error[E0053]: method `len` has an incompatible type for trait --> $DIR/unsafe-trait-impl.rs:8:5 | LL | fn len(&self) -> u32 { *self } | ^^^^^^^^^^^^^^^^^^^^ expected unsafe fn, found normal fn | note: type in trait --> $DIR/unsafe-trait-impl.rs:4:5 | LL | unsafe fn len(&self) -> u32; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = note: expected signature `unsafe fn(&_) -> _` found signature `fn(&_) -> _` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0053`.