rust-clippy/tests/compile-fail/partialeq_ne_impl.rs

#![feature(plugin)]
#![plugin(clippy)]

#![deny(warnings)]
#![allow(dead_code)]

struct Foo;

impl PartialEq for Foo {
    fn eq(&self, _: &Foo) -> bool { true }
    fn ne(&self, _: &Foo) -> bool { false }
    //~^ ERROR re-implementing `PartialEq::ne` is unnecessary
}

fn main() {}