#include <iostream>

template <typename T>
std::enable_if_t<std::is_integral<T>::value, T> fn(T x) {
  return x * x;
}

template <typename T>
std::enable_if_t<std::is_floating_point<T>::value, T> fn(T x) {
  return --x;
}

int main() {
  float x = 4.4;

  std::cout << "floating: " << fn((double)5.3) << "\nintegral: " << fn(4l);

  return 0;
}