Compilare: warning: unused imports: `ErrorKind`, `Error`, `self` --> main.rs:4:15 | 4 | use std::io::{self, BufWriter, BufReader, BufRead, Write, Error, ErrorKind}; | ^^^^ ^^^^^ ^^^^^^^^^ | = note: #[warn(unused_imports)] on by default warning: variable does not need to be mutable --> main.rs:20:9 | 20 | let mut iter = read("adunare.in"); | ----^^^^ | | | help: remove this `mut` | = note: #[warn(unused_mut)] on by default