Compilare: warning: unused import: `std::io::Write` --> main.rs:2:5 | 2 | use std::io::Write; | ^^^^^^^^^^^^^^ | = note: `#[warn(unused_imports)]` on by default warning: unused variable: `out` --> main.rs:10:13 | 10 | let mut out = File::create("sr.out").unwrap(); | ^^^ help: if this is intentional, prefix it with an underscore: `_out` | = note: `#[warn(unused_variables)]` on by default warning: variable does not need to be mutable --> main.rs:10:9 | 10 | let mut out = File::create("sr.out").unwrap(); | ----^^^ | | | help: remove this `mut` | = note: `#[warn(unused_mut)]` on by default warning: 3 warnings emitted