struct interp(string str) { string toString() { return str; } }

​

auto asInterp(string str, Args...)(interp!str first, Args rest)

{

    import std.typecons : tuple;

    return tuple(first, rest);

}

​

import std.typecons : Tuple;

void takesInterp(string str, Args...)(Tuple!(interp!str, Args) tup)

{

    takesInterp(tup.expand);

}

void takesInterp(string str, Args...)(interp!str first, Args rest)

{

    import std.meta : AliasSeq;

    alias fullSeq = AliasSeq!(first, rest); // if you need

    // impl

}

​

void main()

{

    //   istr = i"abc ${1} bcd ${3}";

    auto istr = asInterp(interp!"abc "(), 1, interp!" bcd "(), 3);

    takesInterp(istr);

}