src/test/ui/lint/warn-unused-inline-on-fn-prototypes.rs

#![deny(unused_attributes)]

trait Trait {
    #[inline] //~ ERROR `#[inline]` is ignored on function prototypes
    fn foo();
}

extern {
    #[inline] //~ ERROR `#[inline]` is ignored on function prototypes
    fn foo();
}

fn main() {}