#if !defined(BOOST_ASIO_HAS_THREADS)
# include <boost/asio/detail/null_thread.hpp>
+#elif defined(BOOST_ASIO_HAS_PTHREADS)
+# include <boost/asio/detail/posix_thread.hpp>
#elif defined(BOOST_ASIO_WINDOWS)
# if defined(UNDER_CE)
# include <boost/asio/detail/wince_thread.hpp>
# else
# include <boost/asio/detail/win_thread.hpp>
# endif
-#elif defined(BOOST_ASIO_HAS_PTHREADS)
-# include <boost/asio/detail/posix_thread.hpp>
#elif defined(BOOST_ASIO_HAS_STD_THREAD)
# include <boost/asio/detail/std_thread.hpp>
#else
#if !defined(BOOST_ASIO_HAS_THREADS)
typedef null_thread thread;
+#elif defined(BOOST_ASIO_HAS_PTHREADS)
+typedef posix_thread thread;
#elif defined(BOOST_ASIO_WINDOWS)
# if defined(UNDER_CE)
typedef wince_thread thread;
# else
typedef win_thread thread;
# endif
-#elif defined(BOOST_ASIO_HAS_PTHREADS)
-typedef posix_thread thread;
#elif defined(BOOST_ASIO_HAS_STD_THREAD)
typedef std_thread thread;
#endif