libboost1.49_thread compile error

./b2 -tx thread
...patience...
...found 527 targets...
...updating 3 targets...
gcc.compile.c++ bin.v2/libs/thread/build/gcc-4.8/debug/threading-multi/pthread/thread.o
In file included from ./boost/config.hpp:57:0,
                 from ./boost/thread/detail/config.hpp:10,
                 from libs/thread/src/pthread/thread.cpp:8:
./boost/optional/optional.hpp: In member function ‘void boost::optional_detail::optional_base<T>::construct(const Expr&, const boost::in_place_factory_base*)’:
./boost/static_assert.hpp:125:21: warning: typedef ‘boost_static_assert_typedef_355’ locally defined but not used [-Wunused-local-typedefs]
          BOOST_JOIN(boost_static_assert_typedef_, __LINE__)
                     ^
./boost/optional/optional.hpp:355:8: note: in expansion of macro ‘BOOST_STATIC_ASSERT’
        BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
        ^
./boost/optional/optional.hpp: In member function ‘void boost::optional_detail::optional_base<T>::construct(const Expr&, const boost::typed_in_place_factory_base*)’:
./boost/static_assert.hpp:125:21: warning: typedef ‘boost_static_assert_typedef_364’ locally defined but not used [-Wunused-local-typedefs]
          BOOST_JOIN(boost_static_assert_typedef_, __LINE__)
                     ^
./boost/optional/optional.hpp:364:8: note: in expansion of macro ‘BOOST_STATIC_ASSERT’
        BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
        ^
In file included from ./boost/bind/bind.hpp:29:0,
                 from ./boost/bind.hpp:22,
                 from ./boost/thread/detail/thread.hpp:22,
                 from ./boost/thread/thread.hpp:22,
                 from libs/thread/src/pthread/thread.cpp:10:
./boost/bind/arg.hpp: In constructor ‘boost::arg<I>::arg(const T&)’:
./boost/bind/arg.hpp:37:22: warning: typedef ‘T_must_be_placeholder’ locally defined but not used [-Wunused-local-typedefs]
         typedef char T_must_be_placeholder[ I == is_placeholder<T>::value? 1: -1 ];
                      ^
gcc.compile.c++ bin.v2/libs/thread/build/gcc-4.8/debug/threading-multi/pthread/once.o
gcc.link.dll bin.v2/libs/thread/build/gcc-4.8/debug/threading-multi/libboost_thread.so.1.49.0
...updated 3 targets...