error: const `impl` for trait `A` which is not marked with `#[const_trait]` --> $DIR/const-impl-requires-const-trait.rs:8:12 | LL | pub trait A {} | - help: mark `A` as const: `#[const_trait]` ... LL | impl const A for () {} | ^ | = note: marking a trait with `#[const_trait]` ensures all default method bodies are `const` = note: adding a non-const method body in the future would be a breaking change error: aborting due to 1 previous error