Impossible to query for std::vector<double> converter registration

[Dario Izzo <dario.izzo@…>]

I have been hitting this wall for some months now and produced some minimalistic code that shows the problem:

#include <boost/python.hpp>
#include <vector>
#include <iostream>


std::vector<double> list_of_doubles() {
	std::vector<double> retval;
	retval.push_back(3);
	retval.push_back(2);
	return retval;
}


// Instantiate the core module.
BOOST_PYTHON_MODULE(boost_debug)
{
//We check if a converter for std::vector has been registered
boost::python::type_info info = boost::python::type_id<std::vector<double> >(); 
const boost::python::converter::registration* reg = boost::python::converter::registry::query(info); 
//We output to screen the result (should be NULL)
std::cout << reg << " ";

//We also expose a function that needs such a conversion (to_python)
using namespace boost::python;
def("list_of_doubles",list_of_doubles);
}

in python:

import boost_debug

and the result (which should be zero) is instead an address: 0x7f9bc3c4c600

Even more absurdly, if we comment the line "def("list_of_doubles",list_of_doubles);" things actually go back to normality.

[anonymous]

See this answer on stackoverflow: ​http://stackoverflow.com/a/13017303/959926

It worked for me.