{"ast_node_type":"impl","tokens":[{"end":81,"kind":"keyword","start":0,"text":"//"}]}
                    // The match arms need to unify for the case of `impl Trait`.
                    && prior_arm.is_none_or(|(_, ty, _)| self.may_coerce(ty, ret_ty))
                    && !matches!(ret_ty.kind(), ty::Alias(ty::Opaque, ..))