rust/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.rs

// revisions: stock precise
#![feature(const_trait_impl)]
#![feature(const_mut_refs)]
#![feature(const_fn_trait_bound)]
#![cfg_attr(precise, feature(const_precise_live_drops))]

use std::marker::PhantomData;

struct NonTrivialDrop;

impl Drop for NonTrivialDrop {
    fn drop(&mut self) {
        println!("Non trivial drop");
    }
}

struct ConstImplWithDropGlue(NonTrivialDrop);

impl const Drop for ConstImplWithDropGlue {
    fn drop(&mut self) {}
}

trait A { fn a() { println!("A"); } }

impl A for NonTrivialDrop {}

struct ConstDropImplWithBounds<T: ~const A>(PhantomData<T>);
//~^ ERROR `~const` is not allowed

impl<T: ~const A> const Drop for ConstDropImplWithBounds<T> {
    fn drop(&mut self) {
        T::a();
    }
}

const fn check<T: ~const Drop>(_: T) {}

macro_rules! check_all {
    ($($exp:expr),*$(,)?) => {$(
        const _: () = check($exp);
    )*};
}

check_all! {
    NonTrivialDrop,
    //~^ ERROR the trait bound
    ConstImplWithDropGlue(NonTrivialDrop),
    //~^ ERROR the trait bound
    ConstDropImplWithBounds::<NonTrivialDrop>(PhantomData),
    //~^ ERROR the trait bound
    //~| ERROR the trait bound
}

fn main() {}