问题

I understand that you want a translation of the code without the code part itself. Here is the translated text:

"If I have a struct that is something along the lines of:

struct Thing {
    opt: Option<Box<u32>>
}
fn main() {
    let thing = Thing{opt:Some(Box::new(5))};
    let pointer = &thing;
    match pointer.opt {
        None => println!("There is nothing"),
        Some(thing) => println!("There is a thing {}", thing)
    }
}

I get an error along the lines of: "cannot move out of 'pointer.opt' as enum variant 'Some' which is behind a shared reference"
Could someone please explain why this error happens and potential ways around it?

The thing I am working on requires working with a reference to a struct with a similar option in it."

struct Thing {
    opt: Option<Box<u32>>
}
fn main() {
    let thing = Thing{opt:Some(Box::new(5))};
    let pointer = &thing;
    match pointer.opt {
        None => println!("There is nothing"),
        Some(thing) => println!("There is a thing {}", thing)
    }
}

答案1

得分: 3

有std::option::Option::as_ref()来处理这种情况：

match pointer.opt.as_ref() {
    None => println!("There is nothing"),
    Some(thing) => println!("There is a thing {}", thing)
}

match pointer.opt.as_ref() {
    None => println!("There is nothing"),
    Some(thing) => println!("There is a thing {}", thing)
}