error: to use a constant of type `Foo` in a pattern, `Foo` must be annotated with `#[derive(PartialEq, Eq)]` --> $DIR/ice-6254.rs:13:9 | LL | FOO_REF_REF => {}, | ^^^^^^^^^^^ | = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #62411 = note: `-D indirect-structural-match` implied by `-D warnings` error: aborting due to previous error