Remove `.copied()` or `.cloned()` when possible

What it does

Currently, cloned_instead_of_copied lint suggests to replace cloned() with copied() in these examples:

pub fn lengths(items: &[&str]) -> usize {
    items.iter().cloned().map(|one| one.len() + 1).sum()
}

// both key and value are simple copiable enums
pub fn getter(key: Key, vals: &HashMap::<Key, Value>) {
    if let Some(Value::X) = vals.get(&key).cloned() {
        println!("Found X");
    }
}

but Rust allows .cloned() to be fully removed. A lint should suggest that instead of suggesting copied. I am not certain if this should be an extension to cloned_instead_of_copied or if its a new lint.

Advantage

• Shorter, possibly faster code

Drawbacks

No response

Example 1

#[must_use]
pub fn lengths(items: &[&str]) -> usize {
    items.iter().cloned().map(|one| one.len() + 1).sum()
}

fn main() {
    println!("Sum={}", lengths(&["hello", "world"]));
}

Could be written as:

pub fn lengths(items: &[&str]) -> usize {
    items.iter().map(|one| one.len() + 1).sum()
}

Example 2

use std::collections::HashMap;

#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
pub enum Key{ A, B, C }

#[derive(Clone, Copy, Debug)]
pub enum Value{ X, Y, Z }

fn main() {
    let vals = HashMap::<Key, Value>::new();
    getter(Key::A, &vals);
}

pub fn getter(key: Key, vals: &HashMap::<Key, Value>) {
    if let Some(Value::X) = vals.get(&key).cloned() {
        println!("Found X");
    }
}

Could be written as:

pub fn getter(key: Key, vals: &HashMap::<Key, Value>) {
    if let Some(Value::X) = vals.get(&key) {
        println!("Found X");
    }
}

Start by locating the cloned_instead_of_copied lint implementation and its tests, then compare how the two examples are handled. Done means the appropriate lint suggests removing .cloned() where the borrowed value can be matched or mapped directly, rather than suggesting .copied().