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#[derive(Debug)] // <1>
struct File {
name: String,
data: Vec<u8>, // <2>
state: &'static str,
}
type FileMode = &'static str;
const OPEN: FileMode = "open";
const CLOSED: FileMode = "closed";
fn open(f: &mut File) -> bool {
f.state = OPEN;
true // <3> let's assume for the moment that this always succeeds
}
fn close(f: &mut File) -> bool {
f.state = CLOSED;
true // <3>
}
fn read(f: &File) -> (usize, Vec<u8>) {
(f.data.len(), f.data.clone())
}
fn main() {
let mut f2 = File {
name: String::from("2.txt"), // <3>
data: vec![],
state: CLOSED,
};
let f2_name = &f2.name.clone(); // <5>
open(&mut f2);
let (f2_length, _) = read(&f2);
close(&mut f2);
println!("{:?}", f2);
println!("{} is {} bytes long", f2_name, f2_length);
}
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