Vector of std::function with variable Number of Arguments

I want to store event_handler into std::vector, then call listeners[index].handler_(args...).

I realise the above isn't possible, but I wonder if there are any alternatives I should consider.

template<class... Args>
using Handler = std::function<void(Args &&... args)>;

template<typename T>
struct event_handler  {
    event_handler(Handler<T> handler, bool once) : handler_(std::move(handler)), once_(once) {}

    Handler<T> handler_;
    bool once_;
};

std::vector<event_handler> listeners; // I known this line is wrong, here is example