code: func (a *Arg) IsPtr() bool {
  	// Assumes all pointers are above 16Mb and positive.
  	return a.Value > 16*1024*1024 && a.Value < math.MaxInt64
  }
docs: // IsPtr returns true if we guess it's a pointer. It's only a guess, it can be
  // easily be confused by a bitmask.