error[E0015]: cannot call non-const fn `core::slice::::get_unchecked::>` in constants --> $DIR/ub-slice-get-unchecked.rs:9:29 | LL | const B: &[()] = unsafe { A.get_unchecked(3..1) }; | ^^^^^^^^^^^^^^^^^^^ | = note: calls in constants are limited to constant functions, tuple structs and tuple variants error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0015`.