#include <iostream>
#include <thread>
#include <variant>
#include <functional>

using namespace std ;

template <typename Callable>
class Proxy {
  Callable c_;

public:
  Proxy(Callable c) : c_{ std::move(c) } {}

  template <typename... Args>
  decltype(auto) operator()(Args&&... args) {
    // ...
    return std::invoke(c_, std::forward<Args>(args)...);
  }
};



int add2Nos( int x1 , int y1 )
{
   return x1 + y1 ;
}



int main()
{
	//Lambda
	const auto add = [](int x, int y) { return x + y; };
	Proxy p1{ add };
	int result = p1(1, 2); // == 3
    cout << "result: " << result << endl ;

    //Regular function
	Proxy p2{ add2Nos };
	result = p2( 3, 4  ); // == 3
    cout << "result: " << result << endl ;



	return 1 ;
}