JustWrittingItOut.cpp

  template<typename T>
  Iterator<T> operator + (Iterator<T> lhs, int const rhs) {return lhs += rhs;}
  template<typename T>
  Iterator<T> operator - (Iterator<T> lhs, int const rhs) {return lhs -= rhs;}
  template<typename T>
  Iterator<T> operator * (Iterator<T> lhs, int const rhs) {return lhs *= rhs;}
  template<typename T>
  Iterator<T> operator / (Iterator<T> lhs, int const rhs) {return lhs /= rhs;}

UsingMacro.cpp

#define OP_FROM_SELF_ASSIGN_OP(op)                           \
  template<typename T>                                       \
  Iterator<T> operator op (Iterator<T> const & lhs,          \
                           int const rhs)                    \
  {                                                          \
      Iterator<T> copy = Iterator<T>(lhs);                   \
      copy op ## = rhs;                                      \
      return copy;                                           \
  }
  
  OP_FROM_SELF_ASSIGN_OP(+)
  OP_FROM_SELF_ASSIGN_OP(-)
  OP_FROM_SELF_ASSIGN_OP(*)
  OP_FROM_SELF_ASSIGN_OP(/)