变量生存时间不够长:与Option类型匹配

我使用的是getopts,之前我从一个像这样的标志中获得了一个值:

let file = matches.opt_str("f").unwrap();
let file_path = Path::new(&file);

但是,我希望通过使路径可选来更好地处理可能的错误。这是我的新代码:

let file = matches.opt_str("f");
let file_path = match file {
    Some(f) => Some(Path::new(&f)),
    None    => None
}

但是,当我试图编译这段代码时,我得到了错误 'f' does not live long enough 。我完全被难住了。

这是我代码的MCVE:

use std::path::Path;

fn main() {
    let foo = Some("success".to_string());
    let string = match foo {
        Some(s) => Some(Path::new(&s)),
        None    => None
    };
}

error[E0597]: `s` does not live long enough
 --> src/main.rs:6:35
  |
5 |     let string = match foo {
  |         ------ borrow later stored here
6 |         Some(s) => Some(Path::new(&s)),
  |                                   ^^ - `s` dropped here while still borrowed
  |                                   |
  |                                   borrowed value does not live long enough