src/test/ui/existential_types/not_well_formed.rs

// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![feature(existential_type)]

fn main() {
}

trait TraitWithAssoc {
    type Assoc;
}

existential type Foo<V>: Trait<V::Assoc>; //~ associated type `Assoc` not found for `V`

trait Trait<U> {}

impl<W> Trait<W> for () {}

fn foo_desugared<T: TraitWithAssoc>(_: T) -> Foo<T> {
    ()
}