#![cfg(feature = "helper-traits")] use pretty_assertions::assert_eq; use std::num::ParseIntError; use error_log::ErrorLog; fn main() { let mut out = ErrorLog::new(); run(&mut out); } fn run(out: &mut ErrorLog) { assert_eq!(0, out.entries().len()); *out *= "ab12".parse::(); assert_eq!(**out, None); }