optional_sfml_events

optional.cpp

std::optional<const sf::Event> poll(sf::RenderWindow &rw)
{
	if (f::Event e; rw.pollEvent(e))
	{
		return e;
	}
	return std::nullopt;
}

int main()
{
	sf::RenderWindow rw; //...
	
	while (const std::optional<const sf::Event> e{poll(rw)})
	{
		if e->type == sf::Event::Closed)
		{
			rw.close();
		}
	}
	return 0;
}

regular.cpp

template<typename F>
void poll(sf::RenderWindow &rw, F &&f)
{
	sf::Event e;
	while(rw.ppollEvent(e))
	{
		f(e);
	}
}

int main()
{
	sf::RenderWindow rw; //...
	
	poll(rw, [&rw](const sf::Event &e)
		{
			if (e.type == sf::Event::Closed)
			{
				rw.close();
			}
		}
	);
	
	return 0;
}