// Adding the `mut` keyword makes an array variable mutable. function main() { let mut a = [1u32, 2u32, 3u32]; a[0u32..2u32] = [4u32, 5u32]; console.assert(a[0] == 4u32); console.assert(a[1] == 5u32); console.assert(a[2] == 3u32); }