Clippy should detect opportunities for `into_` variants

What it does

Identify places where an into_* function variant might be more efficient than cases where a non-into plus a clone is being used.

Lint Name

use_into_version

Category

style, perf

Advantage

• Removes unnecessary allocations of types by moving them
• Cleans up code

Drawbacks

No response

Example

// Note: this function receives and returns owned values
fn get_keys(hm: HashMap<String, u32>) -> Vec<String> {
    hm.keys().map(|k| k.to_string()).collect()
}

Could be written as:

fn get_keys(hm: HashMap<String, u32>) -> Vec<String> {
    hm.into_keys().collect()
}

Start by reviewing how Clippy lints are structured and how the proposed use_into_version pattern could be detected. Use the HashMap<String, u32> example as the initial case, then determine the intended broader scope. Done means the lint identifies eligible non-into calls followed by cloning and avoids inappropriate suggestions.