#### Source listing for Timer.4

    //
    // timer.cpp
    // ~~~~~~~~~
    //
    // Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com)
    //
    // Distributed under the Boost Software License, Version 1.0. (See accompanying
    // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
    //

    #include <iostream>
    #include <asio.hpp>
    #include <boost/bind/bind.hpp>

    class printer
    {
    public:
      printer(asio::io_context& io)
        : timer_(io, asio::chrono::seconds(1)),
          count_(0)
      {
        timer_.async_wait(boost::bind(&printer::print, this));
      }

      ~printer()
      {
        std::cout << "Final count is " << count_ << std::endl;
      }

      void print()
      {
        if (count_ < 5)
        {
          std::cout << count_ << std::endl;
          ++count_;

          timer_.expires_at(timer_.expiry() + asio::chrono::seconds(1));
          timer_.async_wait(boost::bind(&printer::print, this));
        }
      }

    private:
      asio::steady_timer timer_;
      int count_;
    };

    int main()
    {
      asio::io_context io;
      printer p(io);
      io.run();

      return 0;
    }

Return to Timer.4 - Using a member function as a handler