Unify HashSet contains and Vec contains solutions

playground.rs

#[allow(dead_code)]
fn contains<'a, V, T, Q>(arr: V, value: &Q) -> bool
where
    T: 'a + std::cmp::PartialEq<Q>,
    V: std::iter::IntoIterator<Item = &'a T>
{
    arr.into_iter().any(|v| v == value)
}

#[test]
fn test_contains_hash_set() {
    use std::collections::HashSet;

    let hs_str: HashSet<&str> = ["a", "b", "c"].iter().copied().collect();
    let hs_string: HashSet<String> = vec!["a".to_string(), "b".to_string(), "c".to_string()]
        .into_iter()
        .collect();

    let value_str = "b";
    let value_string = String::from(value_str);
    
    assert!(contains(&hs_str, &value_string));
    assert!(contains(&hs_string, &value_str));
    assert!(contains(&hs_string, &"a"));
}

#[test]
fn test_contains_vec() {
    let array_str = ["a", "b", "c"];
    let array_string = ["a".to_string(), "b".to_string(), "c".to_string()];

    let value_str = "b";
    let value_string = String::from(value_str);

    assert!(contains(&array_str, &value_string));
    assert!(contains(&array_string, &value_str));
    assert!(contains(&array_string, &"b"));
}