error[E0435]: attempt to use a non-constant value in a constant --> $DIR/non-constant-expr-for-arr-len.rs:5:22 | LL | fn bar(n: usize) { | - this would need to be a `const` LL | let _x = [0; n]; | ^ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0435`.