text: // Copyright (c) 2009-2014 Vladimir Batov.
  // Use, modification and distribution are subject to the Boost Software License,
  // Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
  
  //[lexical_cast_headers1
  #include <boost/convert.hpp>
  #include <boost/convert/lexical_cast.hpp>
  #include <boost/detail/lightweight_test.hpp>
  
  using std::string;
  using boost::convert;
  using boost::lexical_cast;
  
  struct boost::cnv::by_default : public boost::cnv::lexical_cast {};
  //]
  
  int
  main(int argc, char const* argv[])
  {
      //[lexical_cast_example1
      int    i1 = lexical_cast<int>("123");         // Throws if the conversion fails.
      int    i2 = convert<int>("123").value();      // Throws if the conversion fails.
      int    i3 = convert<int>("uhm").value_or(-1); // Returns -1 if the conversion fails.
      string s1 = lexical_cast<string>(123);
      string s2 = convert<string>(123).value();
  
      BOOST_TEST(i1 == 123);
      BOOST_TEST(i2 == 123);
      BOOST_TEST(i3 == -1);
      BOOST_TEST(s1 == "123");
      BOOST_TEST(s2 == "123");
      //]
  
      return boost::report_errors();
  }
  