How to write a template to call function with arbitrary number of arguments?

[alexeypetrushin]

I'm working with lots of different time series data, and trying to make 
shortcuts for object initialisation, to write code like that:
    
    
    echo OptionParams.init_seq @[
      ("call", 120.0, 1.2), ("call", 120.0, 1.3), ("call", 120.0, 1.5),
      ("call", 160.0, 1.2), ("call", 160.0, 1.3), ("call", 160.0, 1.5)
    ]
    
    
    Run

The problem is that `T.init_seq` function should accept tuples with **arbitrary 
number of elements** and translate it into the sequence of `T.init` calls.

I'm currently using a separate `init_seq` function for every number of elements 
(for 1, 2, 3 number of elements) could it be written in a better, general way, 
to work with any N number of elements?

[playground](https://play.nim-lang.org/#ix=2Ls9)
    
    
    import sequtils
    
    template init_seq*[R, A](_: type[R], list: seq[A]): seq[R] =
      list.map(proc (v: A): R = R.init(v))
    template init_seq*[R, A, B](_: type[R], list: seq[(A, B)]): seq[R] =
      list.map(proc (v: (A, B)): R = R.init(v[0], v[1]))
    template init_seq*[R, A, B, C](_: type[R], list: seq[(A, B, C)]): seq[R] =
      list.map(proc (v: (A, B, C)): R = R.init(v[0], v[1], v[2]))
    
    type OptionParams* = tuple
      right:     string
      tenor:     float
      moneyness: float
    
    func init*(_: type[OptionParams], right: string, tenor: float, moneyness: 
float): OptionParams =
      (right, tenor, moneyness)
    
    echo OptionParams.init_seq @[
      ("call", 120.0, 1.2), ("call", 120.0, 1.3), ("call", 120.0, 1.5),
      ("call", 160.0, 1.2), ("call", 160.0, 1.3), ("call", 160.0, 1.5)
    ]
    
    
    Run