Is this kind of repeatable options possible with boost::program_options? - c++

Question

I have options --foo (short form -f) and --bar that need special treatment, they are repeatable and order should matter. So, for the following:
program --foo 1 --z -f 2 --bar 3 --x --foo 4
I'd like to range a key value map being able to construct [("foo", 1), ("foo", 2), ("bar", 3), ("foo", 4)].
Please notice the order of this array of tuples, it's the same as that in the command line. I've discarded non-important options in the array, but they may be present in the command line nonetheless.
It seems the sole way to allow repeatable options with boost::program_options is calling composing() for any given option, but then, since each will store all their values in a vector, I lose the order I need for interlacing options.
So, can boost::program_options help with this?
EDIT
I've asked for alternative software recommendations here: https://softwarerecs.stackexchange.com/questions/31766/
And answered it using Poco.

Answer 1

Assuming you can accept having to put an equals sign between the --foo and the value, this might do what you want:
#include <iostream>
#include <boost/program_options.hpp>
#include <vector>
#include <iterator>
#include <algorithm>
int main(int argc, const char**argv)
{
std::vector<int> foos;
boost::program_options::options_description desc("Command Line Options");
desc.add_options()
("foo,F", boost::program_options::value(&foos)->multitoken(), "integers for foo");
std::cout << desc << std::endl;
boost::program_options::variables_map vm;
boost::program_options::store(boost::program_options::parse_command_line(argc, argv, desc), vm);
boost::program_options::notify(vm);
std::copy(foos.begin(), foos.end(), std::ostream_iterator<int>(std::cout, ", "));
std::cout << std::endl;
return 0;
}
called with command line:
./a.out --foo=1 --foo=2
yields:
Command Line Options:
-F [ --foo ] arg integers for foo
1, 2,