// run-rustfix #![allow(unused_must_use)] #![warn(clippy::writeln_empty_string)] use std::io::Write; fn main() { let mut v = Vec::new(); // These should fail writeln!(v, ""); let mut suggestion = Vec::new(); writeln!(suggestion, ""); // These should be fine writeln!(v); writeln!(v, " "); write!(v, ""); }