By https://gitlab.com/D-z http://coliru.stacked-crooked.com/a/9167e1d86bb230ef

msg_queue.cpp

#include <string>
#include <vector>
#include <tuple>
#include <iostream>
#include <experimental/tuple>

#define HI std::cout << __PRETTY_FUNCTION__ << '\n';

template <class Sig>
struct MsgQueue;

template <class... Params>
struct MsgQueue<void(Params...)> {
    
    void operator()(Params... params) {
        HI
        _queue.emplace_back(std::forward<Params>(params)...);
    }
    
    template <class F>
    void operator >> (F &&f) {
        HI
        for(auto const &msg : _queue)
            std::experimental::apply(f, msg);
        _queue.clear();
    }
    
private:
    std::vector<std::tuple<Params...>> _queue;
};

//////////////////////////////////////////////////////////////////////////////////////////

struct Foo {
    MsgQueue<void(int amount, std::string from)> takeDamage;
    
    void update() {
        HI
        takeDamage >> [](int dmg, std::string from) {
            std::cout << "Taking " << dmg << " dmg from " << from << '\n';
        };
    }
};

int main() {
    Foo f;
    
    f.takeDamage(10, "Zblorg");
    f.takeDamage(15, "Glurb");
    
    std::cout << "-----------------\n";
    
    f.update();
}