Borrowed value not living long enough when collecting file names into a vector using rust

Question

I'm new to rust and trying to collect files into a string vector.

use glob::glob;
use std::env;

fn main() {
    let mut file_names: Vec<&str> = Vec::new();

    let cwd = env::current_dir().unwrap();

    for entry in glob(cwd.to_str().unwrap()).expect("Failed to read directory.") {
        match entry {
            Ok(file) => {
                println!("{:?}", file.file_name());
                let file_name = file.file_name().unwrap().to_str();
                file_names.push(file_name.unwrap());
            }
            Err(e) => println!("{:?}", e),
        }
    }
}

Receiving the following error.

error[E0597]: `file` does not live long enough
  --> src/main.rs:13:33
   |
13 |                 let file_name = file.file_name().unwrap().to_str();
   |                                 ^^^^ borrowed value does not live long enough
14 |                 file_names.push(file_name.unwrap());
   |                 ---------- borrow later used here
15 |             }
16 |             Err(e) => println!("{:?}", e),
   |               - `file` dropped here while still borrowed

error: aborting due to previous error

I'm not sure how to push the file names into the vector. Thanks!

The file names in your loop are all temporary variables, so you can't store references to them in a vector which outlives the loop. Instead, perhaps store `String`s in the vector? — Peter Hall, Feb 28 '20 at 16:06

score 0 · Answer 1 · answered Feb 28 '20 at 16:13

Thanks to @PeterHall this is the corrected code.

use glob::glob;
use std::env;

fn main() {
    let mut file_names: Vec<String> = Vec::new();

    let cwd = env::current_dir().unwrap();

    for entry in glob(cwd.to_str().unwrap()).expect("Failed to read logs directory.") {
        match entry {
            Ok(file) => {
                println!("{:?}", file.file_name());
                let file_name = file.file_name().unwrap().to_str().unwrap();
                file_names.push(file_name.to_string());
            }
            Err(e) => println!("{:?}", e),
        }
    }

    for file_name in file_names {
        println!("{:?}", file_name);
    }
}

Borrowed value not living long enough when collecting file names into a vector using rust

1 Answers1