#include <thread>

#include <mutex>
#include <future>
#include <atomic>
#include <condition_variable>

#include <memory>

#include <vector>
#include <forward_list>

template <typename T>
struct Message {
    std::unique_ptr<T> payload;
};

template <typename T>
struct Queue {
    std::forward_list<Message<T>> queue;
};

template <typename T>
struct Tunnel {};