#include <iostream>
#include <type_traits>

template<typename T>
auto testIfNumberType(T i) -> void {
  if (std::is_integral<T>::value || std::is_floating_point<T>::value) {
    std::cout << i << " is a number"
              << "\n";
  }
  else {
    std::cout << i << " is not a number"
              << "\n";
  }
}

auto main() -> int {
  auto i = int{6};
  auto l = long{7};
  auto d = double{3.14};
  testIfNumberType(i);
  testIfNumberType(l);
  testIfNumberType(d);
  testIfNumberType(123);
  testIfNumberType("Hello");
  auto s = "World";
  testIfNumberType(s);
}