Function chalk_solve::clauses::push_auto_trait_impls

pub fn push_auto_trait_impls<I: Interner>(
    builder: &mut ClauseBuilder<'_, I>,
    auto_trait_id: TraitId<I>,
    ty: &TyKind<I>,
) -> Result<(), Floundered>

FIXME(#505) update comments for ADTs For auto-traits, we generate a default rule for every struct, unless there is a manual impl for that struct given explicitly.

So, if you have impl Send for MyList<Foo>, then we would generate no rule for MyList at all – similarly if you have impl !Send for MyList<Foo>, or impl<T> Send for MyList<T>.

But if you have no rules at all for Send / MyList, then we generate an impl based on the field types of MyList. For example given the following program:

#[auto] trait Send { }

struct MyList<T> {
    data: T,
    next: Box<Option<MyList<T>>>,
}

we generate:

forall<T> {
    Implemented(MyList<T>: Send) :-
        Implemented(T: Send),
        Implemented(Box<Option<MyList<T>>>: Send).
}