Exception-based isEven in C++. >;D

whyyyyy.cxx

#include <limits>
#include <exception>

class OverflowException : public std::exception
{
};

struct SafeInt
{
  int n;
  SafeInt(int n) : n(n) { }
  operator int() { return n; }
  int operator +(int addend)
  {
    if (std::numeric_limits<int>::max() - addend > n)
      throw OverflowException();

    return n + addend;
  }
};

bool isEven(SafeInt n)
{
  try
  {
    if (n == std::numeric_limits<int>::max())
      return false;
    else
      return isEven(n + 2);
  }
  catch (OverflowException ox)
  {
    return true;
  }
}