#![deny(patterns_in_fns_without_body)] trait Tr { fn f1(mut arg: u8); //~ ERROR patterns aren't allowed in functions without bodies //~^ WARN was previously accepted fn f2(&arg: u8); //~ ERROR patterns aren't allowed in functions without bodies fn g1(arg: u8); // OK fn g2(_: u8); // OK #[allow(anonymous_parameters)] fn g3(u8); // OK } fn main() {}