error[E0199]: implementing the trait `MySafeTrait` is not unsafe --> $DIR/coherence-default-trait-impl.rs:8:1 | LL | unsafe impl MySafeTrait for Foo {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | help: remove `unsafe` from this trait implementation | LL - unsafe impl MySafeTrait for Foo {} LL + impl MySafeTrait for Foo {} | error[E0200]: the trait `MyUnsafeTrait` requires an `unsafe impl` declaration --> $DIR/coherence-default-trait-impl.rs:13:1 | LL | impl MyUnsafeTrait for Foo {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: the trait `MyUnsafeTrait` enforces invariants that the compiler can't check. Review the trait documentation and make sure this implementation upholds those invariants before adding the `unsafe` keyword help: add `unsafe` to this trait implementation | LL | unsafe impl MyUnsafeTrait for Foo {} | ++++++ error: aborting due to 2 previous errors Some errors have detailed explanations: E0199, E0200. For more information about an error, try `rustc --explain E0199`.