#include <boost/program_options.hpp>
namespace po = boost::program_options;

int main(int argc, char** argv)
{
	int compression;
	po::options_description desc("Allow options");
	desc.add_options()
		("help", "produce help message")
		("compression", po::value<int>(), "set compression level");
		//("help,h", "produce help message")  
		//("compression", po::value<int>(&compression)->default_value(10), "set compression level");  
	
	po::variables_map vm;
	try
	{
		po::store(po::parse_command_line(argc, argv, desc), vm);
		po::notify(vm);
	}
	catch (...)
	{
		std::cout << "输入的参数中存在未定义的选项！\n";
		return 0;
	}

	if (vm.count("help"))
	{
		cout << desc << endl;
		return 1;
	}

	if (vm.count("compression"))
	{
		cout << "Compression level was set to " << compression << endl;
	}
	else
	{
		cout << "Compression level was not set." << endl;
	}
	return 0;
}
#include <boost/program_options.hpp>