How can I pull data out of an Option for independent use?

Question

Is there a way to 'pull' data out of an Option? I have an API call that returns Some(HashMap). I want to use the HashMap as if it weren't inside Some and play with the data.

Based on what I've read, it looks like Some(...) is only good for match comparisons and some built-in functions.

Simple API call pulled from crate docs:

use std::collections::HashMap;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let resp = reqwest::blocking::get("https://httpbin.org/ip")?
        .json::<HashMap<String, String>>()?;
    println!("{:#?}", resp.get("origin"));
    Ok(())
}

Result:

Some("75.69.138.107")

Answer 1

if let Some(origin) = resp.get("origin") {
    // use origin
}

If you can guarantee that it's impossible for the value to be None, then you can use:

let origin = resp.get("origin").unwrap();

Or:

let origin = resp.get("origin").expect("This shouldn't be possible!");

And, since your function returns a Result:

let origin = resp.get("origin").ok_or("This shouldn't be possible!")?;

Or with a custom error type:

let origin = resp.get("origin").ok_or(MyError::DoesntExist)?;

Answer 2

Your options are a plenty.

if let Some(origin) = resp.get("origin") {
    // do stuff using origin
}

origin = resp.get("origin").unwrap()
// will panic if None

resp.get("origin").map(|origin| {
    // do stuff using inner value, returning another option
})

resp.get("origin").and_then(|origin| {
    // same as map but short-circuits if there is no inner value
})