pub fn main(world: World) -> Void raises {
    var values: [4]u8 = [1, 2, 3, 4]
    let index: usize = std.search.indexOf(values, 3_u8)
    let len: usize = std.collections.moveToFront(values, 4_usize, index)
    if len == 4 && values[0] == 3_u8 && values[1] == 1_u8 {
        check world.out.write("move to front ok\n")
    }
}