[Boost-bugs] [Boost C++ Libraries] #7548: Impossible to query for std::vector<double> converter registration

Subject: [Boost-bugs] [Boost C++ Libraries] #7548: Impossible to query for std::vector<double> converter registration
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-10-21 19:20:18

#7548: Impossible to query for std::vector<double> converter registration
-----------------------------------------------+----------------------------
 Reporter:  Dario Izzo <dario.izzo@…>          |       Owner:  rwgk   
     Type:  Bugs                               |      Status:  new    
Milestone:  To Be Determined                   |   Component:  Python 
  Version:  Boost Release Branch               |    Severity:  Problem
 Keywords:                                     |  
-----------------------------------------------+----------------------------
 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.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7548>
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