[boost] Official boost macro to determine endianess?

What is the official boost macro to determine endianess? And what is the header to include to get it? I cannot find any help in the documentation of boost.endian but I can find those macros by grepping in boost: BOOST_LITTLE_ENDIAN, BOOST_BIG_ENDIAN, BOOST_ENDIAN_BIG_BYTE, BOOST_ENDIAN_BIG_WORD, BOOST_ENDIAN_LITTLE_BYTE, BOOST_ENDIAN_LITTLE_WORD, BOOST_PDP_ENDIAN Thanks, Frédéric