如何使用Boost :: bind与可变长度模板参数？

Question

boost::asio::thread_pool是一个非常有用的线程池实例，但是它不限制任务数量。您可以在其中发布任意数量的任务。有时会占用大量内存。而且我想使用boost::asio::thread_pool来实现一个限制任务数量的线程池。

这是我的代码：

class threadpool{
public:
    threadpool(int n):threads(n),thnum(n),count(0),stopflag(false){}
    ~threadpool(){
        stop();
    }
    void stop(){
        stopflag=true;
        cond.notify_all();
        threads.stop();
    }
    template<typename F, typename...Args>
    void post(F &&f, Args&&...args) {
        boost::unique_lock<boost::mutex> lock(mute);
        cond.wait(lock,[this]{
            return stopflag || count < 2*thnum;// task number less than 2x thread number
        });
        ++count;
        // The next line doesn't compile
        boost::asio::post(threads,boost::bind(&threadpool::post_func,this,std::forward<F>(f), std::forward<Args>(args)...));
    }
private:
    boost::asio::thread_pool threads;
    int count;// task number
    int thnum;// thread number
    bool stopflag;
    boost::mutex mute;
    boost::condition_variable_any cond;

    template<typename F, typename...Args>
    void post_func(F &&f, Args&&...args){
        boost::unique_lock<boost::mutex> lock(mute);
        --count;
        cond.notify_one();
        lock.unlock();
        auto func=boost::bind(std::forward<F>(f), std::forward<Args>(args)...);
        func();
    }
};

然后我得到了

../thpl.cpp: In instantiation of 'void threadpool::post(F&&, Args&& ...) [with F = void (print_task::*)(); Args = {print_task*}]':
../thpl.cpp:61:34:   required from here
../thpl.cpp:25:46: error: no matching function for call to 'bind(<unresolved overloaded function type>, threadpool*, void (print_task::*)(), print_task*)'
         boost::asio::post(threads,boost::bind(&threadpool::post_func,this,std::forward<F>(f), std::forward<Args>(args)...));
                                   ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

后面有很多note:。

那么如何将Boost :: bind与可变长度模板参数一起使用？我做错了什么？