Feature Request: `multizip_longest`

[owenthewizard]

Like the title says, a multizip version of zip_longest.
Here's how I imagine it working:

Enum AtLeastOneOf {
    One(i32),
    Two(i32, i32),
    Three(i32, i32, i32),
    Four(i32, i32, i32, i32),
    N(...),
}

let a = [1, 2];
let b = [3, 4, 5, 6];
let c = [];
let d = [7, 8, 9];
...

let i = multizip!(a, b, c, d);
match i {
AtLeastOneOf::One(x) => ...,
AtLeastOneOf::Two(x, y) => ...,
AtLeastOneOf::Three(x, y, z) => ...,
AtLeastOneOf::Four(x, y, z, aa) => ...,
}

Not sure if it could actually be implemented, or how to handle the order. Would probably need to be more like a tuple of options...