Safe `enum` conversion

[ElegantBeef]

Realized how I could simplify the operations I was doing, and remove that pesky 
premature conversion, though... still uncertain if it resolved the 
afformentioned issues, just for posterity felt like posting :P 
    
    
    import std/macros
    type
      X = enum
        Z
    
    type
      HoleyEnum = enum
        AVal = -5
        BVal = 5
    
    macro enumAsSet(enm: typed): untyped = 
newNimNode(nnkCurly).add(enm.getType[1][1..^1])
    
    proc toEnum*(val: SomeInteger, E: typedesc[enum]): E =
      const enmRange = E.low.ord .. E.high.ord
      let enmSet = cast[set[E.low.ord .. E.high.ord]](enumAsSet(E)) # Vm cannot 
do the casting
      if val in enmRange and val in enmSet:
        E(val)
      else:
        raise (ref ValueError)(msg: $val & " cannot be converted to the enum: " 
& $E)
    
    let b = 0.toEnum(X)
    let c = (-5).toEnum(HoleyEnum)
    
    
    Run