Function arg2double

example/multi_thread/thread_test.cpp:261–271

      exit(1);
   }
   double arg2double(
      const char* arg       ,
      double limit          ,
      const char* error_msg )
   {  double d = std::atof(arg);
      if( d >= limit )
         return d;
      std::cerr << "value = " << d << std::endl;
      std::cerr << error_msg << std::endl;
      exit(1);
   }
}

int main(int argc, char *argv[])