Code shared from the Rust Playground

playground.rs

#![allow(dead_code)]
use std::cell::RefCell;

#[derive(Debug)]
struct Ctx {
    mult: i32,
    items: RefCell<Vec<i32>>,
}

fn work(x: &Ctx, i: &mut i32) {
    *i = *i * x.mult;
}

fn simplework(x: &i32, i: &mut i32) {
    *i = *i * x;
}

fn proc(x: &Ctx) {
    let mut items = x.items.borrow_mut();
    for item in items.iter_mut() {
        //work(x, item);
        simplework(&x.mult, item);
    }
}

fn main() {
    let x = Ctx{mult: 100,
                    items: RefCell::new(vec!(1, 2, 3))};

    proc(&x);
    println!("{:?}", x);
}