Regel Regel - 1 year ago 191
C++ Question

boost::program_options config file option with multiple tokens

I can not seem to be able to read from config file multitoken options like I can from command line. What is the syntax for the config file?

This is how the option description is added:

- - -
po::options_description* generic;
generic=new po::options_description("Generic options");
("coordinate",po::value<std::vector<double> >()->multitoken(),"Coordinates (x,y)");

After which I parse command and config-files.

On command line '--coordinate 1 2' works. However, when I try in config file:

coordinate = 1,2


coordinate= 1 2

It fails giving a invalid_option_value exception. So what exactly is the syntax for config files in case of multitoken options?

Answer Source

You can achieve the behavior you seek by writing a custom validator. This custom validator accepts :

./progname --coordinate 1 2
./progname --coordinate "1 2"
#In config file:
coordinate= 1 2

Here is the code:

struct coordinate {
  double x,y;

void validate(boost::any& v,
  const vector<string>& values,
  coordinate*, int) {
  coordinate c;
  vector<double> dvalues;
  for(vector<string>::const_iterator it = values.begin();
    it != values.end();
    ++it) {
    stringstream ss(*it);
    copy(istream_iterator<double>(ss), istream_iterator<double>(),
    if(!ss.eof()) {
      throw po::validation_error("Invalid coordinate specification");
  if(dvalues.size() != 2) {
    throw po::validation_error("Invalid coordinate specification");
  c.x = dvalues[0];
  c.y = dvalues[1];
  v = c;
    po::options_description config("Configuration");
        ("coordinate",po::value<coordinate>()->multitoken(),"Coordinates (x,y)")