unit_arithimetic.nim

type
  Tunits = tuple
    s, m: int
  Tsym = object
    val: int
    unit: Tunits

proc `+` (a, b: Tunits): Tunits =
  for i in 0 .. 1:
    result[i] = a[i] + b[i]  # Error: cannot evaluate at compile time: i
        
proc `*` (a, b: Tsym): Tsym = 
  result.val = a.val * b.val
  result.unit = a.unit + b.unit
  
let fourSeconds = Tsym(4, Tunits(1,0))
echo repr( fourSeconds * fourSeconds ) # should output something like {val: 8, {s: 2, m: 0}}