practice · Hard
23. 23 Not solved yet.○ Write your own adapters, with an extension trait Practice · Hard
24. 24 Not solved yet.○ Make your own collection iterable, all three ways Practice · Hard
25. 25 When collect() is a mistake Read
26. 26 Not solved yet.○ Chains versus loops: top-k, and a function that must not allocate Practice · Medium
27. 27 Not solved yet.○ Read a log after its closure finishes Practice · Medium
28. 28 How iterator consumers shape a loop Read

fn main() {
    let s = String::from("owned");
    let length = move || s.len();
    println!("{} {}", length(), length());
}