//@ compile-flags:--test //@ run-pass //@ needs-unwind use std::fmt; use std::fmt::{Display, Formatter}; pub struct A(Vec); impl Display for A { fn fmt(&self, _f: &mut Formatter<'_>) -> fmt::Result { self.0[0]; Ok(()) } } #[test] fn main() { let result = std::panic::catch_unwind(|| { let a = A(vec![]); eprintln!("{}", a); }); assert!(result.is_err()); }