error[E0005]: refutable pattern in function argument --> $DIR/const_let_refutable.rs:3:16 | LL | const fn slice(&[a, b]: &[i32]) -> i32 { | ^^^^^^^ patterns `&[]`, `&[_]` and `&[_, _, _, ..]` not covered | = note: the matched value is of type `&[i32]` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0005`.