#![feature(optin_builtin_traits)] use std::marker::Send; struct TestType; impl !TestType {} //~^ ERROR inherent impls cannot be negative trait TestTrait {} unsafe impl !Send for TestType {} //~^ ERROR negative impls cannot be unsafe impl !TestTrait for TestType {} //~^ ERROR negative impls are only allowed for auto traits struct TestType2(T); impl !TestType2 {} //~^ ERROR inherent impls cannot be negative unsafe impl !Send for TestType2 {} //~^ ERROR negative impls cannot be unsafe impl !TestTrait for TestType2 {} //~^ ERROR negative impls are only allowed for auto traits fn main() {}