trait Foo<T> {}
impl Foo<()> for () { }

trait Slice {
    type Elem;
    type Query<'a> where Self::Elem: 'a, Self: 'a;

    fn query<F>(&mut self, f: F) -> bool
    where
        F: for<'a> Foo<Self::Query<'a>>;
}
impl<T> Slice for [T] {
    type Elem = T;
    type Query<'a> = () where T: 'a;

    fn query<F>(&mut self, _: F) -> bool
    where
        F: for<'a> Foo<()>, // yes
    {
        todo!()
    }
}
impl<S: Slice> Slice for &mut S {
    type Elem = S::Elem;
    type Query<'a> = S::Query<'a> where S::Elem: 'a, Self: 'a;

    fn query<F>(&mut self, f: F) -> bool
    where
        F: for<'a> Foo<Self::Query<'a>>, // oh no!
    {
        (**self).query(f)
    }
}

outputs:

   Compiling test_ v0.1.0 (/home/lrne/Project/Rust/test_)
error[E0477]: the type `&mut S` does not fulfill the required lifetime
    --> src/main.rs:3060:12
     |
3060 |         F: for<'a> Foo<Self::Query<'a>>, // oh no!
     |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0477]: the type `&mut S` does not fulfill the required lifetime
    --> src/main.rs:3058:8
     |
3058 |     fn query<F>(&mut self, f: F) -> bool
     |        ^^^^^

For more information about this error, try `rustc --explain E0477`.
error: could not compile `test_` (bin "test_") due to 2 previous errors

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