Allow Client::get(&Url)

[dbrgn]

I'm using a function that should be passed a reference to a reqwest::Url object. It should then GET that URL.

fn get_resource(url: &Url) {
    let client = Client::new();
    client.get(url);
}

Unfortunately it seems that this is not possible, because &Url does not implement reqwest::IntoUrl.

Is it really necessary that the Url object is moved into the get method?

Play: https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=48cbed79f2143a227c36ec4936a2dff8

[seanmonstar]

The situation is similar to when a function requires a String: it's usually best to ask the user for an owned String, instead of &str and clone internally, since it's probable the user had to allocate to make it in the first place, so taking &str would just result in a second copy.

Url implements Clone, so you can just create a copy to give to the request.

[dbrgn]

If the get method does require an owned Url object then the case is clear, yes 🙂 That was my question.

(If borrowing is sufficient on the other hand, adding the possibility of passing in a &Url would be great.)

[roy-work]

The situation is similar to when a function requires a String: it's usually best to ask the user for an owned String, instead of &str and clone internally, since it's probable the user had to allocate to make it in the first place, so taking &str would just result in a second copy.

First, I agree with the logic here, of taking the owned object, when the owned object is required.

But IntoUrl seems unable to decide whether it obeys that logic or not, as &str implements IntoUrl; that means that, while you can't do ::get(&Url), you can do ::get(a_url_ref.as_str()) and seemingly "get around it". But … the IntoUrl implementation then clones that &str into a Url internally. (Worse, it parses it, which I presume is a much heavier operation than an internal .clone() would be.)

(Still, I'm a bit on the fence: .get("https://a/static/string") is nice, .get("https://…".to_owned()) is a bit cumbersome.)