error: methods called `as_*` usually take `self` by reference or `self` by mutable reference --> $DIR/def_id_nocore.rs:28:19 | LL | pub fn as_ref(self) -> &'static str { | ^^^^ | = note: `-D clippy::wrong-self-convention` implied by `-D warnings` = help: consider choosing a less ambiguous name error: aborting due to previous error