slice::contains is not general in the key like HashMap::get

I tried this code:

fn main() {
    let words = ["hello", "world"].map(|s| s.to_string());

    // this works fine
    let hm: std::collections::HashMap<String, usize> = words
        .iter()
        .cloned()
        .zip(words.iter().map(|w| w.len()))
        .collect();
    assert_eq!(hm.get("hello"), Some(&5));

    // this does NOT work
    assert!(words.contains("hello"));
    // but has this simple workaround
    assert!(words.iter().any(|e| e == "hello"));
}

I expected to see this happen: works

Instead, this happened: slice::contains does not accept a &str instead of a &String, like HashMap::get does. I tried searching for older issues to see if there may be a good reason for this, but I did not find anything.

Start with the slice::contains and HashMap::get entry points, using the reproducer in the issue to compare their accepted key types. Determine the intended generalization for slices and verify that the &str lookup works without breaking existing contains calls.