hir::ItemKind::Trait(.., ref generics, ref supertraits, _) => (generics, supertraits),
hir::ItemKind::TraitAlias(ref generics, ref supertraits) => (generics, supertraits),
_ => span_bug!(item.span, "super_predicates invoked on non-trait"),
hir::ItemKind::Trait(.., ref generics, ref supertraits, _) => (generics, supertraits),
hir::ItemKind::TraitAlias(ref generics, ref supertraits) => (generics, supertraits),
_ => span_bug!(item.span, "super_predicates invoked on non-trait"),