Hi, check out this code: #include <boost/lexical_cast.hpp> #include <iostream> struct my_type { int a; int b; }; template<typename C, typename T> std::basic_istream<C,T> &operator>>(std::basic_istream<C,T> &is, my_type &mt) { is >> mt.a >> mt.b; return is; } int main() { std::string input = "1 2"; my_type mt; try { mt = boost::lexical_cast<my_type>(s); std::cout << "TEST 1: " << mt.a << " " << mt.b << std::endl; } catch (boost::bad_lexical_cast &) { std::cout << "TEST 1 FAILED" << std::endl; } input = "3 4"; std::stringstream ss; ss << s; ss >> mt >> std::ws; if (ss.eof()) std::cout << "TEST 2: " << mt.a << " " << mt.b << std::endl; else std::cout << "TEST 1 FAILED" << std::endl; return 0; } The output I get is: TEST 1 FAILED TEST 2: 3 4 My investigation has shown that this occurs because boost::lexical_cast calls stream.unsetf(std::ios::skipws); My question is, why does it do this - as this specifically stops lexical_cast from working with complex types. So could this be an option, or completely disabled, or made an option (somehow) to lexical_cast? I understand some logic to not skipping whitespace, however I believe its use is limited - especially since there is a specialization for std::string and std::wstring already which does not even use operator>>. As a side note, yes, I could change my operator>>, however the sample operator>> above is typical for an operator>> for a complex class, almost always they assume that skipws is turned on, and don't bother checking. -- PreZ :) Founder. The Neuromancy Society (http://www.neuromancy.net)