// Illustrates that constexpr functions can be evaluated at run-time as well.

#include <iostream>

constexpr long int fib(int n){
  return (n == 0) ? 0 : (n == 1) ? 1 : fib(n - 1) + fib(n - 2);
} 

constexpr long int fac(int n){
 return (n == 0) ? 1 : n * fac(n - 1);
}

int main(){
  using namespace std;

  int i;
  cout << "Enter an integer: ";
  cin >> i;
  cout << "Fib(i): " << fib(i) << " fac(i): " << fac(i) << endl;
}