#include <boost/lexical_cast.hpp>

 #include <iostream>

 int main()

 {

     using boost::lexical_cast;

     int a = lexical_cast<int>("");

     double b = lexical_cast<double>("123.12");

     std::cout<<a<<std::endl

     std::cout<<b<<std::endl;

     return ;

 }

 #include <boost/lexical_cast.hpp>

 #include <string>

 #include <iostream>

 int main()

 {

     using std::string;

     const double d = 123.12;

     string s = boost::lexical_cast<string>(d);

     std::cout<<s<<std::endl;

     return ;

 }

 #include <boost/lexical_cast.hpp>

 #include <iostream>

 int main()

 {

     using std::cout;

     using std::endl;

     int i;

     try

     {

         i = boost::lexical_cast<int>("xyz");

     }

     catch(boost::bad_lexical_cast& e)

     {

         cout<<e.what()<<endl;

         return ;

     }

     cout<<i<<endl;

     return ;

 }