How to write a Rust function that takes an iterator?

Question

I\'d like to write a function that accepts an iterator and returns the results of some operations on it. Specifically, I\'m trying to iterate over the values of a Has

Answer 1

Easiest is using an impl Trait, impl Iterator:

use std::collections::HashMap;

fn find_min<'a>(vals: impl Iterator) -> Option<&'a u32> {
    vals.min()
}

fn main() {
    let mut map = HashMap::new();
    map.insert("zero", 0u32);
    map.insert("one", 1u32);
    println!("Min value {:?}", find_min(map.values()));
}

playground