Function echo

example/cpp20/coroutines/echo_server_with_default.cpp:28–43

namespace this_coro = boost::asio::this_coro;

awaitable<void> echo(tcp_socket socket)
{
  try
  {
    char data[1024];
    for (;;)
    {
      std::size_t n = co_await socket.async_read_some(boost::asio::buffer(data));
      co_await async_write(socket, boost::asio::buffer(data, n));
    }
  }
  catch (std::exception& e)
  {
    std::printf("echo Exception: %s\n", e.what());
  }
}

awaitable<void> listener()
{