Reused vec in loop

[nerditation]

add this line after vec.clear():

    vec.clear();
+   vec = vec.into_iter().map(|_| unreachable!()).collect();

UPDATE:

since this was selected as the answer, you can read previous threads on the same topic for detailed explanation, such as:

Cleared Vec still holding onto borrow

The following code won't compile as I'm assigning to s which is borrowed by v. I understand that this would invalidate the reference, however because I've drained v before the assignment, there should be no references left to invalidate. Is there something I'm missing here? fn main() { let mut v: Vec<&str> = Vec::new(); let mut s = String::from("Foo"); v.push(&s); v.drain(..).for_each(|s| println!("{s}")); s = String::from("Bar"); v.push(&s); } I can workaroun…

Pattern: how to reuse a `Vec<&str>` across loop iterations?

In a previous question an answer was partially found: Review of unsafe usage. I've reduced the problem a bit more and really feel like there is a pattern for doing this that I'm missing. I don't want to re-allocate the vec each loop. The answer in the link above is good, but really constrains things like propagating errors and storing the cache on a struct etc. Is there a simpler way? use std::{ error::Error, io::{BufRead, BufReader}, }; use regex::Regex; const DATA: &[u8] = b" This…