Function find_duplicates 

pub fn find_duplicates<T: Clone + Eq + Hash>(items: &[T]) -> Vec<T>

Find duplicate items in a vector. Returns a vector of items that appear more than once.

Examples

use chie_shared::find_duplicates;

let numbers = vec![1, 2, 3, 2, 4, 3, 5];
let mut dupes = find_duplicates(&numbers);
dupes.sort(); // Order is not guaranteed
assert_eq!(dupes, vec![2, 3]);

// Works with strings too
let words = vec!["cat", "dog", "cat", "bird", "dog"];
let mut dup_words = find_duplicates(&words);
dup_words.sort();
assert_eq!(dup_words, vec!["cat", "dog"]);

// No duplicates returns empty vector
let unique = vec![1, 2, 3, 4];
assert_eq!(find_duplicates(&unique), Vec::<i32>::new());