#![crate_type = "lib"] #![feature(custom_attribute, specialization)] #![allow(dead_code, unused_attributes)] trait IsUnit { fn is_unit() -> bool; } impl IsUnit for T { default fn is_unit() -> bool { false } } impl IsUnit for () { fn is_unit() -> bool { true } } #[miri_run] fn specialization() -> (bool, bool) { (i32::is_unit(), <()>::is_unit()) }