Registry

registry::global() can be used to access the singleton which allows users to register the logger globally, then we can create the logger by async_logger::builder.

registry::global().set_default_logger(
      async_logger::builder()
          .set_filter(filter::at_least(level::trace))
          .build());

After registering the logger, one or more async_writer s should be attached to the logger in order to determine where/how to log the messages.

// an stdout writer
registry::global().default_logger()->add_writer(make_async_stdout_writer());


// a file writer
registry::global().default_logger()->add_writer(
    make_async_stream_file_writer("./my_server.log"));