Hello! I am trying to compile the following program from *Beyond the C++ Standard Library: An Introduction to Boost. *Here is the source code: #include <iostream> #include <string> #include "boost/lexical_cast.hpp" class lexical_castable { public: lexical_castable() { }; lexical_castable(const std::string s) : s_(s) { }; friend std::ostream& operator<<(std::ostream& o, const lexical_castable& le); friend std::istream& operator>>(std::istream& i, lexical_castable& le); private: virtual void print_(std::ostream& o) const; void read_( std::istream& i ); std::string s_; }; std::ostream& operator<<(std::ostream& o, const lexical_castable& le) { le.print_(o); return o; } std::istream& operator>>(std::istream& i, lexical_castable& le) { le.read_(i); return i; } void lexical_castable::read_( std::istream& i ) { i >> s_; } void lexical_castable::print_( std::ostream& o ) const { o << s_ <<"\n"; } int main(int argc, char* argv[]) { lexical_castable le(); std::cin >> le; int i=0; try { i = boost::lexical_cast<int>(le); std::cout << i << '\n'; } catch(boost::bad_lexical_cast &e) { std::cout << e.what() << '\n'; std::cout << "You were supposed to enter a number!\n"; } } The lexical_cast is throwing an exception as follows: ‡ boost::bad_lexical_cast::what returned 0x004c9888 "bad lexical cast: source type value could not be interpreted as target" const char * Note that I have modified the original code a bit because I was trying to figure out what went wrong. The object le is getting created successfully with the user entered "number" getting stored in the string s_ Please help. I am using Visual studio 2005 with boost v1.34