#include <iostream>
#include <algorithm>
#include <vector>
#include <stdexcept>

using namespace std;

class ExpectFail {
  public:
    string message;

    ExpectFail(string m) : message(m) {};
};

void expect(bool test, string msg) {
  if(!test) {
    throw ExpectFail("Expectation failed.");
  }
}

int area(int length, int width) {
  expect(length > 0 && width > 0, "Bad area given.");

  return  length * width;
}

int main() {
  vector<int> numbers;

  try {
    numbers.push_back(100);
    numbers.push_back(-100);

    cout << "Area " << area(numbers.at(1), 100) << "\n";

    return 0;
  } catch(out_of_range &e) {
    cout << "Out of range ERROR: " << e.what() << "\n";
    return 2;
  } catch(...) {
    cout << "Exception: something went wrong\n";
    return 3;
  }
}