Examples with ? operator not working?

[Siilwyn]

Hi there, I'm new to Rust so this might not be related to reqwest. As far as I understand the ? operator can only be used inside functions that return a Result. However in the examples this isn't mentioned. Simply running the first example:

let text = reqwest::get("https://www.rust-lang.org")?
    .text()?;

println!("body = {:?}", body);

Returns cannot use the ? operator in a function that returns () and body not found in this scope. Then changing the code to:

let text = reqwest::get("https://www.rust-lang.org")
    .text();

println!("text = {:?}", text);

Returns no method named text found for type std::result::Result<reqwest::Response, reqwest::Error>, any help appreciated.

[messense]

try:

extern crate reqwest;

fn foo() -> Result<(), reqwest::Error> {
    let text = reqwest::get("https://www.rust-lang.org")?
        .text()?;
    
    println!("body = {:?}", text);
    Ok(())
}

fn main() {
    foo().unwrap();
}

[Siilwyn]

Thanks @messense that works & confirms my guess that it only works within a function returning a Result. Do you think it's a good idea to simplify the example so it works anywhere in main? For me it caused some confusion.

[seanmonstar]

The examples were changed to show using ? because the community as a whole wanted to move away from showing examples where errors just cause crashes (by unwraping all errors). Eventually (seems like about a couple months), it'll be possible to return an error from the main function, and so examples can be update to that!

In the meantime, this might be helpful: have the very first example show using in fn main and an auxiliary fn run, simply calling run().unwrap() in main. Then, have a note after the example that all other examples assume a similar setup. What do you think of that?

[Siilwyn]

I dug into this a bit and indeed found it is the recommended way to write examples. I'm fond of copy and pasting snippets to try but I can see how this provides a cleaner way of showing functionality. Guess most people won't get as confused as I was about the ? unless they're completely new to Rust like me.

Will create a PR!

[sassman]

seems that even without a function is now supported.

extern crate reqwest;

fn main() -> reqwest::Result<()> {
    let body = reqwest::get("https://www.rust-lang.org")?.text()?;

    println!("{}", body);

    Ok(())
}

tested on rustc 1.33.0 (2aa4c46cf 2019-02-28)

[cetanu]

None of the above examples work on Rust 1.40.......

[Vaxure1337]

None of the above examples work on Rust 1.40.......

same here

[MichaelARoberts]

Confirmed. It does not work on 1.4.3 either.

[palahacker]

same problem here.