Nim v2: what would you change?

[cblake]

@nimoid \- I realize that it is not _exactly_ the same, but Nim already has 
`tuple`:
    
    
    type Foo = object
       f1: int
       f2: tuple[f3: int]
       f4: tuple[f5: int; f6: tuple[f7: float, f8: int]]
    
    var a = Foo(f4: (1, (2.0, 3)))
    var b: Foo
    b.f4.f6.f7 = 4.0
    echo a; echo b
    
    
    Run