Out of curiosity, wish to know if BOOST ASIO calls like -

boost::asio::read()
boost::asio::transfer_all()
boost::asio::write()

BOOST LEXICAL calls like -
boost::lexical_cast<std::string>()

BOOST POSIX TIME calls like -
boost::posix_time::microsec_clock::universal_time()
boost::posix_time::microsec_clock::ptime()

are LIBRARY or SYSTEM calls.

How to know which calls of BOOST are SYSTEM and LIBRARY calls?

Thanks.