#include <utility>
#include <iostream>

template<template<typename T> class F, typename... Ts>
void dispatch(int x, Ts&& ...args) {
  if (x > 0)
    F<int>()(std::forward<Ts>(args)...);
  else
    F<double>()(std::forward<Ts>(args)...);
}

template<typename T>
struct bla {
  void operator()(int&& a, char&& b, double&& c) const {
    std::cout << typeid(T).name() << " " << a << " " << b << " " << c << std::endl;
  }
};


main() {
  std::cout << "main()" << std::endl;
  //bla<double>()(1, 'a', 5.5);
  dispatch<bla, int, char, double>(5, 1, 'a', 5.5);
  dispatch<bla, int, char, double>(-5, 1, 'a', 5.5);
}