{

if ('@' == s[0])

return std::make_pair(string("response-file"), s.substr(1));

else

return pair<string, string>();

{

try {

options_description desc("Allowed options");

desc.add_options()

("help", "produce a help message")

("include-path,I", value< vector<string> >()->composing(),

"include path")

("magic", value<int>(), "magic value")

("response-file", value<string>(),

"can be specified with '@name', too")

;

variables_map vm;

store(command_line_parser(ac, av).options(desc)

.extra_parser(at_option_parser).run(), vm);

if (vm.count("help")) {

cout << desc;

}

if (vm.count("response-file")) {

// Load the file and tokenize it

ifstream ifs(vm["response-file"].as<string>().c_str());

if (!ifs) {

cout << "Could not open the response file\n";

return 1;

}

// Read the whole file into a string

stringstream ss;

ss << ifs.rdbuf();

// Split the file content

char_separator<char> sep(" \n\r");

string sstr = ss.str();

tokenizer<char_separator<char> > tok(sstr, sep);

vector<string> args;

copy(tok.begin(), tok.end(), back_inserter(args));

// Parse the file and store the options

store(command_line_parser(args).options(desc).run(), vm);

}

if (vm.count("include-path")) {

const vector<string>& s = vm["include-path"].as<vector< string> >();

cout << "Include paths: ";

copy(s.begin(), s.end(), ostream_iterator<string>(cout, " "));

cout << "\n";

}

if (vm.count("magic")) {

cout << "Magic value: " << vm["magic"].as<int>() << "\n";

}

}

catch (std::exception& e) {

cout << e.what() << "\n";

}