//@ run-pass #![allow(unused_doc_comments)] #![feature(auto_traits)] #![feature(negative_impls)] auto trait Auto {} unsafe auto trait AutoUnsafe {} impl !Auto for bool {} impl !AutoUnsafe for bool {} struct AutoBool(#[allow(dead_code)] bool); impl Auto for AutoBool {} unsafe impl AutoUnsafe for AutoBool {} fn take_auto(_: T) {} fn take_auto_unsafe(_: T) {} fn main() { // Parse inside functions. auto trait AutoInner {} //~ WARN trait `AutoInner` is never used unsafe auto trait AutoUnsafeInner {} //~ WARN trait `AutoUnsafeInner` is never used take_auto(0); take_auto(AutoBool(true)); take_auto_unsafe(0); take_auto_unsafe(AutoBool(true)); /// Auto traits are allowed in trait object bounds. let _: &(dyn Send + Auto) = &0; }