请教代码里引用的值为什么没被修改

tweyseo

1. void print(const boost::system::error_code& /*e*/, boost::asio::deadline_timer* dt_ptr, int& count)
   
2. {  
   
3.     if (count < 5)
   
4.     {   
   
5.         std::cout << count << " " << std::endl;   
   
6.         ++count;
   
7.         dt_ptr->expires_at(dt_ptr->expires_at() + boost::posix_time::seconds(1));
   
8.         dt_ptr->async_wait(boost::bind(print, boost::asio::placeholders::error, dt_ptr, count));
   
9.     }
   
10. }
    
11. 
    
12. int main()
    
13. {
    
14.     boost::asio::io_service io_ser;   
    
15.     int count = 0;
    
16.     boost::asio::deadline_timer dt(io_ser, boost::posix_time::seconds(1));
    
17. 
    
18.     dt.async_wait(boost::bind(&print, boost::asio::placeholders::error, &dt, count));
    
19.     io_ser.run();
    
20. 
    
21.     std::cout << "final count is " << count << " "; // 这里输出还是0,为什么呢
    
22. 
    
23.     return 0;
    
24. }

复制代码

求解释

tweyseo

大家帮帮忙呀

hellioncu

不懂boost，我猜问题出在boost::bind(&print, boost::asio::placeholders::error, &dt, count)

tweyseo

大家懂得帮看看呀