const Error = error{
    unexpected_result,
};

const main = fn () Error!void{
    const a: [4]u8 = .{1, 2, 3, 4};
    const b: []const []const u8 = .{a.&}.&;

    var sum: u8 = 0;

    for (b) |b_slice| {
        for (b_slice) |a_element| {
            sum += a_element;
        }
    }

    if (sum - 10 != 0) {
        return Error.unexpected_result;
    }
}