#![feature(const_indexing)] const FOO: [usize; 3] = [1, 2, 3]; const BAR: usize = FOO[5]; // no error, because the error below occurs before regular const eval const BLUB: [u32; FOO[4]] = [5, 6]; //~^ ERROR evaluation of constant value failed [E0080] //~| index out of bounds: the len is 3 but the index is 4 fn main() { let _ = BAR; }