use std::fs::File; use std::io::ErrorKind; fn main() { let greeting_file_result = File::open("hello.txt"); let greeting_file = match greeting_file_result { Ok(file) => file, Err(error) => match error.kind() { ErrorKind::NotFound => match File::create("hello.txt") { Ok(fc) => fc, Err(e) => panic!("Problem creating the file: {:?}", e), }, other_error => { panic!("Problem opening the file: {:?}", other_error); } }, }; }