Help writing a macro that can accept a list of arguments of any arbitary type

[kaushalmodi]

I have a `proc` with `auto` argument type with works for any object type I pass 
to it. But I need to make 5 different calls of that proc for each object type.

So I am looking for a way to optimize that, and this pseudocode is what I have:
    
    
    type
      Foo = object
        someInt: int
        someStr: string
      
      Bar = object
        someBool: bool
        someStr: string
    
    proc doSomething(obj: auto): string =
      $obj
    
    let
      foo = Foo(someInt: 1000, someStr: "abc")
      bar= Bar(someBool: true, someStr: "def")
    
    echo doSomething(foo)
    echo doSomething(bar)
    
    # Trying to get something like below to work -- need help
    #[[
    macro printAllObjs(objs: varargs[untyped]): untyped =
      var
        str: string
      for obj in objs:
        str.add(doSomething(obj))
        str.add("\n")
      echo str
    
    printAllObjs(foo, bar)
    ]]#
    
    
    Run

<https://play.nim-lang.org/#ix=44We>

What would be the correct way to write that macro?

Thanks!