"Implement missing members" helper doesn't parenthesise compound traits behind references

[Tamschi]

Given

trait A<T: ?Sized> {
    fn a(&self) -> &T;
}
trait B {}

impl<'a, T: B> A<dyn 'a + B> for T {} // <-- not all trait items implemented, missing: `a` …

, using the "Implement missing members" command leads to the following code:

trait A<T: ?Sized> {
    fn a(&self) -> &T;
}
trait B {}

impl<'a, T: B> A<dyn 'a + B> for T {
    fn a(&self) -> &dyn 'a + B { // <-- Syntax Error: ambiguous `+` in a type
        todo!()
    }
}

This should be

trait A<T: ?Sized> {
    fn a(&self) -> &T;
}
trait B {}

impl<'a, T: B> A<dyn 'a + B> for T {
    fn a(&self) -> &(dyn 'a + B) { // <-- Ok
        todo!()
    }
}

instead, as after then applying the "use parentheses to disambiguate: …" helper.