-----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of anony Sent: Thursday, July 15, 2010 1:09 AM To: boost-users@lists.boost.org Subject: [Boost-users] boost::lexical_cast<> with hex strings? I'd like to do something like: boost::uint16_t b(std::lexical_castboost::uint16_t("xa")); I have no control of the string stream that lexical_cast uses internally, so how could I implement this? P.S.: There are a lot of false statements made about this functionality on the web, some people claim that boost::lexical_cast<> can do the conversion out of the box, but this is not so in my tests. What about doing this struct hexint { operator unsigned int() { return value; } unsigned int value; }; inline std::istream &operator>>(std::istream &in, hexint &rhs) { std::ios::fmtflags flags=in.flags(); in.unsetf(std::ios::oct); in.unsetf(std::ios::dec); in.unsetf(std::ios::hex); unsigned int temp=0; in >> temp; in.setf(flags); if(in.bad()) { throw boost::bad_lexical_cast(); } rhs.value=temp; return in; } //Then you can do hexint x=boost::lexical_cast<hexint>("0x2a");