C++ binding variadic template

[krakengore]

The nearest thing i could achieve is this:
    
    
    import macros
    
    {.emit: """/*TYPESECTION*/
    #include <tuple>
    #include <utility>
    
    template <typename... Types>
    struct TTuple : std::tuple<Types...>
    {
    };
    
    """.}
    
    type
        TTuple1[T] {.importcpp:"TTuple<'*0>".} = object
        TTuple2[T1, T2] {.importcpp:"TTuple<'*0, '*1>".} = object
    
    macro TTuple(types: varargs[untyped]): untyped =
        result = nnkBracketExpr.newTree newIdentNode("TTuple" & $len(types))
        for t in types:
            result.add newIdentNode($t)
    
    var x1 : TTuple(int)
    discard x1
    
    var x2 : TTuple(int, float)
    discard x2
    
    
    Run

But accessing by index needs some work, tried adding these:
    
    
    proc `[]=`[T](this: var TTuple1[T], idx: int, value: T) 
{.importcpp:"std::get<#>(#) = #;".}
    proc `[]`[T](this: var TTuple1[T], idx: int): T 
{.importcpp:"std::get<#>(#)".}
    
    
    Run

but unfortunately there is no way to substitute arguments to importcpp by 
positional index when using #