Sophiar2/src/utility/tiny_signal.hpp

#ifndef SOPHIAR2_TINY_SIGNAL_HPP
#define SOPHIAR2_TINY_SIGNAL_HPP

#include <boost/intrusive/list.hpp>

#include <type_traits>

template<typename... Args>
class tiny_signal {
public:

    using hook_type = boost::intrusive::list_base_hook<
            boost::intrusive::link_mode<
                    boost::intrusive::auto_unlink>>;

    struct listener_type : public hook_type {
        virtual void on_signal_received(Args... args) = 0;
    };

    using list_type = boost::intrusive::list<
            listener_type, boost::intrusive::constant_time_size<false>>;

    void add_listener(listener_type &node) {
        if (node.is_linked()) {
            node.unlink();
        }
        node_list.push_back(node);
    }

    void emit_signal(Args... args) {
        for (auto &node: node_list) {
            node.on_signal_received(args...);
        }
    }

private:
    list_type node_list;

};

#endif //SOPHIAR2_TINY_SIGNAL_HPP