c++ signals

main.cpp

#include <iostream>

#include "Signal.h"
#include "Signal.cpp" // I don't like this

int main(int argc, char* argv[]) {

	Signal<int, int> on_click;

	on_click.connect([](int a, int b) {
		std::cout << "A: " << a << " | B: " << b << std::endl;
	});

	on_click.trigger(2, 3); // same as on_click(2, 3)

	return 0;
}

Signal.cpp

#include <vector>
#include <functional>

#include "Signal.h"

template<typename ...Arguments>
void Signal<Arguments...>::connect(std::function<void (Arguments...)> listener) {
	listeners.push_back(listener);
}

template<typename ...Arguments>
void Signal<Arguments...>::trigger(Arguments... args) {
	for (auto &listener : listeners) {
		listener(args...);
	}
}

template<typename ...Arguments>
inline void Signal<Arguments...>::operator ()(Arguments... args){
	trigger(args...);
};

Signal.h

#pragma once

#include <vector>
#include <functional>

template<typename ...Arguments>
class Signal {
public:
	void connect(std::function<void (Arguments...)> listener);

	void trigger(Arguments... args);

	inline void operator ()(Arguments... args);
private:
	std::vector<std::function<void (Arguments...)>> listeners;
};