whatalnk

use std::collections::HashMap;
use std::collections::hash_map::Entry;

fn main() {
    let mut d = HashMap::new();
    match d.entry("k1") {
        Entry::Vacant(e) => {
            e.insert(Vec::new());
        }
        Entry::Occupied(mut e) => {

whatalnk

use std::collections::HashMap;

fn make_freq_table<'a>(
    data: &'a [u16],
    counter: HashMap<&'a u16, usize>,
) -> HashMap<&'a u16, usize> {
    let mut c = counter;
    for x in data {
        let entry = c.entry(x).or_insert(0);
        *entry += 1;