Hyper::client and https, how?

tl;dr What is TLS implementation in the context of hyper::client?

I have read https://hyper.rs/guides/client/basic/
In the example code it has:

    // HTTPS requires picking a TLS implementation, so give a better
    // warning if the user tries to request an 'https' URL.
    let url = url.parse::<hyper::Uri>().unwrap();
    if url.scheme_part().map(|s| s.as_ref()) != Some("http") {
        println!("This example only works with 'http' URLs.");

This is not useful to me. What does picking a TLS implementation mean?
There is not a lot of http these days!
So what do I do?


https://crates.io/crates/hyper-tls and https://crates.io/crates/hyper-openssl are two commonly used implementations.


Thank you, I think I can make that work.