import std.typecons, std.typetuple, std.stdio, std.algorithm,

       std.range;

​

bool validAsRange(T)() {

    if (!isTuple!T || NoDuplicates!(T.Types).length != 1)

        return false;

    foreach (i, _; T.Types) // Useless?

        if (T.tupleof[i].offsetof != T.Types[0].sizeof * i)

            return false;

    return true;

}

​

T.Types[0][] asRange(T)(ref T tup) if (validAsRange!T()) {

    return (cast(T.Types[0]*)&tup[0])[0 .. T.length];

}

​

void main() { // demo

    auto a = [0];

    auto b = [5];

    auto c = [11];

    auto d = [22];

    Tuple!(int,int,int,int) tup = zip(a, b, c, d).front;

    auto result = tup.asRange.map!(x => x * 2).array;

    assert(result == [0, 10, 22, 44]);

    tup.expand.only.writeln;

}