warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes --> $DIR/specialization-transmute.rs:3:12 | LL | #![feature(specialization)] | ^^^^^^^^^^^^^^ | = note: see issue #31844 for more information = help: consider using `min_specialization` instead, which is more stable and complete = note: `#[warn(incomplete_features)]` on by default error[E0284]: type annotations needed --> $DIR/specialization-transmute.rs:15:23 | LL | fn intu(&self) -> &Self::Id { | ^^^^^^^^^ cannot infer type | = note: cannot satisfy `::Id == _` error: aborting due to previous error; 1 warning emitted For more information about this error, try `rustc --explain E0284`.