Method help

gecode/driver/options.cpp:127–132

      return 0;
    }
    void
    StringValueOption::help(void) {
      std::cerr << '\t' << iopt << " (string) default: "
                << ((cur == nullptr) ? "NONE" : cur) << std::endl
                << "\t\t" << exp << std::endl;
    }
    StringValueOption::~StringValueOption(void) {
      strdel(cur);
    }