=> very dumb example of processing messages from ten threads

    #include <boost/asio.hpp>
    
    #include <atomic>
    #include <iostream>
    #include <thread>
    
    int main() {
      boost::asio::io_context io;
    
      using work_guard_type = boost::asio::executor_work_guard<boost::asio::io_context::executor_type>;
      work_guard_type work_guard(io.get_executor());
    
      std::vector<std::jthread> t;
      for(int i = 0; i < 10; i++)
        t.emplace_back(std::jthread([&io] { io.run(); }));
      
      std::atomic_int counter{};
      while(counter < 100)
        io.post([&] { 
            std::cerr << std::this_thread::get_id() << '\n'; 
            counter++; 
        });
      
      io.stop();
      return 0;
    }