// staticAssertGcd.cpp
#include <iostream>
#include <type_traits>
template<typename T>
T gcd(T a, T b){
  static_assert(std::is_integral<T>::value, "T should be an integral type!");
  if( b == 0 ){ return a; }
  else{
    return gcd(b, a % b);
  }
}
int main(){
  std::cout << std::endl;
  std::cout << gcd(3.5, 4.0)<< std::endl; // should be gcd(3, 4)
  std::cout << gcd("100", "10") << std::endl; // should be gcd(100, 10)
  std::cout << std::endl;
}