#include <string>
#include <iostream>
#include <boost/lexical_cast.hpp>

using namespace std;

int main(int, char**)
{
  try {
    unsigned int a = boost::lexical_cast<unsigned int>(std::string("-1000"));
    cout << "a = " << a << endl;
  } catch (const boost::bad_lexical_cast &e)
    {
      cout << "exc. caught: " << e.what() << endl;
    }
  return 0;
}